Assessment Methods

Code for Sustainable Homes and EcoHomes

To enable the construction industry to measure the sustainability of dwellings, BREEAM has developed two environmental assessment schemes: EcoHomes and the Code for Sustainable Homes (usually shortened to “Code”, or sometimes “CSH” or “CfSH”). Assessment against these schemes is carried out by independent, licensed assessors.

Environmental Scope

Both schemes take account of a broad range of issues, from bicycles to bathtubs and from recycling to renewable energy. In fact cycle storage, internal water use, low and zero carbon (LCZ) energy sources and recycling facilities are just four aspects of over 30 issues that are examined in detail. Each issue has its own scoring method. A housing development, or a single house or flat, can be assessed against each issue in turn, and a number of credits awarded.

Energy

Carbon footprint is in effect assessed for the whole life cycle of the dwelling, from construction, through everyday use, to demolition and disposal. It takes account of the energy embodied in materials, as well as the energy used in construction. However, the major factor is the average energy used during its occupation as a home.

Comparison with Other Factors — Credit Values

Energy issues account for just one quarter of those examined. Diverse matters such as security and sound-proofing are also covered. Comparing the environmental impact of light fittings and lavatory cisterns is like comparing chalk and cheese, but the BRE has achieved it by consultation with experts from a broad range of disciplines. Different weightings are applied to the issues, so that the value of a credit depends on the issue. Credit value is expressed in points or a percentage, which amount to the same thing as there are 100 points available.

Scoring and Levels or Ratings

By adding up the credit values for all the issues we get a percentage score to evaluate the sustainability of the dwelling or development. To facilitate the setting of targets, the Code has performance bands from Level 1 to Level 6 (top), while EcoHomes has descriptive ratings from “Pass” to “Excellent”.

Application

Both schemes are applicable to houses and flats to be used as single dwellings. Shared facilities (e.g. common rooms) cannot always be assessed, and neither scheme is capable of assessing management facilities (e.g. warden’s offices). Sometimes therefore a lower score will result. If there are to be significant shared or management facilities then Multi-Residential would be a better scheme to use.

Some Important Differences between Code and EcoHomes

• Each Code Level also has certain mandatory standards for some of the issues, notably Dwelling Emission Rate (typical CO₂ emissions while the home is in use) and Indoor Water Use.
• PCS Assessment is mandatory under Code but optional for EcoHomes.
• Each individual dwelling receives its own Code rating and certificate, while with EcoHomes it’s the development as a whole that is rated and certified.
• The Code has taken over as the preferred method for assessing new-build dwellings. Refurbishments on the other hand continue to be assessed under EcoHomes.

 

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