5-9 chippenham gardens, kilburn park post ofﬁ ce, 4-26...

5-9 Chippenham Gardens, Kilburn Park Post Offi ce, 4-26 Stuart Road (even numbers only) together defi ned as

‘Land north of Chippenham Gardens’

Daylight, Sunlight &Overshadowing Assessment

SUSTAINABILITY

prp-co.uk

ArchitectureUrban DesignMasterplanningLandscapeSustainabilityProject ServicesPlanningTransport PlanningInteriorsResearch

PRP Job ReferenceAE4486

Project LeadCarolina Caneva

Report AuthorEvgenia Budanova

Version2.0 Final Issue

Issue Date 07 March 2016

ContentsExecutive Summary 1

Overview 1

Daylight 1

Impact on Surrounding Buildings 1

Impact on Surrounding Buildings 2

Sunlight criteria for Open Spaces 2

Overshadowing 2

Guidelines and Policy 3

Guidelines for Daylight and Sunlight 3

Regional Planning Policy 3

Sensitive Receptors 4

Relevant Defi nitions 4

Assessment Criteria - Daylight 5

Assessment Criteria - Sunlight 7

Project Background 11

Brief 11

The Site 11

Extent of the Study Area 12

Modelling Assumptions 12

Analysis and Calculations 12

Preliminary 25-degree line analysis 12

Daylight Results

Surrounding properties 13

Property 3 13

Property 4 13

Property 5 14

Property 6 14

Summary of Results 14

Daylight Results

Proposed development 16

Analysis assumptions 16

Average Daylight Factor (ADF) results 16

Sunlight Results 17

Surrounding properties 17

Property 4 17

Property 5 18


Sunlight Results

Proposed development 20

Sunlight analysis 20


Overshadowing Results 21

Open Spaces 21

Sunlight criteria for Open Spaces 22

Conclusion 23

Appendix A - Window numbering 25

Appendix B - Tabulated results 29

SUSTAINABILITY

1

The Sustainability team at PRP has been commissioned by Brent Council to undertake a Daylight, Sunlight and Overshadowing Assessment with respect to the Land North of Chippenham Gardens development, located in the London Borough of Brent.

Executive Summary

Overview1.1 The aim of the study is to investigate the potential

impact of the proposed scheme on daylight and sunlight access compared to what is currently being experienced by the surrounding adjacent properties, as well as the internal daylight and sunlight levels within the proposed habitable rooms.

1.2 The methodology used in this study is based on the guidance provided in the 2nd edition of Building Research Establishment (BRE) entitled: “Site Layout Planning for Daylight and Sunlight: a good practice guide” by PJ Littlefair (2011).

DaylightImpact on Surrounding Buildings1.3 The results of the assessment show that a majority of

the windows analysed in the surrounding properties will experience negligible impacts on their daylight access as a result of the proposed development.

1.4 A total of 2 nos.windows in Property 4, 3nos.windows in Property 5 and 3 nos.windows in Property 6 will receive minor adverse impacts, as a result of the proposed development. The results are discussed in detail in the daylight section of this report (Tables 4.2-4.4) and the windows identifi ed and illustrated in the images provided in Appendix A.

Proposed development1.5 The proposed development comprises 16 diff erent

unit types. A sample set of units which represent the worst case scenario across each unit type were chosen on the ground, fi rst and third fl oors and tested for their daylight availability.

1.6 A majority of the rooms tested within the proposed development (74%) receive daylight levels in compliance with the BRE requirements. The remaining 44 out of total 169 rooms tested, receive daylight levels that are below the minimum BRE threshold. This is mostly seen in the kitchens which have a higher threshold for daylight.

1.7 As the majority of the rooms meet the BRE recommended criteria, the daylight levels within the proposed development are considered acceptable, considering the dense urban context of the site.

2

SunlightImpact on Surrounding Buildings1.8 The results of the assessment show that a majority of

the windows that face the proposed development achieve good levels of sunlight access as a result of the proposed development, during the whole year and winter months.

1.9 A few windows located on Property 6 (209-223 Kilburn Park Road- odd numbers only), receive minor -moderate impacts. However, all rooms served by these windows have 1-2 other additional windows that are orientated away from the proposed development. Therefore, the rooms should continue to receive adequate levels of sunlight.

Proposed development1.10 The proposed development has 52 main living rooms,

most of the rooms have windows facing due south. They were all analysed in terms of Probable Sunlight Hours.

1.11 A majority of the living rooms tested (90.3%) fully comply with the minimum BRE threshold for annual and winter probable sunlight hours. A small proportion (9.6%) of the living rooms (5 rooms) do not meet the BRE requirements for the Probable Sunlight Hours.

1.12 Limited levels of sunlight is mainly recorded in the living rooms that are located along the courtyard elevations.

1.13 Sunlight availability to the most of the rooms of the proposed development is in accordance with BRE’s criterion for sunlight.

Sunlight criteria for Open SpacesOvershadowing1.14 An overshadowing analysis was carried out on 7 open

spaces. These are identifi ed and described below:

• Open Space 1SR: Rear garden of No. 1 Stuart Road Open Space 3SR: Rear garden of No.3 Stuart Road Open Space 5SR: Rear garden of No.5 Stuart Road

• Open Space 7SR: Rear garden of No.7 Stuart Road

• Open Space 9SR: Rear garden of No.9 Stuart Road Open Space 1AH: Open Space of Argo House

• Adjacent Public Highway: Existing open space adjacent to the development

1.15 The BRE Guide suggests that an open space will be considered to adequately sunlit throughout the year if it receives at-least 2 hours of direct sun on at least 50% of its total area on the 21st of March (Equinox).

1.16 The results of the analysis show that most of the open spaces and gardens associated with the neighbouring properties comply with the BRE Guidelines for solar access (Tables 6.1-6.3). One open space which is associated with the garden of 7 Stuart Road has a marginal impact from the proposed development. However, the loss of sunlight to this garden can be considered minor as the values are less than 1% outside the requirements.

SUSTAINABILITY

3

This analysis has been based on the BRE Site Layout Planning for Daylight and Sunlight report, which considers the potential impact on and quality of daylight and sunlight for surrounding properties as well as for new buildings.

Guidelines and Policy

Guidelines for Daylight and Sunlight 2.1 The BRE guideline document provides the criteria and

methodology for calculations pertaining to daylight and sunlight on both existing and proposed developments, and is the primary reference for this matter. Alongside this document, the BS 8206-02: Lighting for buildings - Part 2: Code of practice for daylight (2008), is also used as a guideline.

2.2 The BRE Guide is widely used to establish the extent to which the development meets current best practice guidelines, although it is not an offi cial instrument of planning policy and there are no legal or statutory requirements to meet these guidelines.

2.3 There are no National Planning Policy guidelines for sunlight and daylight. However, most Local Authorities recognise these guidelines as the most appropriate method for carrying out daylight, sunlight and overshadowing assessments.

2.4 The methods given in the document are widely used in the industry, and are technically robust, however some level of fl exibility should be applied where appropriate, particularly on sites with higher development densities, as these guidelines were primarily developed for characterising the nature of daylight and sunlight impact in general terms, which would include a range of rural, suburban and densely urban contexts.

Regional Planning Policy2.5 The statutory development plan covering the

proposal site is informed by the London Plan (2011) and any Local Development Framework (LDF) core strategies, Unitary Development Plans, and Supplementary Planning Documents relevant to the London Borough of Brent.

2.6 We have consulted with these documents to ensure that we meet any additional requirements set out by the Local Authority that are not covered by the BRE guidance.

The London Plan

2.7 The London Plan addresses the potential eff ects of a development in Policy 7.6 (Architecture), where it states that the proposed development must:

“not cause unacceptable harm to the amenity of surrounding land and buildings, particularly residential buildings, in relation to privacy, overshadowing, wind and micro-climate”.

2.8 “Guidance and Standards for Housing Development and House Conversions”, (2008): The main purpose is that good standards of daylight and sunlight should be achieved for new buildings and extensions.

2.9 The guidance in these documents accounts for material considerations whilst submitting planning applications and have been consulted for this assessment.

4

Sensitive Receptors2.10 In order to undertake the assessment, key sensitive

receptors around the site need to be identifi ed fi rst. These include habitable rooms in domestic and non-domestic buildings facing the site where occupants have a reasonable expectation of daylight or sunlight. According to the BRE Guide these include:

• Living rooms, kitchens and bedrooms in domestic buildings.

• Other rooms in schools, hospitals, hotels and hostels, small workshops and offi ces.

• Open spaces such as gardens, parks, playgrounds, swimming and paddling pools, sitting areas and focal points for views.

2.11 Rooms and spaces which will not be permanently occupied such as bathrooms, toilets, storerooms, circulation areas, garages, public footpaths, small front gardens and car parks do not need to be analysed.

Relevant Defi nitions2.12 “Natural light” refers to both daylight and sunlight.

2.13 For the purposes of this assessment, we have to distinguish between “daylight” and “sunlight” as the physical properties and therefore the perceived benefi ts for each type of light are diff erent.

