On 11 November 2010 a new edition of the Code for Sustainable Homes was published. Although many items within the code have been updated, the most significant changes have occurred to the energy and emissions category of the code. This document describes the main changes to this category.
ENE1 Dwelling Emissions Rate
This issue is now aligned with 2010 Building Regulations. As a consequence the number of credits that are available under this issue has been reduced from 15 to 10. Now only for CSH level 4 and above an improvement over the building regulations is required. Table 1 gives an overview of the requirements to gain credits and CSH level 4 and above.
Table 1.Dwelling emission rate Improvement of Credits Mandatory requirement
DER/TER (2010)
>= 8% 1 >=16% 2 >= 25% 3 Level 4 >= 36% 4 >= 47% 5 >= 59% 6 >= 72 % 7 >= 85% 8 >= 100% 9 Level 5 Zero Net CO2 10 Level 6
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ENE2 Fabric Energy Use
Previously ENE2 related to the heat loss parameter of the building. A maximum of two credits were available. The 2010 edition of the Code for Sustainable Homes now considers the fabric energy efficiency. There are nine credits available. For Code levels 5 and 6 meeting the requirement for 7 credits is mandatory. There are two sets of performance criteria: one set is for apartment blocks and mid-terrace houses and the second set is for other dwellings (end terrace, semi-detached and detached. The criteria are provided in table 2.
Table 2 Fabric Energy Efficiency Criteria Fabric Energy Efficiency kWh/m2/yr Credits Mandatory requirement Apartment blocks Other houses
Mid Terrace <=48 <=60 3 <=45 <=55 4 <=43 <=52 5 <=41 <=49 6 <=39 <=46 7 Levels 5 and 6 <=35 <=42 8 <=32 <=38 9
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ENE3 Energy Display Devices
The previous issue for installing energy efficient internal lighting has made place for credits when energy display equipment is installed. There are two credits available. One credit can be achieved by either displaying the electricity use or the primary heating fuel consumption. Two credits are available where both types of energy use are displayed.
ENE7 Low and Zero Carbon technologies
There are still two credits available for installing LZC technologies: 1 credit where 10% of the carbon from regulated energy use is displaced and 2 where at least 15% of the carbon is displaced.
To align the issue with the updated SAP methodology a new standard case has been defined. Table 3 provides the details.
Table 3. Parameters to calculate CO2 emissions from the Standard Case
Element of System Value
[1] Main heating fuel (space and water) Mains gas
[2] Main heating system (and second Boiler and radiatord
main heating system where specified) Fully pumped circulation
Water pump in heated space
[2a] Boiler SEDBUK (2009) 88%
Room-sealed
Fanned Flue
On/off burner control
[2b] Heating system controls Programmer
Room thermostats
TRVs
Boiler interlock
[3] Secondary heating fuel (where
secondary heating is specified) Electricity [3a] Secondary heating system (where
secondary heating is specified) Panel, convector or radiant heaters
[4] Hot water system Stored hot water, heated by boiler only
Separate time control for space and water heating
[4a] Hot water storage 150 litre cylinder insulated with
35mm of factory applied foam
[4b] Primary water heating losses Primary pipework insulated
Cylinder temperature controlled by thermostat
[4c] Technologies covered by Appendix H of SAP None specified
[5] Technologies covered by Appendix M of SAP None specified
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Approximate Weighted Value of each credit
As a result of the increase in the number of credits that are available within the energy and carbon emissions category, the weighted value of each of the credits within this category is reduced to approximately 1.17.
