Achieving the Target Emission Rate (TER) and the Target Fabric Energy Efficiency (TFEE)

Appendix R of SAP 2012 provides a specification for a notional dwelling which meets the new standards.
If a dwelling is built conforming to Appendix R values it will beat the TER and also beat the TFEE by 15%.
It is however often not possible to conform to all the stipulated values on a specific project and it becomes necessary to compensate for shortcomings in one area with improvements in another.


Element or system Value
Size and shape As proposed dwelling
Opening areas Up to 25% of total floor area
External walls 0.18W/m2k
Party walls 0.00W/m2k
Floors 0.13W/m2k
Roofs 0.13W/m2k
Windows 1.4W/m2k
Thermal mass Medium (250KJ/m2K)
Ventilation System Natural (with extract fans)
Air permeability 5.00 m3/m2/hr@50 Pa
Heating system Mains gas, boiler and raiators
Boiler 89.5% (SEDBUK 2009) efficiency
Controls Time and temperature zone control
  Modulating boiler with interlock
  Weather compensation
Secondary heating None
Low energy lighting 100%
Air conditioning None
Thermal bridging Calculated using psi values in Table R2