Code for Sustainable Homes

Laura Seymour

Overview of presentation

The Code for Sustainable Homes was

introduced in April 2007. In this

presentation we discuss:

• How the Code works

• Code ratings and setting benchmarks

• Energy and renewable technologies

• Overview of other topics assessed

• Case studies

Environmental issue categories assessed

• Energy & CO2 Emissions

• Water

• Materials

• Surface Water Run-off

• Waste

• Pollution

• Health & Well-being

• Management

Scoring

• Ratings from 1 star to 6 star

• Rating relates to

– Percentage of overall

points awarded across 34 issues

– Whether the mandatory

requirements for different ratings have been met

• Unclassified if the minimum requirements are not met

90+6

84-895

68-834

57-673

48-562

36-471

Total percentage

points score required

Star Rating

Example Certificate

Setting Benchmarks

2016

2013

2010

2008

Year certain Code elements may become

mandatory1

Aspirational Practice

Aspirational Practice

Advanced Practice

Best Practice

Good Practice

Standard Practice

Current benchmarks (but rapidly changing!)

6 star

5 star

4 star

3 star

1 to 2 star

Unrated

Code Rating

1 Draft Strategy for Sustainable Construction (2007), BERR

Approximate additional cost above Building

Regulations for achieving each Code Level

Figures are a per dwelling cost based on research carried out by English Partnerships

(A cost review of the Code For Sustainable Homes)

6

5

4

3

2

1

Code Level

-

£26,073

£15,184

£5,025

£2,326

£765

Traditional

Detached

-

£26,012

£14,726

£5,059

£2,506

£795

Traditional End

Terraced

-

£34,074

£8,297

£3,388

£2,385

£555

Traditional Low

Rise

-

£35,786

£16,953

£6,358

£3,797

£2,878

Traditional High

Rise

Energy- Mandatory Issues

Approx. 100True zero carbonCode Level 6

56100Code Level 5

1944Code Level 4

725Code Level 3

818Code Level 2

-10Code Level 1

Additional % improvement compared to previous Code level

% Reduction in CO2 emissions required compared to Building Regs

• Definition of zero carbon: the net carbon dioxide emissions for ALL energy used in the building is zero, including energy used in cooking and to power appliances which is not covered by Building regulations.

• Note that there is an exponential increase in CO2 emissions to gain higher Code Levels:

Reducing CO2 Emissions:Improved Building Design

1) Be LEAN- Use less energy

2) Be CLEAN- Use energy efficiently

3) Be GREEN- Use renewables

Steps 1 and 2: Improved building design

to reduce energy demand:

• Effective use of solar gain

• Low U values

• Low air permeability

• Energy efficient building services systems and controls

Potential improvement:

• Up to 20- 25% in housing using current best practice techniques

• Passiv Haus approach virtually eliminates need for heating and could

achieve up to 60% reduction

German Passiv Haus

Reducing CO2 Emissions:Renewable and Low emission technologies

Step 3: Choose a building services strategy that will reduce or eliminate CO2 emissions

Technologies that help to reduce heating/ hot

water demand:

• Solar hot water

• Biomass boilers

• Biomass combined heat and power/ CHP

• Community heating powered by waste

Technologies that help to meet electricity (lighting/power) demand:

• Solar photovoltaics

• Wind turbines

• Biomass combined heat and power/ CHP

• Small scale hydro power

Biomass Boiler

Wind Turbine

• ENE1 Dwelling Emission Rate: reductions in

CO2 emissions

• One of the few technologies available to provide renewable electricity, essential to gain higher Code levels

• ENE 7 Low or Zero Carbon (LZC) technologies: 1 credit awarded if 10% or 2 credits if 15% of total energy provided by LZCs.

• Need to consider solar design at an early stage. Related benefit- HW1 daylighting credit

Photovoltaics and the Code

Energy- Non Mandatory Issues

• Low energy lighting

• PIR/ daylight sensors/ timers

on external lighting

• Provision to dry clothes naturally

• Energy labelled white goods

• Low or zero carbon technologies

• Cycle storage

• Home office

Low Energy Light Bulbs

Solar Tube Skylight

Water

• Code Level 1 and 2: 120L/ person/ day

– Low water usage appliances

• Code Level 3 and 4: 105L/ person/ day

– Ultra-low usage appliances

– OR low water usage appliances PLUS rainwater harvesting/ greywater recycling

• Code Level 5 and 6: 80 L/ person/ day

– Ultra-low usage appliances PLUS rainwater

harvesting/ greywater recycling for toilet flushing and washing machines

• Affects aspects of living i.e. smaller baths, slower running showers and taps

• Additional credit for using rainwater for irrigation

Materials

• Environmental impact of materials

– Green Guide to Specification 2008

– Material specifications assigned a rating from A+ to E

– Mandatory requirement that at least 3 of the 5

building elements (roof, external walls, internal walls, floors, windows) have a rating A+ to D

• Responsible sourcing of materials

– Certified timber

– Other materials from ISO14001 or EMAS accredited manufacturers

hhh

Surface Water Run-off

• Management of surface water runoff

– Mandatory requirement that the peak rate of runoff does not increase

– Credits awarded for use of SUDs techniques to reduce runoff rates

• Flood risk

– Buildings will obtain a higher rating if they are located in a low flood risk area

Waste

• Site Waste Management Plans for site preparation/ construction phase mandatory

– Monitor waste generated and volumes recycled

– Set targets for waste reduction

– Outline procedures for meeting these targets

• Internal and external recycling bins

• Composting

Pollution

• Global warming potential (GWP) of insulants

• NOx emissions

Health and Wellbeing

• Daylighting

• Sound insulation

• Private space

• Lifetime homes

Management

• Home user guide

• Considerate Constructors Scheme

• Construction site impacts

• Security

– Secured by design

recommendations

Ecology

• Ecological value of the existing site

• Protection of ecological features

• Ecological enhancement

• Change in ecological value of the site

• Building footprint

Case Study: Illingworth Development

• Housing development in Halifax, West Yorkshire

• Most homes built to EcoHomes Very Good, two upgraded to CSH Level 4*

• First “saleable” Code Homes in the country to be completed

• Extra Over Cost: £14K/unit

Case Study: Illingworth Development cont.

• 54% Improvement in CO2

emissions achieved

• 17% through fabric improvements alone

- air tightness of 5m3/hr/m2

- careful detailing

- fully insulated 300mm cavity

- low U values including Krypton filled U values

• 2.5m2 solar PV panel

• Exhaust air heat pump instead of gas boiler

Case Study: Hanson EcoHouse

• CSH Level 4*

• High thermal mass

• Passive stack ventilation

• Ground source heat pump

• Solar hot water

• Rainwater collected for WC flushing and irrigation

• ISO14001 certified clay and concrete materials

Case Study: Stewart Milne’s Group Sigma Home

• CSH Level 5*

• Reduction in Carbon Dioxide Emissions

• Solar Thermal Water Heating

• Photovoltaics

• Micro-wind Technologies

• Grey water recycling

• Passive Ventilation

Stewart Milne’s Group Sigma Home built at BRE Innovation

Park

Questions

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