Energy

Energy assessment

Although the building benefits from being semi-detached, the projecting return block to the rear, as well as high ceilings typical of the 19th-century, contribute to it having a relatively high heat loss area relative to floor area.

The building did not feature any insulation apart from a basic provision of quilt insulation to the attics. Although the gas boiler had been recently replaced, it was located in an outhouse; it was suspected the external portion of the primary pipework (connecting boiler to cylinder) was poorly insulated.  This would lead to heat loss and a reduction in efficiency of the heating system. Sash windows had been draughtproofed, and the main area of air infiltration was through the suspended timber floor to the front part of the house.

The building had a BER rating of E1 (319 kWh/m2/yr) prior to the works being carried out.

Areas: Floor areas following works.

Ratios: The heat loss area/floor area ratio indicates the compact envelope of the house – an important factor when considering wall insulation. Similarly, the window area/floor area ratio indicates the windows’ contribution to heat loss. 

Energy rating: BER/DEAP assessments were undertaken before and after the works which give a measure of the improved BER rating of the house. BER ratings are measured on a scale of energy consumption (kWh) per m2 of floor area per year (kWh/m2/yr), which is referred to as the energy value. 

Energy: Heating costs are estimated using energy consumption from DEAP and fuel prices (2013). Estimated costs can often be much higher than reality as the software assumes both a standardised heating pattern and temperatures throughout the house that may not reflect reality. Similarly, the actual costs can be higher if house owners exceed the standard heating pattern or assumed ventilation rates.