2.14 Daylight is used to describe diff use light from the sky under overcast conditions. Daylight is orientation-independent and directly aff ects ambient light levels in internal spaces and the visual comfort related to the carrying out of day to day tasks.

2.15 Daylight for existing buildings is typically measured using Vertical Sky Component (VSC) and No-Sky Line (NSL), while daylight in proposed buildings are typically measured using Average Daylight Factor (ADF).

2.16 Sunlight is used to describe light coming directly from the sun. Sunlight is highly dependent on the site location, orientation and the time of day, and directly aff ects factors such as solar gain, perceptions of warmth and health issues such as the access to Vitamin D. Direct sunlight is desirable in winter, and not only yields psychological benefi t but also helps facilitate energy effi ciency by reducing the need for heating, however excessive levels of sunlight without solar protection could also lead to summertime overheating.

2.17 Sunlight is typically measured using Probable Sunlight Hours (PSH) for both existing and new buildings. Sunlight availability on open spaces is measured using overshadowing criterion, which requires at least half of the open amenity area to receive at least two hours of sunlight on the 21st of March.

2.18 In order to characterise the magnitude of impact on existing properties, we model these criteria fi rst with the existing buildings on site, to establish a baseline condition. The analysis results are then compared with the results when the proposed building is put in place. These “ratio-of-impact” calculations then form the basis for whether the development has a negligible, minor, moderate or signifi cant adverse/benefi cial impact on the daylight and sunlight amenity of the surrounding properties.

2.19 The BRE and BS8206 guidelines provide three main methods for assessing daylight availability. The basic principle behind these guidelines is that the ground fl oor windows (and above) of a new or existing building should have an adequate view of the sky.

2.20 We have developed some visual illustrations to describe the various calculations and criteria that go into a typical daylight and sunlight assessment. These are presented on the following pages.

References• BRE Site Layout and Planning for Daylight and

Sunlight: a guide to good practice. Second Edition. P. J. Littlefair (2011)

• BS8206-02 Lighting for buildings - Part 2: Code of practice for daylight (2008)

• Greater London Authority London Plan (2011)

• Lighting Guide 10 (LG10): Daylight - A guide for designers (2014). CIBSE

SUSTAINABILITY

5

PASS

START

25° LINEDoes the proposed development fall beneath a 25° angle taken from the lowest window?

VSCIs the Vertical Sky Component (VSC) of the window at least 27%?

No Sky LineIs the area within the No Sky Line depth at least 80% of its former value?

No

Yes

Yes

Yes

No

Yes

No

No

Yes

No

IF ROOM LAYOUTS ARE KNOWN

Daylightnot required

No Sky Line

NSL After>80% <80%

rteAft rteAftL AL ASLSLNN

NSL AfterNSL Before

100%

No Sky Line

Ratio ofImpactIs the Vertical Sky Component (VSC) at least 80% of its former value? 0

20

40

60

80

100

VSC Before VSC AfterVSC After

80%

If the DSO Assessment is part of an Environmental Impact Assessment report, Ratio of Impact can be further characterised as follows:

Impact-o-meter

< 20% reductionnegligible negative impactexpected; compliant with BRE guideline criteria

< 20 - 30% reductionminor adverse impact expected

< 30 - 50% reductionmoderate adverse impactsexpected

>50% reductionsubstantial adverse impactsexpected

0

20

40

60

80

100

*Are balconies the problem?If the VSC ratio of impact is at least 80% of its former value without the balconies on the existing neighboring propety, then the presence of the balcony is the main factor contributing to the relative loss of sunlight.

Is the room a habitable room?

IF ROOM LAYOUTS ARE KNOWN

FAIL If the development fails based on the preceding criteria, there is now an option to set alternative targets if these conditions are met:

Last chance!

Existing planning permission?If planning permission has been granted for the site but for a different massing design, the local authority may allow the VSC and APSH for the permitted scheme to be used as alternative benchmarks. The values of the proposed scheme should either meet or improve on these benchmark values.

Too close for comfort? Use mirror images!Neighbouring buildings sitting too close to the site boundary can be a problem in terms of daylight and sunlight, especially if you’re building on an empty site. In cases like these, VSC and APSH targets for existing buildings can be set using a ‘mirror-image’ building of the same height and size, an equal distance away on the other side of the boundary.

SETTING ALTERNATIVE

TARGETS

EXISTING BUILDINGSAssessment Criteria - Daylight

25 degree line

2.21 In the fi rst instance, if a proposed development falls beneath a 25° angle

plane taken from the centre point of the lowest window, along the extent of the window wall, then no further analysis is required as it is unlikely to have a substantial impact on natural light availability.

Vertical Sky Component

2.22 The second method tests the quantity of daylight. This is done through the Vertical Sky Component

(VSC) percentage calculated in the centre of the window. The VSC takes into consideration any obstruction to the visible sky to calculate the possible daylight reduction.

2.23 The BRE Guide sets out the guidelines for the VSC:

• If the VSC at the centre of the existing window exceeds 27% with the new development in place, then enough sky light should still be reaching the existing window.

• If the VSC with the new development in place is both less than 27% and less than 80% its former value, then the reduction in light to the window is likely to be noticeable.

• If the VSC is less than 27% but the sky light reduction is not lower than 80% its former value, then the impact would be considered negligible.

2.24 It is important to note that VSC does not quantify the actual daylight levels inside a room, just the potential for receiving daylight. A more detailed assessment such as the Average Daylight Factor is better equipped to assess this, however for existing buildings the information for the calculation is not always available.

DAYLIGHT

6

Yes

LimitingRoomDepth

Limiting Room DepthIs the depth of the room less than the limiting room depth value?

FAIL

PASS

ADF

No

No

No

MINIMUM ADF

Kitchens

2.0%

MINIMUM ADF

Bedrooms

1.0%MINIMUM ADF

Living/DiningRooms

1.5%

Calculate VSCVSC is an essential parameter for calculating ADF. The VSC-meter on the right gives an indication of how the visible sky angle θ relates to VSC and what the values mean in terms of design.

Does the Average Daylight Factor meet the minimum criteria?

VSC-meter

θ < 25° θ = 25-45° θ = 4

5-6

5° θ

> 6

5°

θ < 25°Impossible to achieve reasonable daylightVSC < 5%

θ

θ = 25-45°very difficult to provideadequate daylightVSC 5-15%

θ = 45-65°special measures neededto provide adequate daylight(need larger windows,changes to room layout)VSC 15-27%

θ > 65°conventional window designis usually enough to provideadequate daylightVSC >27%

START

PROPOSED DEVELOPMENTAverage Daylight Factor

2.25 For new developments the daylight quantity is calculated using the Average Daylight Factor (ADF). This test takes into consideration not only the VSC (Θ angle equivalent) but also the room and window dimensions, the refl ectance of internal surfaces and the visible light transmitted by the glass.

2.26 The VSC is a simplifi ed approach to assess the loss of daylight when no internal room information is known, as is usually the case for neighbouring properties. ADF provides better information as it measures the overall daylight in a space, but is usually used in new buildings where plans are known and the infl uencing factors are within designer’s control.

2.27 The ADF is the average illuminance on the working plane, divided by the illuminance on an unobstructed horizontal surface outdoors under CIE overcast sky conditions and is usually expressed as a percentage.

2.28 The calculated ADF is compared with the minimum values recommended in the BS 8206-2 from where the need for mitigation measures can be established.

2.29 The BS 8206-2 recommends an ADF of 5% or more for a predominantly daylit appearance and 2% for a for a partially lit one. An ADF below 2% will require supplementary electric lighting. For domestic buildings the BS 8206-2 recommends that the minimum ADF values are 1% in bedrooms, 1.5% in living rooms and dining rooms, and 2% in kitchens.

2.30 The CIBSE Guide LG10 defi nes the Average Daylight Factor as:

“…the measure of the amount of skylight in a room. If the room is not too deep or obstructed, an ADF >5% will ensure that an interior looks substantially daylit, except early in the morning, late in the afternoon or on exceptionally dull days. An ADF< 2% generally makes a room look dull; electric lighting is likely to be in frequent use”

No Sky Line and Limiting Room Depth

2.31 The third and fi nal method is used to evaluate the distribution of daylight using the No Sky Line (NSL)

and Room Depth Criteria. The no sky line divides areas of the working plane which can and cannot see the sky. Areas beyond the no sky line and the recommended maximum depth are usually darker as they receive no direct light.

2.32 The ADF and the Room Depth criteria are design tools that contribute to a suffi cient uniformity of illuminance between the front and the back of the room. The limiting depth criterion is based on the ratio between the ADF in the front and the rear half of the room.

2.33 The NSL analysis is undertaken at working plane height (0.85 m for dwellings and 0.7 for offi ces), its approach is similar to the VSC one in the sense that, if the area of the existing room beyond the no sky line is reduced less than 0.8 times its former value, then the reduction of light may be noticeable. In new buildings if a signifi cant area of the working plane (normally more than 20%) is beyond the no sky line, then daylight will be poorly distributed.

