the first Certified Passivhaus in England, by Seymour-Smith Architectsthe AI PassivHaus

1st December 2009

A new phase of the build, as first fix electrics are now underway, fixing conduits to the floor for the power and data – these will eventually be covered by screed.

From the South, we begin to get a taste of how the complete building will look.

3rd December 2009

In the areas like this that will be in direct contact with the ground, a Sto product called Flexyl is applied, first to the substrate as shown here, and then onto the insulation, to adhere the insulation and to make it waterproof.

9th December 2009

The same treatment is used on the ends of the facades, where gabions will be up against the walls.

10th December 2009

Mesh reinforcement is used to give extra strength to this system,

shown here being smoothed into the Flexyl at the edge of the facade.

This render is in fact so impact resistant that with an axe, we were completely unable to dent it...

Meanwhile, Nick has been getting on with fitting waterproof flashings around the base of the kitchen garden walls. The white stuff isn’t snow – when the insulation is cut, it looks like an explosion in a beanbag factory. On top of the drainage layers shown here, there will eventually be gravel, decking and planters.

16th December 2009

Inside the house, we’re preparing for our airtightness test by plastering the few bits of perimeter wall which are blockwork, such as this one between the main entrance and the garage. The majority of the building’s envelope is precast concrete, which is inherently airtight, particularly when waterproofed.

Outside, the renderers are busy applying angle bead reinforcement to all of the corners.

21st December 2009

We’re a bit chuffed. Our airtightness test has just been carried out, and the results are excellent. We needed to achieve under a challenging 0.6 air changes per hour at 50 pascals (n50) to meet the passivhaus standard, and in fact achieved a fantastic figure of 0.2198ac/h @ 50pa. This may be the best result recorded in Britain?... To put it in context, building regulations require a q50 result of 10m3/h/m2 @ 50pa, and our equivalent q50 result was 0.23 m3/h/m2.

As well as the excitement of the airtightness result, there is also the excitement of having our fuse box installed...

and having the entrance area insulated. Is the white stuff frost or polystyrene beads?...

It is in fact both – but the next day, proper snow stops play and we have to close the site for Christmas. Still, on reflection, not bad for a year’s work...