Windows

To the rear of the property all windows and doors have been replaced with high performance low e argon filled IG units. Windows to the front (5 number) are, however, box sash windows which form a significant feature of both the house and the conservation area in which it is situated. These windows are to be fitted with very high performance secondary double glazing, which will mean that the most difficult windows become triple glazed.

Roofs

The Main house roof is conventional and high levels (300mm) of insulation has been installed.
More problematic is a small room to the rear of the property. This part of the building predates the main house and is believed to be a part of the original cottage on the site. Here 50mm Kingspan insulation has been installed between rafters, with cross battens with a multi foil insulation material stapled in place. The foil insulation was carefully taped at joins and edges, before adding further battens to take a plasterboard finish. Multi foils are the subject to much debate, as to thier true insulation value, but combined with at least some conventional insulation a reasonable level of insulation close to current minimum new build levels has been achieved. Long term the roof covering will be replaced with additional extenal insulation board.

Floors

Existing irregular thickness 50mm - 90mm rough stone floors were stripped out. A new sand bed was layed and then Underfloor heating pipes fixed to reinfocing mesh laid on 110mm Kingspan insulation. A concrete slab was laid on this and the original stone floor was re laid after cutting back the stone to 40 - 50 mm thickness.





Underfloor Heating
and the New Floor

Walls

Existing walls are generally 350mm Cotswold stone any external insulation system would be unacceptable to the planning authority in a conservation area.
Walls have been upgraded by the application of a plasterboard laminate total thickness 92 .5mm giving a U value of 0.22 w/sqm k. This standard is somewhat better than that required by current building regulations. There are relatively small areas of external wall, particularly around window and door jambs and reveals, where this level of insulation can not be maintained using conventional products. The use of Proctors Spacetherm would have been a good way to deal with these isolated "cold bridge" areas. Unfortunately this product is still extreemly expensive and as a compromise the jamb areas were insulated with a reduced thickness of Kingspan Insulation.

First Things First

The parts of the house that need to be considered. What did we do first to
improve our Carbon foot print? The areas and subjects to think about were the thermal performance of the fabric:
Walls
Floors
Roofs
Windows & Doors
Improved Services:
Electricals and Lighting
Heating Systems
Ventilation Systems
Water Conservation

What we're doing

Current government policy is to move towards net zero carbon housing over the next few years. This presents the house building industry which a major challenge in the use of building systems, products and materials, in all new housing development

The existing housing stock, will remain in use for many years. Part L of the Building Regulations for the first time addresses this issue by requiring elements of existing buildings to be upgraded thermally when those elements are replaced or altered significantly. It is no longer acceptable for example to re-plaster a whole wall without making at lease some attempt to upgrade its thermal performance.

This project aims to demonstrate and research methods of building construction that can be used to not just upgrade a sensitive building, in compliance with the existing Part L requirements but to explore how thermal performance well beyond current standards can be practically achieved. How far towards a net Zero Carbon House is it possible to reach, how do these practical standards compare with current building regulation standards and how do they compare to green building standards such as the Passive Haus.