DAYLIGHT

SUSTAINABILITY

7

SUNLIGHT

Probable Sunlight HoursDo the windows of the main living room and/or conservatory receive at least 25% PSH throughout the year, with at least 5% PSH being received during the winter period between 21 March and 21 September?

minimum 5% of APSH

required duringwinter period (WPSH)

minimum 25% of APSH

required duringannual period (APSH)

SUNLIGHTHOURS

PSH

PASS

No

No

Yes

Yes

Yes

No

No

Bedrooms& Kitchenssunlightless essential

Living Rooms:sunlight

essential!

Room UseIs the room a living room or a conservatory?

NEW

DEVELOPMENT

New

dev

elopm

ent is with

in 90º due SOUTH of the existing window - CHECK SUN

LIGH

T AC

CE

SS

New

development is within 90º due NORTH of the existing window - NO NEED TO C

HECK

SU

NLI

GH

T A

CC

ES

S

OrientationDoes the window face within 90° of due south?

Yes

Yes

No

START

25° LINEDoes the proposed development fall beneath a 25° angle taken from the lowest window?

If the DSO Assessment is part of an Environmental Impact Assessment report, Ratio of Impact can be further characterised as follows:

Impact-o-meter

< 20% reductionnegligible negative impactexpected; compliant with BRE guideline criteria

< 20 - 30% reductionminor adverse impact expected

< 30 - 50% reductionmoderate adverse impactsexpected

>50% reductionsubstantial adverse impactsexpected

0

20

40

60

80

100

Ratio ofImpactIs the PSH value at least 80% of its former value?

0

20

40

60

80

100

PSH Before PSH AfterPSH After

80%

*Are balconies the problem?If the PSH ratio of impact is at least 80% of its former value without the balconies on the existing neighboring propety, then the presence of the balcony is the main factor contributing to the relative loss of sunlight.

FAILIf the development fails based on the preceding criteria, there is now an option to set alternative targets if these conditions are met:

Last chance!

Existing planning permission?If planning permission has been granted for the site but for a different massing design, the local authority may allow the VSC and APSH for the permitted scheme to be used as alternative benchmarks. The values of the proposed scheme should either meet or improve on these benchmark values.

Too close for comfort? Use mirror images!Neighbouring buildings sitting too close to the site boundary can be a problem in terms of daylight and sunlight, especially if you’re building on an empty site. In cases like these, VSC and APSH targets for existing buildings can be set using a ‘mirror-image’ building of the same height and size, an equal distance away on the other side of the boundary.

SETTING ALTERNATIVE

TARGETS

Sunlight unlikely

to be affected

EXISTING BUILDINGS

Assessment Criteria - Sunlight

SUNLIGHT

8

Probable Sunlight Hours

Do the windows of the main living room and/or conservatory receive at least 25% PSH throughout the year, with at least 5% PSH being received during the winter period between 21 March and 21 September?

FAIL

No

minimum 5% of APSH

required duringwinter period (WPSH)

minimum 25% of APSH

required duringannual period (APSH)

SUNLIGHTHOURS

PSH

Yes

Yes

Yes

NEW

DEVELOPMENT

New

dev

elopm

ent is with

in 90º due SOUTH of the existing window - CHECK SUN

LIGH

T A

CC

ES

S

New

development is within 90º due NORTH of the existing window - NO NEED TO C

HECK

SU

NLI

GH

T A

CC

ES

S

OrientationDoes the window face within 90° of due south?

Bedrooms& Kitchenssunlightless essential

Living Rooms:sunlight

essential!

No

Views Out

Does the living room have access to outstanding views or amenities that compensate for lack of sunlight?

FAIL

No

START

Room UseIs the room a living room or a conservatory?

No

Testing for sunlightNOT REQUIRED

Yes

PASS

Yes

PROPOSED DEVELOPMENT

Probable Sunlight Hours

2.34 With regards to sunlight, the criteria is based on the Probable Sunlight Hours (PSH), which considers the amount of sun available through out the year and the winter months. For surrounding buildings this analysis is performed on all windows to habitable rooms and conservatories facing within 90° of due south, while for the proposed development any orientation apply, and only main (living rooms) are considered.

2.35 Similar to daylight calculations, the fi rst analysis prior to PSH is the 25º line test. This is explained in more detail in section “25 degree line”.

2.36 The BRE Guide and the BS8206-02 recommend the PSH to be calculated for the whole year (Annual Probable Sunlight Hours, or APSH), and for the winter months (Winter Probable Sunlight Hours, or WPSH).

2.37 Interiors receiving more than 25% of APSH and at least 5% of WPSH (defi ned for these purposes between 21st September and 21st March), receive enough sunlight and the impact will therefore be negligible.

2.38 However, if the available sunlight hours are both, less than the amount described above and less than 0.8 times their former value, either over the whole year or during the winter months, then the occupants of the existing building will notice the loss of sunlight.

SUNLIGHT

SUSTAINABILITY

9

START

Open Space?Does the open space fall under one of the following categories?

LocationIs all or part of the existing open space located on the north, east and/or west of the proposed development?

Sun ContourDoes at least 50% of the area of the open space receive at least 2 hours of sunlight on the 21st of March?

FAIL

PASS

Yes

Yes

Ratio of ImpactIs the area receiving at least two hours of sunlight on the 21st of March at least 80% of its former value?

Yes

Yes

Yes

No

Testing forsunlight

not required

<2 hours of sunlight

>2 hours of sunlight

60%

40%



50%

50%



40%

60%

garden park playground

outdoor swimming/

paddling pools

outdoor

seating areas

public squares monuments

playing field

fountains

0

20

40

60

80

100

Before

% Open Space Area receiving at least

2 hours of sunlight on the 21st of March

After After

80%

No

Sunlight is unlikely to be affected

No

NEW

DEVELOPMENT

EXISTING OPEN SPACES

PASS

Testing forsunlight

not required

No

NoSunlight is unlikely to be affected

START

Open Space?Does the open space fall under one of the following categories?

Sun ContourDoes at least 50% of the area of the open space receive at least 2 hours of sunlight on the 21st of March?

FAIL

Yes

No

Yes



60%

40%



50%

50%



40%

60%

garden park playground

outdoor swimming/

paddling pools

outdoor

seating areas

public squares monuments

playing field

fountains

PROPOSED OPEN SPACES

Sunlight criteria for Open Spaces

2.39 For open spaces, the BRE Guide suggests that at least half of the area should receive two (2) hours of direct sunlight on the Equinox (21st of March) with the proposed development in place (sunlight at an altitude of 10% or less is excluded).

2.40 If the area which can receive at least 2 hours of direct sunlight on the 21st of March is reduced to less than 0.8 times its former value, as a result of a new development, then loss of sunlight is signifi cant.

2.41 This would normally include gardens (usually the main back garden of a house), allotments, parks and playing fi elds, children’s playgrounds, outdoor swimming pools and paddling pools, sitting out areas between non-domestic areas and public squares, and focal points for views.

2.42 Driveways and hard standing for cars, as well as small front gardens are excluded. Normally the shadows from trees and shrubs do not need to be included unless there is a dense belt or group of evergreens planned as a windbreak or for privacy purposes.

2.43 The shadows cast by walls or opaque fences less than 1.5 metres high can be excluded from the calculation.

SUNLIGHT - OVERSHADOWING

SUNLIGHT - OVERSHADOWING

SUSTAINABILITY

11

Project Background

Brief3.1 The Sustainability team at PRP has been commissioned

by Brent Council to undertake a Daylight, Sunlight and Overshadowing Assessment with respect to the Land North of Chippenham Gardens development, located in the London Borough of Brent.

3.2 The aim of the study is to investigate the potential impact of the proposed scheme on daylight and sunlight access to the surrounding neighbouring properties and the daylight/sunlight levels in the proposed building itself.

3.3 The methodology used in this study is based on the numerical tests set out in the 2nd edition of “Site Layout Planning for Daylight and Sunlight: a good practice guide” by PJ Littlefair of the BRE (2011).

The Site3.4 The project is located on a land north of Chippenham

Gardens, in South Kilburn in the London Borough of Brent.

3.5 The proposal is for Land North of Chippenham Gardens development that comprises 52 dwellings situated on a site bounded by streets on all orientations. The site for the proposed development is currently occupied by 5-9 Chippenham Gardens, Kilburn Post Offi ce and 4-26 Stuart Road (even numbers only).

3.6 The site is bounded by some 3storey houses and 4-5 storey fl ats on the North. On the East and West orientations, the site is surrounded by 3 storey terrace houses with commercial spaces at street level. On its southern orientation, the site is surrounded by a 9 storey residential tower.

3.7 The following properties have been identifi ed as potentially being aff ected by the proposed development in terms of daylight and sunlight, due to their proximity to the site:

• Property 1: 21-35 Malvern Road;


• Property 3: John Ratcliff e House;

• Property 4: 1-7 Stuart Road (odd numbers only);

• Property 5: Argo House; and

• Property 6: 209-223 Kilburn Park Road (odd numbers only).

3.8 We will look at these properties in more detail as part of our assessment. Any other properties are unlikely to be aff ected by the proposed development.

Figure 3.1 Project site and the surrounding properties.

The proposal is for Land North of Chippenham Gardens development that comprises 52 dwellings located on a site that forms part of the wider South Kilburn regeneration programme. Redevelopment will involve the demolition of 5-9 Chippenham Gardens, Kilburn Post Offi ce and 4-26 Stuart Road (even numbers only).

