A consultation on proposed changes to the Standard Assessment Procedure has been launched by BRE this week.

The changes are being introduced to improve the accuracy of SAP assessments.

The main changes proposed are:

  • Space and water heating loads will be calculated on a monthly rather than annual rate to improve the accuracy of the figure and to take account of the effect of monthly variations in the weather on the building such as solar gain.
  • Space cooling requirements are included if the dwelling has a fixed air conditioning system, based on cooling a room or dwelling for 6 hours a day to 25C
  • The amount of domestic hot water required in a property is reduced on the basis of a reduced number of people for a given floor area. SAP will also reduce the efficiency of gas and oil boilers for both space and water heating by 5% if the boiler is used for space or water heating alone
  • A revision of the CO2 emissions factors for fuels
  • An amendment to a calculation of boiler efficiency from test data
  • A reduced level of internal heat gains is proposed
  • The benefits of thermal mass are taken into account in winter as well as summer to account for the effect of solar gains
  • The inclusion of party walls into heat loss calculations where a cavity construction a party wall can provide a mechanism for heat loss through air movement

The SAP consultation closes on 12 August

To view the consultation click

Source

Building Sustainable Design