Thursday, 12th April, 2007

Re;    Site investigation

Summary

In order to improve the comfort and energy efficiency of the property,you should consider a range of options which could include: replacementof doors/windows; insulation of exterior walls; management of moisturegenerated within the kitchen and bathroom; replacement of centralheating boiler and modification of the system, possibly in conjunctionwith installation of underfloor insulation; a properly executed  loftconversion would be particularly beneficial. 

Kitchen / Diner

The existing French doors are single glazed and have poor airtightness, allowing excessive air infiltration. They need to bereplaced as a priority. Any replacement should offer a significantimprovement in thermal performance, and I would recommend using a highperformance softwood product from Scandinavia, or possibly a bespokeproduct in French oak. See foot of letter for some contacts/links. PVCproducts are not compatible with sustainability due to high embodiedenergy and poor thermal performance, and likewise avoid tropicalhardwood (high embodied energy, poor resistance to degradation in ourtemperate weather). At the moment, large amounts of glazing in the kitchen/diner  offer poor thermal performance, so you should considerrationalising glazing to maximise daylight whilst reducing energy loss.There are a number of ways that this could be done, according to yourbudget and aesthetic preferences. 

Reducing air infiltration with improvements to doors and windows canlead to an increased risk of condensation, especially in kitchens or bathrooms where moisture is produced. The mechanical extractor vent iscurrently installed above the cooker and is attempting to push moistair up a long chimney, and it is unlikely to be effective (it should bepulling, however this is impractical to install in a vertical flue). One option would be re-routing horizontally across the ceiling to anexternal wall. 

As your kitchen has two external walls it has a large surface area to volume ratio, which is again thermally inefficient. I would recommend insulating internally with a product such as Kingspan foam backed plasterboard, incorporating a vapour barrier. 

Heating

I would not recommend underfloor heating; but a new boiler is a mustand reducing the volume of the system would improve efficiency, if done in conjunction with  the other improvements suggested. I would recommend solar hot water, however this should be installed as part of the loft conversion.

Loft Conversion

In terms of improving thermal performance, work on the roof space has great potential, and you need to decide whether you wish to implement a loft conversion at an early stage, or just make other improvements such as increasing the thickness of the insulation in the loft, and sealing round the openings made for the downlights. As the space is very large it would lend itself to easy conversion, and could accommodate a solar hot water system, new boiler and tank, super-insulation, en-suite master bedroom with balcony, or two  regular bedrooms. A loft conversion is a large and expensive job, and I would recommend that you take particular care when making decisions relating to it, as mistakes could be costly.

The house would possibly need an extra bathroom as a result of allthat (would need to check with the City Council's Building Control team).

Would also recommend external insulation to gable wall, as it is alarge area with no windows, and so would be easy to do with a good return. 

Miscellaneous

Fitting a porch/lobby door would be worthwhile. Fitting underfloor insulation would be beneficial, especially when done in conjunction with improvements to the heating system.

Simon Lewis 

Proposal