Property 4

Property 2Property 3

Proposed building

Chippenham Gardens

Property 5

Property

1

Property 6

Stuart Rd

Kilb

urn

Park

Roa

d

Mal

vern

Roa

d

12

Extent of the Study Area3.9 The study area modelled for this analysis includes the

site and all the immediate surrounding buildings.

3.10 All windows facing the proposed development that were likely to be habitable rooms were considered to be sensitive receptors and therefore have been included in the study (Figure 3.1).

3.11 Facades that did not have windows to habitable rooms, or had windows that did not face the site are not included in the study.

3.12 All other surrounding buildings were excluded from the analysis based on our experience of similar work, as they are far enough from the development to avoid signifi cant negative impacts.

Modelling Assumptions3.13 Access to nearby properties has not been sought or

obtained, however we have made reasonable assumptions as to the geometry of these buildings based on OS map data and aerial photographs for nearby properties. This is normal practice where access to nearby properties is limited.

3.14 Site photographs from Google Street View imagery have been used to establish indicative windows sizes and positions.

3.15 Trees and fences lower than 1.5m have been excluded from the model as per the BRE Guide paragraph 3.3.9 and 3.3.10:

‘trees may be ignored unless they form dense continuous belts...Normally, trees and shrubs need not be included, partly because their shapes are almost impossible to predict, and partly because the dappled shade of a tree is more pleasant than the deep shadow of a building. This applies especially to deciduous trees’.

3.16 Site drawings and OS map data have been provided by PRP Architects LLP.

Analysis and Calculations3.17 The calculations have been undertaken using the

computer program Ecotect Analysis 2011, in which a three dimensional model based on the architectural drawings and the 3D model provided was created.

Preliminary 25-degree line analysis3.18 The identifi ed sensitive receptors were initially

analysed using 25-degree line analysis, which identifi es the façades that are obstructed by the proposed development.

3.19 The results of the analysis showed that the following receptors will not encounter any obstruction from the proposed design and therefore will retain adequate levels of daylight and sunlight even after the proposed development has been put in place, and do not require further analysis:



3.20 The following properties encountered obstructions from the proposed development and will be tested further in accordance with BRE guidelines:

• Property 3: John Ratcliff e House;

• Property 4: 1-7 Stuart Road (odd numbers only);

• Property 5: Argo House; and

• Property 6: 209-223 Kilburn Park Road (odd numbers only).

SUSTAINABILITY

13

Daylight Results Surrounding properties

Property 34.1 Property 3 - John Ratcliff e House, has 2 windows

identifi ed as potentially obstructed by the proposed development (windows FF1 and FF2). They were analysed using Vertical Sky Component (VSC) and Ratio of Impact tests.

4.2 Table 4.1 details results of the analysis. All of the windows analysed in this property will retain good levels of daylight after proposed development is in place.

The results of the analysis show that the surrounding properties experience negligible or minor adverse impacts on daylight access, as a result of the proposed development.

Table 4.1. VSC and ratio of impact results for Property 3.Ratio of

ImpactCompliance Effect

Before After Difference

% % %

FF1 37.8% 29.8% 0.79 PASS Negligible


Property 3, John Ratcliffe House

Window

Reference

Vertical Sky

Component

Pass / FailNegligible / Minor /

Moderate / Substantial




% % %

GF1 31.8% 27.3% 0.86 PASS Negligible


SF1 35.5% 32.5% 0.92 PASS Negligible




GF5 31.4% 24.4% 0.78 FAIL Minor



GF7 30.5% 23.0% 0.76 FAIL Minor



Property 4, Nos 1-7 Stuart Road (odd numbers only)

No.3 Stuart Road

No.5 Stuart Road

No.7 Stuart Road

Vertical Sky

Component



No. 1 Stuart Road

Window

Reference

Property 44.3 Property 4 - 1-7 Stuart Road (odd numbers only),

has 12 windows identifi ed as potentially obstructed by the proposed development. These windows are located on the ground, fi rst and second fl oors of house numbers 1-7 Stuart Road (odd numbers only). Daylight levels at these windows was analysed using Vertical Sky Component (VSC) and Ratio of Impact tests.

4.4 Out of the 12 windows analysed, 10 windows will retain adequate levels of daylight after the proposed building is in place. The results are detailed in Table 4.2.

4.5 Only two windows have VSCs’ and ratio of impact below BRE criteria. These two windows are located on the ground fl oor of house No.5 & No.7 Stuart Road. Both windows GF5 and GF7 experience minor adverse impact. As no access was gained to these houses no further analysis was undertaken and the impact is based on the ratio of the VSC results. The number of these windows is referenced in Figure A.1 in Appendix A.

14

Property 54.6 There are 8 windows in Property 5 - Argo House that

face the proposed development. They were tested for VSC levels in existing and proposed conditions. Table 4.3 details results of the analysis.

4.7 Out of the 8 windows analysed, 5 windows will retain adequate levels of daylight after proposed building is in place.

4.8 Windows FF1 to FF3 experience minor adverse impact. These windows are located on the fi rst fl oor of this property. As this property is under construction the drawings submitted as part of the planning application were checked, this in order to understand the use of these windows. From the fi rst fl oor plan is clearly marked that these windows are specifi ed to be obscured glass, due to overlooking issues. All these three windows are secondary windows to a room that is served by a main window with a diff erent orientation and not facing the proposed development. As these windows are secondary windows we consider that the rooms served by these windows will maintain adequate levels of daylight, even with the proposed development in place. The number of these windows is referenced in Figure A.2 in Appendix A.

4.9 All the rooms served by the windows analysed in this property will retain good levels of daylight after proposed development is in place.




% % %

F1 32.5% 23.5% 0.72 FAIL

F2 33.1% 23.6% 0.71 FAIL

F3 33.6% 26.6% 0.79 FAIL Minor

F1 36.1% 28.2% 0.78

F2 36.4% 28.5% 0.78

F3 36.6% 31.0% 0.85 PASS Negligible



Property 5, Argo House

Window

Reference

Vertical Sky

Component



Minor

Minor

PASS

PASS

Negligible

Negligible

Property 64.10 There are 64 windows serving 32 rooms in the houses

named as Property 6 - 209-223 Kilburn Park Road

(odd numbers only) that are facing the proposed development. They were tested for VSC levels in existing and proposed conditions. Table 4.4 details the results of the analysis.

4.11 Out of the 32 rooms analysed, 31 rooms (61 windows)will retain adequate levels of daylight after proposed building is in place.

4.12 The ground fl oor room in 219 Kilburn Park Road, which is served by windows GF1 to GF3 experience minor adverse impact. This represent a small percentage (only 3% of the rooms analysed), which is consider acceptable, due to the minor impact caused.

4.13 The vast majority of the rooms served by the windows analysed in this property will retain good levels of daylight after proposed development is in place.

Summary of Results4.14 The results of the assessment show that a majority of

the windows analysed in the surrounding properties will experience negligible impacts on their daylight access as a result of the proposed development.

4.15 A total of 2 nos.windows in Property 4, 3nos.windows in Property 5 and 3 nos.windows in Property 6 will receive minor adverse impacts, as a result of the proposed development. The aff ected windows are identifi ed and illustrated in the images provided in Appendix A.

SUSTAINABILITY

15

Table 4.4. VSC and ratio of impact results for Property 6.

Ratio of



% % %



















GF3 27.8% 21.6% 0.78 FAIL Minor







GF2 31.6% 24.5% 0.78 FAIL Minor

GF3 28.3% 21.4% 0.76 FAIL Minor



FF3 30.0% 23.8% 0.80 FAIL Minor




GF2 31.7% 23.5% 0.74 FAIL Minor

GF3 27.5% 20.5% 0.75 FAIL Minor


FF2 33.4% 26.0% 0.78 FAIL Minor

FF3 29.4% 23.0% 0.78 FAIL Minor



Property 6, Nos 209-223 Kilburn Park Road (odd numbers only)

Nos 209 Kilburn Park Road





Vertical Sky

ComponentWindow

ReferenceNegligible / Minor /

Moderate / SubstantialPass / Fail

GF1 29.0% 22.2% 0.77 FAIL Minor

GF2 31.7% 23.3% 0.74 FAIL Minor

GF3 28.0% 21.7% 0.78 FAIL Minor


FF2 33.4% 25.7% 0.77 FAIL Minor




GF1 30.2% 23.2% 0.77 FAIL Minor

GF2 31.7% 24.2% 0.76 FAIL Minor



FF2 33.3% 26.3% 0.79 FAIL Minor




GF1 29.5% 22.5% 0.76 FAIL Minor

GF2 31.5% 24.4% 0.77 FAIL Minor


FF1 31.6% 25.0% 0.79 FAIL Minor








PASS

PASS

PASS

PASS

FAIL

PASSPASS

PASS

PASS

PASS

PASS

PASS

PASS

PASS

PASS

PASS

PASS

Negligible

Negligible

Negligible

Negligible

Minor

NegligibleNegligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

16

Daylight ResultsProposed development

Analysis assumptions4.16 Where a room is served by more than one window,

Average Daylight Factor (ADF) calculations are made in relation to each window and the individual results added together to provide the true ADF for that room.

