Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

Passivhaus &Design for Future Climate

Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

Knights PlaceAffordable Passive Houses for Exeter

Our Team• Exeter City Council,

Client, Project Manager, Structural and Civil Engineers

• Gale & Snowden Architects, Mechanical Engineers, Landscape Architects

• Jenkins Hansford Partnership - QS

Passivhaus certified

Passive natural vent Permaculture design

Landscape integration

Exeter Infill Sites •12 sites in Exeter

•120 affordable units

• individual designs

•Passivhaus compliant

•Minimum CSH 4

•Lifetime Homes compliant

Aims to • Provide affordable housing for Exeter

• Raise standards of housing in Exeter.

• 18 units• 15 month construction programme• £2.1m development cost• £1.15m in HCA grant funding• £1,450 /m² Construction Costs

• Project drivers:

– fuel poverty– energy sustainability– future climate change– low maintenance– downsizing– healthy buildings

Knights Place Project Summary

Passivhaus – What is it?

• Voluntary energy standard and a design methodology

• Suitable for most types of buildings including dwellings, offices, schools, sports halls, swimming pools, arctic research stations etc.

• Evolved in Germany in the 1990ies• Today more than 35,000 built examples

but only 17 in the UK• ~1,900 have been certified by the PHI as

‘Quality Approved Passivhaus’• The Passivhaus Standard can be applied to any

climate• How does it compare to ‘the Code’? It doesn’t.

Arctic Station / Samyn & Partner

Passivhaus Refurb / G&S

Rowan House / G&S

Knights Place / G&S

Passivhaus – Certification

For the UK, a dwelling is deemed to satisfy the Passivhaus standard if the following criteria are met:

- Space Heating Demand <15 kWh/m²/yr

- Or Heating Load <10 W/m²

- Primary Energy Demand <120 kWh/m²/yr

- Frequency of Overheating <10%

- Air tightness <0.6 ac/h@50Pa

- All of the above must be verified using the Passive House Planning Package (PHPP) and appropriate regional climatic data – not SAP

PHI functional definition:

‘A Passivhaus is a building, for which thermal comfort can be achieved solely by post-heating (or post-cooling) of the fresh air, which is required to maintain sufficient indoor air quality.’

… meaning no other conventional heating system will be required.

Passivhaus – How does it work?

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulation

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Thermal Bridge Free(following the PH method)

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Thermal Bridge Free(following the PH method)

High Performance Windows and DoorsUvalue (instl) < 0.85 W/m²K

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Thermal Bridge Free(following the PH method)

High Performance Windows and DoorsUvalue (instl) < 0.85 W/m²K

>75% efficient MVHR(following the PH method)

Knights Place Exeter - Section

Passivhaus – How does it work?

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Thermal Bridge Free(following the PH method)

High Performance Windows and DoorsUvalue (instl) < 0.85 W/m²K

>75% efficient MVHR(following the PH method)

Optimized Solar Orientation

Compact Building FormKnights Place Exeter - Section

Passivhaus – How does it work?

Knights Place Exeter - Section

Energy Losses Energy Gains

Internal Gains

Solar Gains

HeatingVentilation

Losses

Transmission Losses

High levels of insulationUvalue < 0.15 W/m²K

Continuous Air tight Barrier< 0.6 ac/h @ 50 Pa

Thermal Bridge Free(following the PH method)

High Performance Windows and DoorsUvalue (instl) < 0.85 W/m²K

>75% efficient MVHR(following the PH method)

Optimized Solar Orientation

Compact Building Form

Passivhaus – Why bother?Minimal Energy Losses

Thermal Imaging of Knights Place proves:

Implementing the Passivhaus methodology has reduced heat losses and thermal bridging to a minimum.

Passivhaus – Why bother?How does it compare to a standard build?

The holistic design strategy allows for energy savings of up to 75%, making these units truly affordable and protecting future tenants from fuel poverty.

TER = SAP ‘Target Energy Emission Rate’ if building had been built to 2006 Building Regs standardsTFA = Treated Floor Area

Passivhaus – Why bother?How does it compare to a standard build?

G&S received Government funding through the TSB to monitor the energy performance of Rowan House and Knights Place.The average space heating demand for Rowan House in 2011 came out at 12 kWh/m²/year

Knights PlaceReduced running costs

On average energy prices in the past 10 years have increased by approximately 10% per annum.  

With current trends in energy and fossil fuels it is not likely that this will change over the next 10 years.    Assuming a 10% increase per annum, £800 today (typical heating and hot water cost per annum of an existing flat) would be in 5 years time = £1171, in 10 years time £1, 715

The project has recently received funding from TSB to monitor energy and building use.

