proposed changes to part l 2010

 

----> header/Chartered Surveying/22_king_st.jpg

 

Changes to the 2006 Criterion

 

SAP Software Changes

 

There will be changes to the SAP software as follows:

 

  • Calculation will be on a monthly basis rather than annually and may take into account winter thermal mass and air conditioning.

 

  • The benefits of thermal mass are taken into account in the winter as well as the summer. Currently the tool allows for the cooling effect of thermal mass in the summer but doesn't allow for reduced heating demand in the winter when solar gain heats up the thermal mass of a building.

 

  • The energy used by air conditioning systems is now accounted for in SAP, which means it will be harder to get homes fitted with air conditioning to comply with Part L.

 

  • Dwellings with no secondary heating no longer have to assume on peak electric secondary heating

 

  • All fixed low energy lighting is included in the DER assessment and not just 30% as is considered currently.

 

  • Design limits for Building Services have been expanded to cover micro generation of heat and electricity by heat pumps, solar thermal panels, CHP, wind turbines and PV.

 

  • Despite the fact that air conditioning can be modelled in SAP 2009 assessment of mechanically cooled dwellings continues to be as though the cooling were not present.

 

  • Clearer rules for air permeability assessment at the as Built stage, involving more pressure testing, a revised sampling methodology and a clear statement about what value to be used in untested dwellings.

 

  • 25% to be added onto calculated values if accredited construction details not used.

 

  • Party walls are no longer assumed to have a u value of 0.0 W/m2K. The value depends on the construction detail.

 

  • The exemption for conservatories of less than 30m2 will be removed.

 

  • The assumed hot water usage in a dwelling is reduced by 5% if the dwelling is designed to achieve a water use target of not more than 125 litres per person per day.

 

  • In SAP 2005, you could only have one central heating system backed up by one room heater. SAP 2009 enables you to have two central heating systems or boilers running off different fuels.

 

  • There will be some dispensation for rural communities not on the gas grid. The notional building will be assumed to be heated by LPG or oil.

 

  • Emissions from electric heating systems will be capped at the same level as for fuel oil heating.

 

  • A notional building model will still be used to prove compliance but underpinning the proposal will be a new set of emission factors based on an analysis of carbon levels and climate change impact of different fuels, which will be part of a separate consultation.

<< Previous page