4.17 With regard to the ADF calculations for the proposed accommodation, the following assumptions have been made with regard to the various elements that together are computed to produce the ADF value;

• Glazing transmittance - 0.68 for the double glazing (BRE default reading);

• Interior surface refl ectance: Walls - 0.6, Ceiling - 0.8 and Floor - 0.4;

• Refl ectance beneath reference working plane (0.85m) - 0.4 (refl ectance of the fl oor)

Average Daylight Factor (ADF) results4.18 The proposed development comprises 16 diff erent

unit types. A sample set of units which represent the worst case scenario across each unit type were chosen on the ground, fi rst and third fl oors and tested for their daylight availability.

4.19 ADF results are summarised in Table 4.5. Detailed tables for the ADF analysis are located in Appendix B. of this report.

4.20 The results show that rooms failing the ADF analysis are mainly kitchens. Based on our experience of similar work this is due to the window to fl oor ratio rather than low Vertical Sky Components (VSC) values. Therefore, the rooms that are failing in the worst case scenario will continue failing on the top fl oors as well.

4.21 According to the results of the analysis of worst case scenario of each type, we conclude that there are 26% of the rooms (44 out of total 169 rooms), that will have ADF values below the minimum BRE threshold. The rest 74% of the rooms will fully comply with BRE requirements.

4.22 As the majority of the rooms will achieve good levels of daylight this is considered acceptable due to the increased density and urban context of the site.

The results of the analysis show that the majority of the rooms analysed in the proposed development will experience good levels of daylight, in excess to the BRE requirements.

Table 4.5. ADF results summary for the proposed development.

GF FF 2F 3F 4F 5F

24 33 33 33 30 16

Pass 15 25 25 25 23 12

Fail 9 8 8 8 7 4

Total number of rooms

FLOOR

Compliance

ADF analysis results

SUSTAINABILITY

17

Sunlight ResultsSurrounding properties

Property 45.1 Property 4, 1-7 Stuart Road (odd numbers only),

has 12 south-facing windows that face the proposed development. There windows were analysed for Probable Sunlight Hours (APSH and WPSH) and results are detailed in Tables 5.1. All the windows analysed in the surrounding Property 4 receive good levels of sunlight with the proposed development in place.

The results of the analysis show that most of the surrounding properties assessed experience negligible impacts on sunlight access, as a result of the proposed development.

Table 5.1. PSH results for the Property 4.

APSH

Before

APSH

After

APSH

Difference

WPSH

Before

WPSH

After

WPSH

DifferenceCompliance

% % % % % % Pass / Fail

GF1 76.9% 66.8% 86.9% 30.9% 21.2% 68.4% PASS

FF1 81.3% 72.6% 89.3% 34.5% 25.9% 75.0% PASS

SF1 89.7% 81.7% 91.1% 38.2% 30.2% 79.1% PASS

GF3 63.4% 54.8% 86.3% 26.9% 18.3% 68.0% PASS

FF3 66.3% 58.9% 88.9% 29.8% 22.4% 75.2% PASS

SF3 73.3% 66.6% 90.8% 32.6% 25.8% 79.2% PASS

GF5 81.6% 68.8% 84.4% 28.6% 16.7% 58.3% PASS

FF5 87.2% 75.1% 86.2% 33.4% 21.6% 64.6% PASS

SF5 92.3% 80.8% 87.6% 38.3% 26.9% 70.1% PASS

GF7 79.4% 65.5% 82.6% 26.8% 14.0% 52.1% PASS

FF7 85.6% 72.4% 84.6% 32.1% 18.9% 59.0% PASS

SF7 91.4% 78.8% 86.2% 37.4% 24.8% 66.4% PASS

Window

Reference

Property 4, Nos 1-7 Stuart Road (odd numbers only)

No. 1 Stuart Road

No.3 Stuart Road

No.5 Stuart Road

No.7 Stuart Road

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible /

Minor /

Moderate /

Substantial

18

Property 55.2 Property 5, Argo House has 8 south-facing windows

facing the proposed development. Windows to this property were analysed for Probable Sunlight Hours (APSH and WPSH) and results are detailed in Tables 5.2. Most of the windows analysed in Property 5 receive good levels of sunlight after the proposed development is in place.

5.3 Only 1 window located on the ground fl oor is impacted by the proposed development. However, the loss of sunlight to this property can be considered minor as the values are less than 1% outside the requirements.

Table 5.2. PSH results for the Property 5.

APSH

Before

APSH

After

APSH

Difference

WPSH

Before

WPSH

After

WPSH


% % % % % % Pass / Fail

GF1 82.7% 65.8% 79.6% 30.9% 15.8% 51.2% FAIL

GF2 83.3% 66.8% 80.2% 31.5% 17.4% 55.1% PASS

GF3 83.6% 71.4% 85.4% 31.9% 23.7% 74.3% PASS

FF1 90.9% 75.4% 82.9% 38.6% 23.2% 60.2% PASS

FF2 90.7% 76.3% 84.0% 38.4% 24.2% 63.0% PASS

FF3 90.1% 80.2% 89.0% 37.7% 29.1% 77.2% PASS

SF1 94.7% 85.8% 90.6% 42.4% 33.5% 79.1% PASS

SF2 93.7% 87.3% 93.1% 41.3% 35.0% 84.8% PASS

Property 5, Argo House

Window

Reference

Minor

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible /

Minor /

Moderate /

Substantial

Property 6

5.4 Property 6, 209-223 Kilburn Park Road (odd

numbers only) has 16 south-east facing windows, distributed on the ground and fi rst fl oors of 8 terrace houses, facing the proposed development. Windows to these properties were analysed for Probable Sunlight Hours (APSH and WPSH) and results are detailed in Table 5.3.

5.5 All windows located both on the ground and fi rst fl oors of the 3 properties (219-223 Kilburn Park Road) receive adequate levels of sunlight with the proposed development in place.

SUSTAINABILITY

19

Table 5.3. PSH results for Property 6

APSH

Before

APSH

After

APSH

Difference

WPSH

Before

WPSH

After

WPSH


% % % % % % Pass / Fail

GF3 33.2% 30.1% 72.4% 7.3% 6.8% 92.0% FAIL

FF3 38.4% 23.4% 78.3% 8.8% 5.5% 62.8% FAIL

GF3 33.8% 24.4% 72.4% 8.1% 6.5% 79.4% FAIL

FF3 37.4% 29.3% 78.3% 9.6% 7.8% 81.4% PASS

GF3 30.4% 21.2% 69.8% 6.9% 6.1% 87.7% FAIL

FF3 34.5% 24.9% 72.1% 8.3% 7.4% 88.4% FAIL

GF3 32.6% 23.7% 72.8% 7.4% 7.0% 94.4% FAIL

FF3 35.8% 26.4% 73.7% 9.0% 8.5% 94.8% PASS

GF3 31.4% 22.7% 72.4% 6.2% 6.2% 100.0% FAIL

FF3 34.8% 25.8% 74.1% 7.6% 7.6% 100.4% PASS

GF3 33.2% 26.8% 80.6% 7.0% 7.0% 100.0% PASS

FF3 35.6% 28.7% 80.5% 8.4% 8.4% 100.3% PASS

GF3 32.2% 28.0% 87.0% 6.7% 6.7% 100.0% PASS

FF3 37.2% 33.0% 88.9% 8.0% 8.0% 100.0% PASS

GF3 35.6% 33.5% 94.1% 8.8% 8.8% 100.0% PASS

FF3 38.7% 36.4% 94.1% 9.7% 9.7% 100.0% PASS

Window

Reference


Property 6, Nos 209-223 Kilburn Park Road (odd numbers only)








Minor

Moderate

Minor

Negligible

Minor

Minor

Minor

Negligible

Minor

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible

Negligible /

Minor /

Moderate /

Substantial

Table 5.4. PSH results for the surrounding properties

Number of

windows PASS

Negligible

impactMinor Impact

Moderate

impact

Property 4 12 12 0 -

Property 5 8 7 1 -

Property 6 16 9 6 1

Property name

Total number

of windows

analysed

Number of windows FAIL

5.6 Most of the windows located on the ground fl oors of 4 properties nos. 211- 217 Kilburn Park Road (odd numbers only) receive minor impacts on their ground fl oor windows from the proposed development in place. However, the loss of sunlight to this property can be considered minor as all rooms served by these windows have 1-2 other additional windows that are orientated away from the proposed development. Therefore, the rooms should continue to receive adequate levels of sunlight.

5.7 Similarly, the loss of sunlight to the ground and fi rst fl oor windows of property no. 209 Kilburn Park Road will not be adverse, as these rooms are served by additional windows that are orientated away from the proposed development.

Summary of Results5.8 The results of our analysis show that a majority of

the windows that face the proposed development analysed achieve good levels of sunlight access as a result of the proposed development, during the whole year and winter months.