Comparison of Energy Costs - EPC | PHPP | UK Standard   

  EPC(flat 5)

Passivhaus Planning Package

Approx UK Standard

 units

Primary Energy Use 73 114 165-250 (kWh/m2/year)

Heating Demand 2 12 60-90 (kWh/m2/year)

CO₂emissions 0.6 0.9 2.5 (tonnes per year)

Lighting £24 £9 £45 (per year)

Heating £18 £95 £450-500 (per year)

Hot water £86 £150 £230 (per year)

Healthy Buildings Building Biology Principles • Non-toxic eg: non

VOC materials

• High quality ventilation

• High levels of natural daylight

• Thermal comfort

• Avoidance of dust mites by good design and materials selection

• User control

• Radial wiring to reduce low frequency Electro-Magnetic Fields (EMFs)

• Non PVC materials specified

Landscaping Permaculture principles

Landscape Architect and Species expert as part of Gale & Snowden in-house design team.

Emphasis on integrated design using Permaculture principles

Working with natural system not against

Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

St LoyesClimate proof Extra Care for Exeter

Project Starting Point

• New build 50 flats and communal facilities

• Restrictive site• Shading of external

courtyard space making it unusable

• Institutional building with central corridor

• Natural cross ventilation not possible

Shading diagram June 21st 18.00

There is an overwhelming scientific consensus that the climate is changing

We will need to adapt our buildings so that they can cope with

higher temperatures, more extreme weather and changes in rainfall

Design for Future ClimateClimate Change Adaptation Strategy

South West climate change is likely to have the following effects:

• average temperatures in the south west are expected to rise by 4-6 degrees over the next 80 years

• average solar radiation is expected to increase significantly, increasing the exposure to UV

• increase in exposure to pollen and higher ozone levels

• wind loads and storm intensity are likely to increase

• 50% reduced rainfall in summer with longer periods of drought and

• 50% increased rainfall in winter

Weather files used: 2030, 2050 & 2080 @ 50 percentile with High CO2 Emission Scenario

MethodologyAnalysis• Literature research• Case studies• Thermal modelling past

projects with future weather files

• Risk Assessment• Ongoing IES thermal

modelling at early design stages

• PHPP (Passive House Planning Package)

• Fluid dynamics analysis• Occupant heat stress

analysis• Cost matrix• Integrated team studio

working

2030, 2050 & 2080 @ 50 percentile with high CO2 emission scenario

Future Climate Change Risk Assessment

• User group vulnerability• Increased internal temperatures • Increased external temperatures • Changing rainfall patterns • Localised air pollution

Key

Comfort

Construction

Water Management

Climate Change Adaptation Design• High levels of

Dementia care• Cluster design• Usable soft-centre

courtyard• Connection to others• Community and

privacy

low energy - healthy - integrated landscape – non institutional

Passive Adaptation 4 Heat1. Passive• Cross ventilation• Super insulated

envelope• Intelligent

ventilation control• Extracting heat at

source• Mass vs light weight• Living plants /

landscape• Solar shading

Cross flow vent 10-15% over heating improvement over single sided ventilation

Overheating Criteria not to exceed 1% occupied hours over 25oC

Super-insulated, air tight envelope helps to stabilise internal temperatures and reduce solar gain penetration 3 – 6% improvement

Intelligent window control 4% improvement

Mass vs light weight 2-4% improvement with mass

Local shading 2% improvement

Relocation of internal heat gains from plant outside thermal envelope 5% improvement

Green microclimate reduce summer temperatures by 3oC

Evaporation / Transpiration

Green roofPleasant shaded spaces for cooling

Less 1.5oc by microclimate

Active Adaptation 4 Heat2. People centred• Management / staff heat

stress awareness and training

• Drinking points• No cooking in flats

during heat waves• Room ceiling fans

3. Active design• Heat extraction at

source• Temperature sensor

warning system for vent control

• MVHR coupled with ventilation control

• MVHR ground cooling

Early warning temperature system to aid intelligent window ventilation control

MVHR Activated during heat waves for minimum fresh air

Windows closed when external air temperatures are hotter than inside 2-4% reduction

Ceiling mounted fans increase air movement and sweat evaporation

Heat extract at source

Supply air reduced by 10oC in summer combined with closing windows above 22-25oC reduces overheating to zero 2080

Close loop ground to brine heat exchanger

Drinking point to aid hydration

Adaptation 4 Air Pollution Healthy design• Good ventilation rates• Thermal comfort• Filtration of pollutants

and pollen using MVHR when needed

• Removal of CO2 by

MVHR• Non-VOC materials• Plants used to help

clean air• Cleanable surfaces to

reduce dust mites infestation

• Radial wiring to reduce EMFs

Plants removes VOCs & CO2

MVHR removes VOCs & CO2

VOCs

CO2

MVHR with pollen filter for affected users

MVHR at night for security on ground floors

Smoke / smog particulates filtered by MVHR

Mosquito insect mesh on opening windows in summer

Pollen

MVHR provides good air quality in bedrooms at night when windows are shut

VOCs

Building and Landscape design working together to provide healthy environments

Courtyard design provides fresh air microclimate

Adaptation 4 RainfallWater strategies• Water retention via

planting and landscape design

• Irrigation SUDs system

• Rainwater collection

Oversized gutters and downpipes

Wetter winters dryer summers – future rain files need adapting for designers

Rain water harvesting tank on flat roof:Option A – ground and plants irrigation onlyOption B – as A plus flushing WCs, Sluices and laundry

