Sash, mock sash 2g, 3g, upvc, timber..

[lizzieuk1]

Hi all,

 

So currently scaring ourselves with the new build budget and trying to find a good solution for windows.

 

We have a georgian type build design, so sash windows looking to feature. However, aware of the poor air tightness and, it seems, lack of 3g availability for a sash. 

 

Wondering if anyone has any good solutions, not averse to a good mock sash in wood effect upvc, but are there any 3g versions?

 

Ideally not timber as, going forward and getting older, maintenance has to be a consideration.