5.9 Some of the windows located on the properties 209-223 Kilburn Park Road (odd numbers only) , receive minor -moderate impacts. However, all rooms served by these windows have 1-2 other additional windows that are orientated away from the proposed development. Therefore, the rooms should continue to receive adequate levels of sunlight.

20

Sunlight Results Proposed development

Sunlight analysis5.10 By reference to paragraph 3.1.7 of the BRE guide, the

guidance seeks to ensure that the majority of main (living) rooms should face due south for maximum sunlight access.

5.11 All the south, east, west facing windows within the proposed development were tested to meet the BRE criteria for sunlight, while north facing windows are not considered to meet the criteria. A summary of the sunlight performance of the proposed development (annual probable sunlight hours results)is shown in Table 5.5. Detailed tabulated results can be found in Appendix B of this report.

Majority of the units have the sunlight availability to the proposed accommodation in accordance with BRE’s criteria for sunlight.

Summary of Results5.12 The proposed development has 52 main living rooms,

most of the rooms have windows facing due south. They were all analysed in terms of Probable Sunlight Hours.

5.13 A majority of the living rooms tested (90.3%) fully comply with the minimum BRE threshold for annual and winter probable sunlight hours. A small proportion (9.6%) of the living rooms (5 rooms) do not meet the BRE requirements for the Probable Sunlight Hours.

5.14 Limited levels of sunlight is mainly recorded in the living rooms that are located along the courtyard elevations.

5.15 Sunlight availability to the most of the rooms of the proposed development is in accordance with BRE’s criterion for sunlight.

Table 5.5. PSH results for the Proposed development.

GF FF 2F 3F 4F 5F

7 11 11 10 8 5

Pass 6 9 9 10 8 5

Fail 1 2 2 0 0 0

FLOOR

Total number of main

Compliance

PSH analysis results

SUSTAINABILITY

21

Overshadowing Results

Open Spaces6.1 Some of the neighbouring properties identifi ed in the

report earlier House Nos.1-9 Stuart Road (odd numbers only) and Argo House have gardens and open spaces that are located within 90 degree due north of the proposed development, and will have to be analysed to assess any potential risks of overshadowing from the proposed development.

6.2 The assessment is also carried out on the public highway (open space) which exists adjacent to the proposed development. Open spaces to the south of the development and those too far away to be impacted have not been analysed.

The results of the analysis show that most of the open spaces and gardens associated with the neighbouring properties analysed will receive good levels sunlight. Only one garden of the eight tested spaces receives a minor impact from the proposed development.

6.3 Low fences (<1.5m), trees and small front gardens have not been included in the study as per the BRE methodology. However, any fences that are higher than 1.5m are included within the assessment.

6.4 An overshadowing analysis was carried out on 7 open spaces. These are identifi ed in Figure 6.1 and described below:

• Open Space 1SH: Rear garden of No. 1 Stuart Road

• Open Space 3SH: Rear garden of No.3 Stuart Road




• Open Space 1AH: Open Space of Argo House

• Public Highway (open space): Existing open space adjacent to the development

Figure 6.1. Overshadowing map every 60 minutes (grey areas represent areas in shadow)

Public Highway

(open space)

1SR3SR 5SR

7SR

9SR

1AH

Stuart Road

Stuart Road

Argo House

Proposed

Courtyard

22

House

No. 1

(Existing)

House

No. 1

(Proposed)

House No.

3

(Existing)

House

No. 3

(Proposed)

House

No.5

(Existing)

House

No. 5

(Proposed)

House

No.7

(Existing)

House

No. 7

(Proposed)

House

No.9

(Existing)

House

No. 9

(Proposed)

<2 67.7% 67.7% 73.2% 89.2% 97.5% 99.9% 63.7% 80.6% 55.6% 55.6%

>2 32.3% 32.3% 26.8% 10.8% 2.5% 0.1% 36.3% 19.4% 44.4% 44.4%

Difference

Compliance

Hours

House Nos. 1-9 Stuart Road (odd numbers only)

PASS PASS PASS FAIL (Marginal) PASS

100% 82.1% 98% 79.1% 100%

Sunlight criteria for Open Spaces6.5 Figure 6.1 illustrates the overshadowing cast on the

open spaces in time steps of one hour during the Equinox. In this map, areas with good solar access are displayed in lighter colours while overshadowed areas are shown in darker tones.

6.6 The BRE Guide suggests that all open spaces should have minimum 2 hours of sun on at least 50% of the site on the 21st of March (Equinox), to be considered adequately sunlight throughout the year.

6.7 The results of the analysis show that most of the open spaces and gardens associated with the neighbouring properties comply with the BRE Guidelines for solar access (Tables 6.1-6.3).

6.8 Table 6.1 shows the results of the open spaces associated with House Nos.1-9 located along Stuart Road (odd numbers only).

6.9 Most of these spaces are overshadowed in both the existing and proposed conditions, mainly due to the presence of a high fence along the boundary of the gardens. The reduction in sunlight levels within most of these gardens and open spaces due to the proposed development, are within the limits set by the BRE. One open space which is associated with the garden of House No. 7 along Stuart Road has a marginal impact from the proposed development.

6.10 However, the loss of sunlight to this garden can be considered minor as the values are less than 1% outside the requirements.

6.11 Table 6.2 shows the results of the open spaces associated with Argo House. Table 6.3 shows the results of the open spaces associated with the public highway (open space) located adjacent to the proposed development. Both these spaces receive adequate levels of sunlight with the proposed development in place.

HoursArgo House

(Existing)

Argo House

(Proposed)

<2 0.0% 38.3%

>2 100.0% 61.7%

Compliance PASS

HoursAdjacent public

highway (Existing)

Adjacent public

highway (proposed)

<2 3.1% 0.0%

>2 96.9% 100.0%

Compliance PASS

Table 6.1. Overshadowing results for surrounding amenities

Table 6.2. Overshadowing results for Argo House amenity

Table 6.3. Overshadowing results for adjacent public highway (open space)

SUSTAINABILITY

23

Conclusion7.1 The aim of the study is to investigate the potential

impact of the proposed scheme on daylight and sunlight access compared to what is currently being experienced by the surrounding adjacent properties.

7.2 The methodology used in this study is based on the guidance provided in the 2nd edition of Building Research Establishment (BRE) entitled: “Site Layout Planning for Daylight and Sunlight: a good practice guide” by PJ Littlefair (2011).

7.3 The results of the daylight, sunlight and overshadowing assessment concludes that the proposed development will have a negligible- minor adverse impact on the surrounding properties and their associated amenity areas.

7.4 A majority of dwellings within the proposed development will receive adequate levels of daylight and sunlight in line with the recommendations provided by the BRE Guide.

SUSTAINABILITY

25

Appendix A - Window numbering Windows analysed in Surrounding Properties

Figure A.1. Property 4, 1-7 Stuart Road, Elevation facing the

application site

Figure A.3. Property 6, 209 -215 Killburn Park Road,

Elevation facing the application site

Figure A.2. Property 5, Argo House, Elevation facing the

application site

Figure A.4. Property 6, 217 - 223, Killburn Park Road,

Elevation facing the application site

FF1FF1FF2FF2

GF1GF1

FF1FF1

SF1SF1 SF1SF1 SF1SF1SF1SF1 SF1SF1 SF1SF1 SF1SF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF1GF1

FF1FF1

GF2GF2

FF2FF2

SF2SF2 SF2SF2 SF2SF2 SF2SF2SF2SF2 SF2SF2 SF2SF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF2GF2

FF2FF2

GF3GF3

FF3FF3

GF3GF3

FF3FF3

GF3GF3

FF3FF3

GF3GF3

FF3FF3

GF3GF3

FF3FF3

GF3GF3

FF3FF3FF3FF3

FF1FF1 FF2FF2FF3FF3

2F12F1 2F22F22F32F3

3F13F13F23F2

Figure A.5. Property 3, John Ratcliff e House, Elevation facing

the application site

GF1GF1 GF3GF3GF5GF5 GF7GF7

FF1FF1 FF3FF3FF5FF5 FF7FF7

SF1SF1 SF3SF3SF5SF5 SF7SF7

1 35 7

SF1SF1

GF3GF3

209 211 213 215 217 219 221 223

26

Windows and rooms analysed in Proposed building

Figure A.3. Proposed Ground fl oor plan

DR

BI

BUSSHELTER

Shared Entrance

Entrance

Individual Entrance

In

Individual Entrance

Individual Entrance Individual EntranceIndividual Entrance

Shared Entrance (Private)

Shared Entrance (Affordable)

98.72 m²Plot 0.1

Unit Type 13B6P

67.74 m²Plot 0.2

Unit Type 21B2P WCA

53.31 m²Ancillary

PlantHeat & Power

69.42 m²Plot 0.3

Unit Type 31B2P WCA

56.62 m²Plot 0.4

Unit Type 41B2P

61.36 m²Plot 0.5

Unit Type 51B2P WCA

111.06 m²Plot 0.6

Unit Type 63B5P WCA

111.06 m²Plot 0.7

Unit Type 63B5P WCA

22.39 m²Ancillary

StorageBikes

27.49 m²Ancillary

StorageBikes

25.29 m²Ancillary

StorageRefuse

15.31 m²Ancillary

StorageRefuse

rance (Private)

