The homeowners invited us to retrofit their 1960’s dormer bungalow to make it as energy efficient as possible. They were concerned about the impact they have on the environment and they were keen to reduce this for themselves and future generations. Following an assessment from the Carbon Coop they had a good idea of what stye wanted to do and how they could achieve their aims.
The house had loft insulation, filled cavity walls and double glazed windows but the homeowners were disappoint with their monthly energy bills. However, The homeowners are happy with the way the house looked and weren’t interested in changing the brick finish to a rendered finish. They wanted to improve the energy efficiency but didn’t want to totally redecorate. This meant that internal and external insulation were not applicable in this case.
`The package of solutions included floor insulation, triple glazed windows and increasing the loft insulation to 400mm. We also redesigned the living room to incorporate a sloped roof & three Fakro roof lights.
The work progressed in three phases.
We installed floor insulation in the first phase, and triple glazed windows in the second.
The third phase was more disruptive. We gutted the living room, took the ceiling down and rebuilt it with a sloping roof and three rooflights.
The roof lights were high efficiency Fakro windows. The homeowners were keen to avoid products which were damaging to the environment (let’s face it all products damage the environment but it is possible to choose ones which do the least damage).
The floor and loft insulation were mineral wool. We used phenolic boards to insulate the living room ceiling because of its high performance. Around the perimeter of the roof we installed insulation. This helped to reduce the cold bridge at the junction between the wall and roof.
We replaced the windows in the second phase. We used windows from the Green Building Store. The windows are timber framed and triple glazed. The highest performing range (ultra) are passivhaus certified. The range we used was the performance range. The U’value was .8wm2/K, still well below the building regulations level of 1.4 wm2/K.