There will always be clients who are genuinely in front of the curve, who surprise us with their forward thinking.


Whilst we are exploring different ways to use materials to produce energy efficient buildings, we need truly inspired clients to see those ideas realised.  This is the case at this house in Bridgewater Drive in Northampton.  Just over 10 years ago we completed the ground floor remodelling of our client’s home, late last year they approached us again and simply asked how they could reduce their carbon footprint.  

With this brief, we thought about applying the concepts used in Passivhaus Retrofit to the remodelling of the house, but crucially before we started, we needed to establish a starting point for our designs.  As 40% of heat loss from an existing house is normally lost through air leakage, we started by trying to establish where the air leakage in this building was occurring.

Thermographic Survey

Image 1. Heat loss through dormer junctions.

Thermographic Survey

Image 2. Heat loss through corner of brickwork.

We regularly air test new houses and industrial buildings but there is currently no requirement yet under the Building Regulations to test existing houses.  We contacted Melin Consultants, who regularly test our buildings.  The survey was carried out by Jamie Best who had carried out extensive research into sealing existing buildings at the Building Research Establishment in Watford as part of his MA studies.  This was the first time Melin had been asked to test an existing house.  Using a combination of positive and negative pressure tests, the use of a thermal imaging camera and smoke tests we were able to build up a thorough picture of how warm air was able to escape from the building

This evidence will now help to inform us where to apply the air tightness measure that we use on our new Passivehouses.  If that is 40% of the heat loss dealt with through air tightness, we’ll tackle the remainder through added insulation measures that will be incorporated in the first-floor remodelling of the house.

Thermographic Survey

Image 3. Share if you see the cat!