Type 1

Type 2

Type 3 Type 4

Type 5

Type 6Type 6a

12

11

09

18

10

1614 15 19 17

20

21

28

27

22

23

2425

2633

3031

32

29

34

35

01

07

08

020304

05

06

13

Figure A.6. Proposed Ground fl oor plan

SUSTAINABILITY

27

Figure A.3. Proposed Ground fl oor planDR

DR

BI

BUSSHELTER

98.72 m²Plot 1.1

Unit Type 73B6P

18.18 m²Plot 1.1

BalconyAmenity

54.65 m²Plot 1.2

Unit Type 81B2P

11.13 m²Plot 1.2

BalconyAmenity

29.29 m²Plot 1.3

BalconyAmenity

59.04 m²Plot 1.3

Unit Type 91B2P

73.03 m²Plot 1.4

Unit Type 102B4P

13.21 m²Plot 1.4

BalconyAmenity

83.61 m²Plot 1.5

Unit Type 112B4P

6.63 m²Plot 1.5

BalconyAmenity

33.02 m²Plot 1.6

BalconyAmenity

80.42 m²Plot 1.6

Unit Type 122B4P

77.96 m²Plot 1.7

Unit Type 132B4P

12.12 m²Plot 1.7

BalconyAmenity

50.30 m²Plot 1.8

Unit Type 14a1B2P

10.51 m²Plot 1.8

BalconyAmenity

51.34 m²Plot 1.9

Unit Type 15a1B2P

11.12 m²Plot 1.9

BalconyAmenity

22.48 m²Plot 1.1

BalconyAmenity

11.93 m²Plot 1.5

BalconyAmenity

50.30 m²Plot 1.11

Unit Type 14a1B2P

11.15 m²Plot 1.11

BalconyAmenity

51.34 m²Plot 1.10

Unit Type 15a1B2P

9.08 m²Plot 1.10

BalconyAmenity

Type 7

Type 8

Type 9

Type 10

Type 14a

Type 14

Type 11

Type 12

Type 13

Type 15

Type 15a

16

15

13 17

28

14

19 20

21 22

18

23 29

25

24

2730 26

31

32

33

34

35

42

38

3940

4143

4445

46

47

37

36

01

02

09

08

030405

06

07

11

12

10

DR

.03 m²ot 3.4

Type 102B4P

80.42 m²Plot 3.6

Unit Type 122B4P

77.96 m²Plot 3.7

Unit Type 132B4P

50.30 m²Plot 3.8

Unit Type 14a1B2P

51.34 m²Plot 3.9

Unit Type 15a1B2P

103.74 m²Plot 3.10

Unit Type 163B6P

83.61 m²Plot 3.5

Unit Type 112B4P

Type 16

0702

03

04

01

05

06

Figure A.7. Proposed First fl oor plan

Figure A.7. Proposed Third fl oor plan

SUSTAINABILITY

29

Appendix B - Tabulated results Tabulated results of daylight and sunlight calculations for the worst case scenario proposed development.

Unit

Height (m)Depth

(m)Width (m) # Type

Height

(m)Width (m) Head 9m) Proposal Compliance APSH WPSH

Complianc

e

01 5 0.40 0.84 1.42 6.37

02 3 0.40 1.74 1.42 30.00

03 5 0.40 0.84 1.42 30.00

04 5 0.40 0.84 1.42 29.00

1 Up 1.63 1.74 2.48 15.00

1 Low 0.35 1.74 N/A 15.00

1 Up 1.63 1.74 2.48 20.90

1 Low 0.35 1.74 N/A 20.90

1 Up 1.63 1.74 2.48 6.84

1 Low 0.35 1.74 N/A 6.84

2 Up 1.63 0.84 2.48 6.81

2 Low 0.35 0.84 N/A 6.81

1 Up 1.63 1.74 2.48 16.00

1 Low 0.35 1.74 N/A 16.00

4 Up 1.63 2.71 2.48 14.50

4 Low 0.35 2.71 N/A 14.50

2 Up 1.63 0.84 2.48 19.67

2 Low 0.35 0.84 N/A 19.67

1 Up 1.63 1.74 2.48 16.58

1 Low 0.35 1.74 N/A 16.58

1 Up 1.63 1.74 2.48 18.60

1 Low 0.35 1.74 N/A 18.60

2 Up 1.63 0.84 2.48 15.83

2 Low 0.35 0.84 N/A 15.83

1 Up 1.63 1.74 2.48 15.44

1 Low 0.35 1.74 N/A 15.44

4 Up 1.63 2.71 2.48 34.00

4 Low 0.35 2.71 N/A 34.00

1 Up 1.63 1.74 2.48 18.15

1 Low 0.35 1.74 N/A 18.15

4 Up 1.63 2.71 2.48 17.13

4 Low 0.35 2.71 N/A 17.13

1 Up 1.63 1.74 2.48 11.00

1 Low 0.35 1.74 N/A 11.30

1 Up 1.63 1.74 2.48 18.03

1 Low 0.35 1.74 N/A 18.03

2 Up 1.63 0.84 2.48 14.97

2 Low 0.35 0.84 N/A 14.97

1 Up 1.63 1.74 2.48 14.44

1 Low 0.35 1.74 N/A 14.44

4 Up 1.63 2.71 2.48 20.16

4 Low 0.35 2.71 N/A 20.16

2 Up 1.63 0.84 2.48 18.74

2 Low 0.35 0.84 N/A 18.74

2 Up 1.63 0.84 2.48 17.74

2 Low 0.35 0.84 N/A 17.74

2 Up 1.63 0.84 2.48 14.26

2 Low 0.35 0.84 N/A 14.26

1 Up 1.63 1.74 2.48 16.84

1 Low 0.35 1.74 N/A 16.84

2 Up 1.63 0.84 2.48 15.38

2 Low 0.35 0.84 N/A 15.38

Type

GROUND FLOOR

25

26

27

28

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

Room PSH

Name Type

Surface AreaCharacteristi

csDimensions

Room ADF Room Window

VSC

Proposal

(%)

0.59 FailGFK01 K 2.50 3.60 4.50

1.74 PassGFL02 L 2.50 3.60 4.80 37% 12% Pass

GFB03 B 2.50 3.65 3.30 2.07 Pass

GFB04 B 2.50 3.60 3.35 1.18 Pass

GFB05 B 2.50 3.60 3.35 0.57 Fail

GFK06 K 2.50 5.87 2.30 1.52 Fail

GFL07 L 2.50 5.00 3.31 4.20 Pass 56% 16% Pass

GFB08 B 2.50 3.20 4.30 1.74 Pass

GFK09 K 2.50 8.20 3.58 1.28 Fail 62% 24% Pass

GFB10 B 3.26 4.35 4.10 Pass

GFK11 K 2.50 6.04 5.34

2.50

59% 19% Pass2.30 Pass

GFB12 B 2.50 4.74 2.75 1.33 Pass

GFK13 K 2.50 7.51 3.39 1.05 Fail 47% 18% Pass

GFB14 B 2.50 4.92 2.99 0.69 Fail

GFK15 K 2.50 4.62 3.40 1.52 Fail

GFL16 L 2.50 4.36 3.61 4.11 Pass 43% 16% Pass

GFB17 B 2.50 3.55 2.40 0.99 Pass

GFB18 B 2.50 4.82 3.02 1.56 Pass

Type 1

Type 2

Type 3

Type 4

Type 5

Type 6

GFB19 B 2.50 4.84 3.03 0.71 Fail

Table A1. ADF and PSH results for the Ground fl oor of the proposed development.

