Achieving Code for Sustainable Homes Level 5 & 6

Predicted CO2 emissions from the dwelling

Code for Sustainable Homes Level 5

To assess whether a dwelling design achieves the 100% CO2 reduction, the target emission rate (TER) methodology should be used (as defined in national building regulations). The TER is expressed in terms of the annual CO2 emissions, in kg per m2 of floor area.

Different dwellings will have different emissions targets, because the TER is based on floor area, dwelling shape and other factors, such as the heating fuel used.

Under national building regulations, the dwelling’s DER (dwelling emissions as designed) should be equal or less than its TER to pass.

A similar method is adopted here to assess compliance, but in order to give the desired CO2 savings, the DER has to be equal to or less than 0kg CO2/m2.yr., i.e.:

DER=0

Code for Sustainable Homes Level 6

To achieve Code for Sustainable Homes level 6, true zero carbon status must be attained. This means that, in addition to negating CO2 from space and water heating, and lighting (as per level 5), all CO2 emissions from cooking and other domestic appliances must also be accounted for.

These additional emissions should be calculated using the methodology within the Code for Sustainable Homes technical guidance. The calculated emissions for cooking and appliances should then be subtracted from the actual CO2 emissions to find the final DER which is required to achieve true zero carbon.

1. Calculate the TER for level 5 as above.

2. Calculate offset using Code for Sustainable Homes technical guidance – please see the Code for Sustainable Homes technical guidance document for the appropriate methodology.
See www.planningportal.gov.uk/uploads/code_for_sustainable_homes_techguide.pdf

3. Subtract offset from code 5 TER to find code 6 TER.

4. Ensure DER meets code level 6 TER.

At code levels 1 through to 5 of the Code for Sustainable Homes, standard SAP compliance methodology must be adhered to i.e. only 30% of low energy lighting may be claimed, and a secondary heating system has to be assumed. However at code level 6, the actual CO2 emissions should be used, as these take into account the true level of low energy lighting installed, as well as relaxing the need to include a secondary heating system when none is installed.

Design Backstops

Notes

1. This column gives a summary of the national building regulations in England and Wales and Northern Ireland, but the official 1. documents should be referred to for detailed guidance.

2. Please note that all documents referenced beginning with CE, GIL and GPG can be downloaded from the Energy Saving Trust’s 2. website – please visit http://www.energysavingtrust.org.uk/housing

3. Please see 3. http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_DOMHEAT.pdf

4. Please see 4. http://www.sap-appendixq.org.uk

Follow this link to download a free guide from the Energy Saving Trust.