The Building Research Establishment (BRE) has published the updated Green Deal Occupancy Assessment methodology. It is expected that commercial software developers will release updated versions of Green Deal Assessment software tools incorporating this methodology later in the year.
The methodology includes additional energy efficiency measure classes to be introduced within domestic Green Deal and made available for recommendation to customers during a Green Deal Assessment later this year. The new measure classes (specification measure code shown in brackets) will include:
- Circulation pump (EP): Replacement of old unrated central heating system circulator pumps (which are installed outside of the heat generator) by new pumps which meet the minimum European performance standards.
- Fan assisted storage heaters (high heat retention)(L2): Storage heaters that have well insulated heat storage cores meaning that heat loss into the room during periods when the heating is not on is greatly reduced.
- Glazing replacement (O3): Replacing the glass in pre-2002 u-PVC double glazed windows (which have a 12mm air gap) with argon or xenon filled 12mm double glazing, but leaving the old frames in place.
- Energy efficient luminaires (E2): Luminaires (complete light fitting, including lamp and an appropriate housing, shade or diffuser or reflector or other device for controlling the light output) that are fixed (wired in) to the dwelling, and that can only take low energy lamps.
- Party wall insulation (B4): Insulation of party walls constructed as cavity walls reducing cold air circulation (which creates a thermal bypass and increases the heat loss from a property).
- Storage waste water heat recovery (Y2): Heat recovery from hot water used in a bath or shower to heat water stored in a tank for later use.
The updated Green Deal Assessment software tools will provide improved functionality which includes:
- Green Deal Improvement Package: ability to lodge Green Deal Assessment Reports (GDARs) and use Green Deal Improvement Package (GDIP) function within the same software tool. The GDIP function allows Green Deal Providers and Advisors to tailor the package of recommended measures without the need to repeat the Occupancy Assessment.
- Measure performance differentiation in GDIP: the GDIP will give Green Deal Providers (Providers) more flexibility in specifying measure performance. For some insulation measures, the software will allow Providers to use the GDIP function to specify exactly what u-value an insulation product performs too. This will allow more credit to be given to higher performing insulation products, and also allow a lower u-value to be entered where there are mitigating circumstances as defined in Building Regulations. It would also allow a Provider to input the actual Solar PV panel size to be installed rather than a generic assumed size, which will give a more accurate savings estimate on the Green Deal Plan.
- Recognition of additional savings for condensing boilers and heat pumps: ability to recognise additional savings if the heat generator’s efficiency can be increased by the presence of low temperature heat emitters (heating systems in which the water leaving the heat generator can be limited to a lower temperature than in normal system design)
In parallel, DECC is updating the Green Deal Installer Standard (PAS2030), Code of Practice, Statutory Instrument and relevant guidance documents to cover the new measures.