BISF House External Facelift Info Wanted

BISF House External Facelift Info Wanted 1

Hi to all members, I just joined the forum and this is my first post(of many more to come in the future, i’m sure).

I’ve been living in a BISF house for about 10 years now, and am now in a position to have a full external facelift to the property, eg new roof, fascias, guttering/pipes, steel profile removed, re-insulated top to bottom and a smooth rendered finish to it all, along with ripping down the old side sheds(my converted utility room) and extending out a bit more and rebuilding it.
One of my first questions is about the insulating, am i right in saying that external wall insulation is the best way to go with this house, so not to cause any future condensation and steel rot problems???
if so the permarock system looks like a good way to go for the bottom of the house, but can it also be applied to the top(not being a solid wall) where the steel will be removed or am i looking up the completely wrong avenue??
Any info, comments, images, diagrams, costs etc on this would be greatly appreciated if possible.

Thanks in advance.


  1. Yes external insulation generally an superior solution to interior – but you pay for the liberty. The main reason is because it irradicates thermal bridging far more effectivly than would be achievable through the inside. But its main benefit is of course you can do it without completely gutting your house from the inside.

    In regards to the upper section, I dont know for definate but the few pictures I have seen of the process is battons are applied on top of the steel cladding which the insulation is then fixed to. There is no reason to remove the steel cladding, it is effective for its purpose and is firmly fixed, so generally I imagine the lower section was built out to get flush with the top section rather than the other way round.

    Costs, just for the external insulation Id hazard a guess at 15kish based on the going rate for materials and the kind of experienced trades you would need to complete this.

    Roof, facias, soffics, gutters etc will range from 3k to 10k+ depending on who you go with and your location. It can be done on 3k which includes the old asbestos roof being removed and disposed of.