Hi all,

I may have missed something but couldn't find a recent thread on this. When I last thought about my extension/reno, it seemed that bifold doors weren't ideal with MHRV so I compromised on french windows.
A few years later, I'm actually building it and the builder is asking why I'm not having bifolds. (My green architect is now retired and I'm just trying to keep things simple now).

So I wondered where things were at now - is it possible to buy 3m bifold 3 g doors at a price that won't break the bank and are airtight? TBH, I don't want wood ones because I know myself and I know I won't maintain them. Builder is in love with aluminium, but I've also seen suggestions that the thermal break isn't as effective as it might be with consequent condensation, so a bit of me is heretically leaning to UPVC.

Thoughts, ideas, experiences & recommendations very much appreciated...especially so I don't drive my builder crazy with my indecision!

Tania

I'd be surprised if they weren't airtight when new if fitted well but there are a lot of seals that are asked to do a lot of work and are often exposed and I'd guess have potential for damage.

Our relatives bifolds in an exposed location that gets wind blown have been a real issue for them - they're about 15 years old now but they're problematic to the extent my uncle now gaffer tapes over the joins in winter.