For flushing WCs

For sluice rooms

Storage point at ground level

Water attenuation by rootsRainwater storage crate system = underground swale irrigation system

Lower collection point for overflow

SUDS / Attenuation system

External area left for rain water harvesting tankRain water harvesting under ground option B

Aquaculture

Integrated Landscape Landscape• Thermal comfort - cooling, shading• Water - collection and reuse• Biodiversity• Health & well being• Plants choice

- species suited to challenging conditions, winds, drought, occasional flooding

• Minimise hard surfacing

Roof GardenCooling effectHealth and WelfareBiodiversity

Adaptation for Heat, Rainfall, and Air pollution,

Green roof 70-200cm substrateSedum, herb, grasses Biodiversity.Reduce peak runoff.Reduce annual runoff by50-60%Cooler surfaces Improve air quality

Deciduous climbers growing up balconieslocal shading

Green microclimate reduce summer temperatures by 3oC

Evaporation / Transpiration

Pleasant shaded spaces for cooling

Permeable paving to allow percolation into soils

Rainwater collectionFor reuse in garden areas

Layered structure to planting, deciduous canopy for summer shading

Sequence of rainwater storage crates for natural percolation to planting and pumped irrigation

Courtyard fresh airmicro-climate

Internal planting remove VOC’s and CO2,

Design to allow flooding into central planting shallow swale

Life Cycle CostingCumulative Energy Related Costs

Cumulative energy costs for an Extra Care facility, built to 2010 Building Regulation requirements, for heating, cooling and additional future investments required to maintain adequate comfort conditions over the lifetime of the building.

All costs have been discounted at 5% to represent present value. An annual increase in fuel costs of 4% has been allowed for and a reduction of heating demand of 30% from 2050 to 2080 has been included.

Life Cycle CostingCumulative Energy Related Costs

Cumulative energy costs for an Extra Care facility, built to Passivhaus Standard, for heating, cooling and additional future investments required to maintain adequate comfort conditions over the lifetime of the building.

All costs have been discounted at 5% to represent present value. An annual increase in fuel costs of 4% has been allowed for and a reduction of heating demand of 30% from 2050 to 2080 has been included.

Life Cycle CostingCumulative Energy Related Costs

Comparison of Cumulative Energy costs:

Payback of additional initial investment after approx. 13 years

All costs have been discounted at 5% to represent present value. An annual increase in fuel costs of 4% has been allowed for and a reduction of heating demand of 30% from 2050 to 2080 has been included.

South Elevation

North Elevation

Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

PassivOffice@ Devonshire Gate, Tiverton

David Disney, Devonshire Gate

New Office Project

• First Phase• 1250 sqm• Passivhaus design• Natural ventilation in

summer• Optimum day light• Planning restrictions• RIBA Workstage

E/F/G

Low energy - Healthy - Integrated landscape

The Project - RIBA Workstage EFG

Methodology

Analysis• Literature research• Case studies• Thermal modelling past

projects with future weather files

• Ongoing IES thermal modelling

• PHPP (Passive House Planning Package)

• Occupant heat stress & impact on productivity analysis

• Cost matrix• Integrated team studio

working

Day light modellingIn IES

Solar XXI Building(Lisbon, Portugal)

Methodology

Climate change related risks are rated for their probability and their potential impact resulting in a risk magnitude.

Following detailed analysis of building’s exposure to climate change related risks, the 2030, 2050 & 2080 @ 50 percentile with high CO2 emission scenario was chosen.

Climate Risk Radar

Findings - Thermal ComfortSuper insulated envelope

High performance windows

Air tightconstruction

ThermalBridgefree

Inclusion of thermal mass

Externalshading

IntelligentWindow control

ReduceInternalgains

MVHRGroundcooling

Additional measures to reduce the risk of overheating

Supply air reduced by 10°C in summer combined with closing windows above 22-25°C reduces overheating to zero in 2080Th

erm

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odel

ling

resu

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Fre

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f ove

rhea

ting

Now 2030 2050 2080

Findings – LandscapeGreen roofAttenuationEvaporation cooling

1. Planting micro climates

2. Resilient landscaping

Transpiration cooling

Reduce hard surfaces next to building

Shading from trees

Shaded external working areas

Ponds to moderate flood/drought cycle

Earth bank and trees act as windbreak

Planted areas to increase infiltration

Root system for erosion control and slope stabilisation

Design for severe weatherDriving rain •robust timber rain screen cladding•enhanced window and door specification and detailingIncreased wind severity•eaves and verge robust details•Robust materials and secure fixings Increased UV•turf roof•timber cladding Future adaptability•future addition for shading devices•Future external working areas Flooding events •oversized rainwater goods and drains•attenuation ponds

Passivoffice @ Devonshire Gate detail design drawings

Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

PassivPoolSwim4Exeter

Exeter OfficeExeter Bank Chambers67 High StreetExeterDevonEX4 3DTTel. 01392 279220Fax. 01392 279036

Bideford Office18 Market Place

BidefordDevon

EX39 2DR(Registered Office)Tel. 01237 474952Fax. 01237 425669

www.ecodesign.co.uk

Passivhaus &Design for Future Climate