30

Unit

Height (m)Depth

(m)Width (m) # Type

Height


Complianc

e

24 9 7 1

15 6

01 5 0.40 0.84 1.42 8.70

2 Up 1.63 0.84 2.48 8.00

2 Low 0.35 0.84 N/A 8.00

03 3 0.40 1.74 1.42 34.00

2 Up 1.63 0.84 2.48 34.50

2 Low 0.35 0.84 N/A 34.50

2 Up 1.63 0.84 2.48 34.70

2 Low 0.35 0.84 N/A 34.70

4 Up 1.63 2.71 2.48 18.78

4 Low 0.35 2.71 N/A 18.78

1 Up 1.63 1.74 2.48 22.70

1 Low 0.35 1.74 N/A 22.70

1 Up 1.63 1.74 2.48 19.50

1 Low 0.35 1.74 N/A 19.50

1 Up 1.63 1.74 2.48 8.00

1 Low 0.35 1.74 N/A 8.00

1 Up 1.63 1.74 2.48 20.72

1 Low 0.35 1.74 N/A 20.72

4 Up 1.63 2.71 2.48 16.80

4 Low 0.35 2.71 N/A 16.80

1 Up 1.63 1.74 2.48 18.95

1 Low 0.35 1.74 N/A 18.95

1 Up 1.63 1.74 2.48 18.17

1 Low 0.35 1.74 N/A 18.17

1 Up 1.63 1.74 2.48 19.23

1 Low 0.35 1.74 N/A 19.23

2 Up 1.63 0.84 2.48 18.11

2 Low 0.35 0.84 N/A 18.11

1 Up 1.63 1.74 2.48 14.81

1 Low 0.35 1.74 N/A 14.81

4 Up 1.63 2.71 2.48 12.60

4 Low 0.35 2.71 N/A 12.60

2 Up 1.63 0.84 2.48 10.23

2 Low 0.35 0.84 N/A 10.23

2 Up 1.63 0.84 2.48 13.53

2 Low 0.35 0.84 N/A 13.53

4 Up 1.63 2.71 2.48 6.41

4 Low 0.35 2.71 N/A 6.41

1 Up 1.63 1.74 2.48 19.61

1 Low 0.35 1.74 N/A 19.61

1 Up 1.63 1.74 2.48 19.31

1 Low 0.35 1.74 N/A 19.31

4 Up 1.63 2.71 2.48 13.37

4 Low 0.35 2.71 N/A 13.37

1 Up 1.63 1.74 2.48 10.93

1 Low 0.35 1.74 N/A 10.93

1 Up 1.63 1.74 2.48 13.11

1 Low 0.35 1.74 N/A 13.11

Type

FIRST FLOOR

21

22

23

24

25

12

13

14

15

16

17

18

19

20

02

04

05

06

07

08

09

10

11

FFB42 B 2.50 3.56 3.40 1.56 Pass

1.40 PassFFB41 B 2.50 3.28 3.78

55% 23% Pass

Type 10

Type 11

FFK40 K 2.50 7.60 4.48 1.13 Fail

FFB39 B 2.50 3.11 3.89 1.96 Pass

25% 9% Pass

FFB38 B 2.50 2.75 4.33 1.97 Pass

FFL37 L 2.50 3.24 4.65 1.53 Pass

Type 7

Type 8

Type 9

FFK36 K 2.50 2.83 4.22 1.43 Fail

FFB35 B 2.50 3.58 3.34 2.41 Pass

62% 21% Pass

FFK33 K 2.50 3.58 3.34 1.90 Fail

FFL34 L 2.50 4.51 3.57 3.68 Pass

29% 12% Pass

FFB32 B 2.50 4.32 2.91 1.86 Pass

FFL31 L 2.50 3.47 3.70 2.69 Pass

FFK30 K 2.50 3.56 3.02 2.23 Pass

FFB29 B 2.50 3.65 3.29 1.25 Pass

FFB28 B 2.50 3.58 3.34 1.99 Pass

41% 15% Pass

FFB27 B 2.50 3.58 3.34 2.20 Pass

FFL26 L 2.50 4.51 3.57 4.79 Pass

FFK25 K 2.50 4.20 3.38 0.89 Fail

Room PSH

Name Type


csDimensions


VSC

Proposal

(%)

1 Up 1.63 1.74 2.48 17.09

1 Low 0.35 1.74 N/A 17.09

2 Up 1.63 0.84 2.48 26.50

2 Low 0.35 0.84 N/A 26.50

2 Up 1.63 0.84 2.48 27.99

2 Low 0.35 0.84 N/A 27.99

1 Up 1.63 1.74 2.48 17.64

1 Low 0.35 1.74 N/A 17.64

2 Up 1.63 0.84 2.48 23.90

2 Low 0.35 0.84 N/A 23.90

1 Up 1.63 1.74 2.48 13.24

1 Low 0.35 1.74 N/A 13.24

1 Up 1.63 1.74 2.48 14.38

1 Low 0.35 1.74 N/A 14.38

29

30

31

32

33

Type 6a

GFK20 K 2.50 4.62 3.40 1.68 Fail

GFL21 L 2.50 4.36 3.61 3.52 Pass 19% 1% Fail

GFB22 B 2.50 3.55 2.40 1.37 Pass

GFB23 B 2.50 4.82 3.02 1.36 Pass34

1.41 PassGFB24 B 2.50 4.84 3.03 35

Table A2. ADF and PSH results for the First fl oor of the proposed development.

SUSTAINABILITY

31

Unit

Height (m)Depth

(m)Width (m) # Type

Height


Complianc

e

33 8 11 2

25 9

1 Up 1.63 1.74 2.48 19.66

1 Low 0.35 1.74 N/A 19.66

2 Up 1.63 0.84 2.48 36.87

2 Low 0.35 0.84 N/A 36.87

2 Up 1.63 0.84 2.48 37.41

2 Low 0.35 0.84 N/A 37.41

1 Up 1.63 1.74 2.48 20.40

1 Low 0.35 1.74 N/A 20.40

1 Up 1.63 1.74 2.48 16.72

1 Low 0.35 1.74 N/A 16.72

1 Up 1.63 1.74 2.48 18.10

1 Low 0.35 1.74 N/A 18.10

1 Up 1.63 1.74 2.48 35.68

1 Low 0.35 1.74 N/A 35.68

Type

THIRD FLOOR

01

02

03

04Type 16

05

06

073FB62 B 2.50 3.76 3.42 2.94 Pass

3FB61 B 2.50 4.20 2.80 1.90 Pass

26% 5% Pass

3FB60 B 2.50 4.20 2.80 1.81 Pass

3FL59 L 2.50 3.76 4.93 3.73 Pass

3FK58 K 2.50 3.96 3.60 1.77 Fail

Room PSH

Name Type


csDimensions


VSC

Proposal

(%)

Unit

Height (m)Depth

(m)Width (m) # Type

Height


Complianc

e

4 Up 1.63 2.71 2.48 20.69

4 Low 0.35 2.71 N/A 20.69

2 Up 1.63 0.84 2.48 21.59

2 Low 0.35 0.84 N/A 21.59

2 Up 1.63 0.84 2.48 20.71

2 Low 0.35 0.84 N/A 20.71

1 Up 1.63 1.74 2.48 17.90

1 Low 0.35 1.74 N/A 17.90

1 Up 1.63 1.74 2.48 16.11

1 Low 0.35 1.74 N/A 16.11

1 Up 1.63 1.74 2.48 27.81

1 Low 0.35 1.74 N/A 27.81

2 Up 1.63 0.84 2.48 29.90

2 Low 0.35 0.84 N/A 29.90

2 Up 1.63 0.84 2.48 31.51

2 Low 0.35 0.84 N/A 31.51

1 Up 1.63 1.74 2.48 19.54

1 Low 0.35 1.74 N/A 19.54

1 Up 1.63 1.74 2.48 18.70

1 Low 0.35 1.74 N/A 18.70

Room PSH

Name Type


csDimensions


VSC

Proposal

(%)

1.79 Pass

FFK54 K 2.50 8.46 3.07 3.81 Pass

Type 15a

FFK56 K 2.50 8.46 3.07

Type 15

39

40

41

42

47% 17% Pass

FFB55 B 2.50 3.37 3.49

24% 1% Fail

FFB57 B 2.50 3.37 3.49 1.96 Pass

3.84 Pass

Type

43

44

45

46

47

38

Table A2. ADF and PSH results for the First fl oor of the proposed development. Continuation

Table A3. ADF and PSH results for the Third fl oor of the proposed development.

2 Up 1.63 0.84 2.48 10.10

2 Low 0.35 0.84 N/A 10.10

1 Up 1.63 1.74 2.48 19.21

1 Low 0.35 1.74 N/A 19.21

4 Up 1.63 2.71 2.48 18.50

4 Low 0.35 2.71 N/A 18.50

1 Up 1.63 1.74 2.48 10.86

1 Low 0.35 1.74 N/A 10.86

1 Up 1.63 1.74 2.48 14.55

1 Low 0.35 1.74 N/A 14.55

4 Up 1.63 2.71 2.48 13.37

4 Low 0.35 2.71 N/A 13.37

1 Up 1.63 1.74 2.48 16.45

1 Low 0.35 1.74 N/A 16.45

1 Up 1.63 1.74 2.48 15.66

1 Low 0.35 1.74 N/A 15.66

1 Up 1.63 1.74 2.48 17.46

1 Low 0.35 1.74 N/A 17.46

1 Up 1.63 1.74 2.48 18.04

1 Low 0.35 1.74 N/A 18.04

1 Up 1.63 1.74 2.48 14.67

1 Low 0.35 1.74 N/A 14.67

1 Up 1.63 1.74 2.48 13.87

1 Low 0.35 1.74 N/A 13.87

30

31

32

33

34

35

36

37

26

27

28

29

Type 14

Type 14a

1% Fail

FFB53 B 2.50 3.92 3.27 1.54 Pass

FFK52 K 2.50 7.60 3.24 0.95 Fail 24%

18% Pass

FFB51 B 2.50 3.92 3.27 1.80 Pass

FFK50 K 2.50 7.60 3.24

FFK47 K 2.50 7.62 3.73 49% 20% Pass1.28 Fail

Type 13

1.05 Fail 44%

FFB49 B 2.50 3.37 3.49 1.76 Pass

FFB48 B 2.50 4.35 2.28 1.98 Pass

Type 12

FFB46 B 2.50 4.65 3.89 1.24 Pass

FFB45 B 2.50 4.04 3.27 1.33 Pass

64% 23% Pass

FFK43 K 2.50 3.85 2.00 0.88 Fail

FFL44 L 2.50 5.17 4.10 3.28 Pass