With about a month to go before work starts on site it makes sense to order the items with the longest lead times so they don’t hold up the build schedule later. In particular:

• The SIPs structure for the second floor walls and the roof, which needs to be ready to go on as soon as the cavity walls are up to second floor level. Since this is being contracted as a design/make package with the supplier (Sips UK) the detailed design work also needs to be completed soon in order that the thermal performance can be checked in PHPP and so that the load-bearing assumptions for the masonry structure can be confirmed.
• The windows and external doors, which have a 10 – 14 week lead time once all the dimensions and specifications have been confirmed. I’ve settled on using windows and doors from Europe’s leading Passivhaus-certified window manufacturer Internorm, located in Austria, supplied and installed by their leading UK distributor ecoHaus Internorm who are based near Stroud in Gloucestershire. While the Internorm windows are not cheap, I’ve looked at a few alternatives and I’m happy they represent the best value for money – both the build quality and the performance are excellent.

Placing orders for these sort of items means paying a substantial deposit. As with most of the building work, these sub-contracts are being managed via my main contractor. Since we’re not quite ready to sign the main building contract these initial orders have been covered under a Letter of Intent which will get subsumed into the main contract once that is signed.