On 25 Jan, 14:24, Tony Bryer wrote:
On Thu, 25 Jan 2007 13:52:16 +0000 Dave Fawthrop wrote :

Yes! Normal double glazed windows have the *facility* to be locked
totally closed or slightly open. IMO much better than trickle vents.
I'm not so sure. ISTM that on ground floor windows locked slightly open
is akin to a notice saying "insert crowbar here".

I would've thought it'd be just as easy getting a crowbar underneath
even a closed UPVC window frame - they're not the stiffest of
structures and indeed what with the rubber sealing strips there's
probably enough of an available gap to get the bar into without causing
distortion anyway.

I'm sure one of the main reasons behind multi-point locks on UPVC
doors/windows is simply because without them the structure as a whole
would be trivially easy to get into.

Mathew