As well as all the exciting stuff like windows and insulation (it’s all relative), every building needs a structure to make it stand up and this is where we have run into a wee snagette.
The current dutch barn that we are converting is essentially a simple roof lattice sitting on top of some steel uprights and topped with wriggly tin. While ideal for storing hay, this structure is a nightmare for thermal efficiency as it is essentially a cold, metal roof joined directly to the cold ground which together combine to form a supper efficient heat sink and condensation trap, both of which spell disaster for a super insulated, thermal efficient passivhaus.
That’s OK I hear you cry, just knock down the existing steel and replace it with a lovely wood frame like they do on the TV. Unfortunately it’s not quite that straightforward as the terms of our planning permission look quite specific and to cut a long story short we currently think the majority of the existing steel structure will have to stay in place.
To work round it we will need to build a new, more thermally efficient steel skeleton alongside the existing steel. This will then allow insulation to sit inside the current steel ensuring that condensation doesn’t form in the walls and any heat loss is avoided. Ironically once all this is finished and clad with wood you won’t see the old steel anyway but never mind.
A bit of a faff but manageable and properly spec’ed the steel will be re-usable, so in a couple of hundred years when our building gets recycled the steel can be used for something else like cutlery.
Turns out there’s a lot to this structural engineering lark.