Woodhouse Lane | Biddulph | Staffordshire
Environmental analysis, consultancy and production of refurbishment construction details to improve the thermal performance of a detached house.
Brief
SIX AD met with Jim Davies in August 2009, to discuss the feasibility of significantly improving the thermal performance of Jim’s detached dormer bungalow. In the 1980’s, Jim raised the roof height to include a first floor level to his house; this provided much needed space for the family, however air leakage and rapidly changing temperatures have caused discomfort over the years.
Jim explained that he had read a newspaper article that claimed that an average sized house could be ‘super-insulated’ for around £20,000 and that this was something that he would like to investigate. SIX AD we’re appointed to address the feasibility of introducing improvements in the following areas :
- Insulation to the roof
- Ventilation Control
- Window improvement / replacement
- Creation of a lobby to the front door
- Improved air tightness to the back door
- Insulation to the ground floor
- Integration of solar thermal panels in to the roof
Challenges + Opportunities
The primary concern was to provide better control over heat losses from the house; by controlling heat losses, we would also have better control over heat gains, therefore improving comfort in the house.
The junction between the existing roof and the external walls was complex because of the previous roof lift and the flared eaves of the chalet style roof. The gap between the original ceiling and the first floor joists also allowed cold air to freely flow through the heart of the house and in turn vent that valuable heat to the outside air.
The existing windows were already double glazed, however Jim was very impressed with a triple glazed window system that he had observed close hand while visiting family in Finland. We agreed to produce a detailed window schedule and explore cost options.
SIX AD produced a feasibility study that addressed the factors within the property that affected air tightness, thermal comfort and moisture build-up; we used this document as a basis for further discussions with Jim in order to prioritise a schedule of works.
Proposals
SIX AD recommended that the roof be converted to providing a warm roof solution; this meant that the cold air within the attic space would be excluded in the future and that the air temperature within the attic would then act as a capacitor for temperature in the rest of the house. The insulation within the roof would be carried through to the eaves, where it would connect with the insulation in the external walls, providing a continuous thermal line and overcoming the problem with air leakage between the ‘sandwich’ of ground floor ceiling joists and first floor joists.
SIX AD modelled the proposals in 3D to demonstrate to the Local Authority that planning permission would not be required as the change in roof height was marginal. The model also showed the position of new solar panels and the configuration of the proposed windows and rooflights. SIX AD produced detailed drawings of the proposed new construction, to demonstrate to the builder where the ‘air tightness’ line would be.
Services
SIX AD were appointed to fulfill a bespoke appointment on the project, which included the following scope of service :-
Preparation
Conduct an appraisal and develop an accurate brief. Undertake a detailed dimensional survey and condition survey. Identify areas of poor performance and produce a Feasibility Report with recommendations for remedial measures.
Design
Assist with the specification of all construction elements and prioritisation of proposed works. Develop design options for consideration by the Client.
Pre-Construction
Develop and collate tender documentation ready for issue to the Clients chosen builders.
Conclusions
Some elements of the proposals were omitted from the final scheme for practical reasons; for instance the front entrance porch would have required planning permission, in order to ensure that it provided adequate floor area to fulfil its purpose as a welcoming and light-filled space. It will be possible to integrate the porch in a future phase.
"SIX AD produced a new way of tackling the problem of our poorly insulated house which nobody had previously thought of. As the work draws to a conclusion we can already feel the benefits on these cooler evenings. As energy bills rise I shall appreciate the work of SIX AD more and more."
James Davies
Client
