March 2010

Sunshine and Showers

With the solar panels in place tiling of the southern roof slope started immediately.

For the first time in several months we had a clear run of good weather, which made things a lot easier.

On the north slope of the roof Simon started work on the dormer window while Keith got on with the battening.

The house has a 'catslide' roof, so it's asymmetrical, meaning one slope is larger than the other.
This house, near Urchfont Manor in Wiltshire, shows quite an extreme example

It's extremely unusual for a passivhaus to have a dormer window, as it's difficult to achieve the necessary levels
of insulation. Ours was specially designed at the University of Edinburgh, and uses super-high performance
Kingspan Kooltherm insulation, enclosed in a plywood frame.

As with the rest of the house, making sure this is airtight is crucial, and from inside you can see the
airtightness membrane already in place, waiting to be taped to the inside of the dormer.

Down below in the basement (or 'Mike's playroom' as our site workers know it) it was time to set up a temporary
workshop to support the electrical wiring operations.

We're using 'fire-rated' cable for all of the mains wiring. It's free of PVC, which we're trying to avoid using because of
the toxins produced during its manufacture. This cable is also double foil screened, reducing the level of electromagnetic
fields, which (some would argue...) will contribute to a healthier living environment. And it's a lovely red colour.

Many of the cable runs are in the basement, because inside a solid block
and concrete building there are very few places to hide them.

Penetrations through the floor into the house above have to be minimised,
and will be carefully sealed for airtightness once all the services have been installed.

The wiring is a major operation, which will carry on for several weeks in parallel with other work. The hall, stairs,
landing and conservatory will be lit by low-voltage LEDs, running directly from the 12-volt battery system which will
also power our rainwater pumps. This should be highly efficient, and give us some immunity from power cuts.

Initially starting indoors in case of bad weather, Simon has been busy building the green oak frame for our front porch.

Once outside it was assembled and jointed in the traditional way, using hardwood dowels.
The timber comes from the Ragley Estate woodlands, just 10 miles away, so one of our most local building materials.

With the porch frame complete the roof timbers were extended over it, and the north roof slope loaded with tiles to see
if there was any flexing or settlement of the roof structure. Fortunately all was well, so tiling could begin later.

Alongside all this, the garage has been progressing steadily, with the wood wool boards almost
in position, ready to receive the lime render coat which will finish the walls.

On the outside of the house, the timber i-beams are beginning to go on,
ready to receive the 300mm of insulation which will be packed between them.....

...they also form part of the window reveals, beginning to give an idea of a finished room.
Part of this bedroom has been rendered with sand and cement as the corner will house a service duct, so won't
be plastered. Because concrete blocks aren't airtight, they have to be either rendered or plastered to prevent leaks.

On the first floor some of the scaffolding has been removed to make way for the walls of the kitchen, toilet and office.
When the house is complete, the whole of the area in this picture will be open, and form our main vaulted living area.

What can you see through the round window today children?
It's Uncle Keith, working on the i-beams.

Here, all ready for the bricklayers, are the rest of our electric storage heater blocks.

Down at ground level, site manager Max keeps a close eye on progress.
He's obviously been doing some kind of research, as his nose is covered in sand.

Tiling of the southern roof is now complete, and looks great. Once the northern slope is finished, the ridge tiles can be installed.

The i-beams are now in place up to the western gable.....

...where Keith carefully seals any gaps.

Lizzie regards the front porch with a degree of suspicion....

..while up above, tiling has already started....

...accompanied by a little light drizzle.

The building's beginning to feel much more like a house now, but there's still a huge amount of work to do before it's complete.
A lot of this is down to the details, which are more complex than a 'conventional' build, and the specialist systems, such as
the rainwater harvesting and slow sand filter. And when all that's sorted out, we plan to decorate the entire house ourselves.

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