Energy

Energy assessment

Although the building did not feature any insulation measures prior to the works being carried out, its compact form and terraced nature mean lend it a compact heat loss area to floor area ratio. The area of glazing relative to floor area is also low (12%) which helps to reduce the relatively high heat loss that occurs through single-glazed windows.

The building had a BER rating of G 478 kWh/m2.yr prior to the works being carried out.

Areas

Ground floor 

First floor 

Whole dwelling 

Whole site 

82.5 sqm 

82.5 sqm 

165 sqm 

295 sqm 

Areas: Floor areas following works.

Ratios

Heat loss area / floor area 

Windows area / floor area 

Exposed wall area / total heat loss element area 

1.89 

0.12 

0.4 

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 & performance 

BER & energy value (kWh/m2.yr)  

before works 

BER & energy value (kWh/ m2.yr)  

after works 

418 kWh/m2.yr 

C1 

156 kWh/m2.yr

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 use  DEAP space heating cost estimate

Before 

After 

Saving 

% Saving 

€3,178 

€1592 

€1586 

50% 

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