Escape windows too small

[booky1]

Hello. I've just finished a self build and had the final inspection from Building Control which has highlighted a problem with 3 of my upstairs windows which are designated as escape windows but are too narrow.
They are side hung uPVC casements fitted with escape/easy clean friction hinges. The width of the opening in the frame is 455mm but the clear opening width reduces down to 385mm when the 70mm thickness of the open casement is taken into account - not the 450mm minimum required by the building regs.
Does anyone know if it would be possible to use the existing casements but change them to top hung? If my sums are right then to achieve the minimum opening area of 0.33 sqm the clear opening height would have to be no less than 734mm. The frame opening height on the smallest window is 830mm so the open casement can't intrude more than 96mm into the top of the frame. Are there any top hung escape hinges that could open this wide and leave the casement sitting this near to the top of the frame?
Any advice would be greatly appreciated.

 

[Gazman16]

I dont personally know of any 90degree egress top hung hinges. Even if there are I would estimate the opening to be at least 100mm smaller than the aperture (70mm of sash thickness plus a bit for hinge travel).

I have occasionally seen door butt hinges fitted externally which would allow a full opening but your still going to need new sashs made to have the locking gear in the correct place plus you will have holes from the old handles on the sides.

 

[crank39]

^^^ This

 

[booky1]

Thanks for your reply. I'm making enquiries with several of the larger hinge manufacturers. If they come up with anything new I'll post it back on here for interest.

 

[booky1]

Great news. A really helpful guy at DGS Leeds Limited suggested keeping the windows side hung and replacing the existing hinges with their Mega Egress hinges. He even sent me a pair to try. They open the sash until only about 25mm is projecting into the frame opening but they also throw the sash out clear of the frame which just gives me the necessary 450mm coming in at an angle.
Thought this might be useful info if you ever find yourself in a similar situation.

 

[Gazman16]

Cool. Might be nice if you could post some pics of the hinges when they are done and maybe a link to the product.

 

[booky1]

Hello. Just fitted the first pair of new hinges. They did the job and have increased the clear opening to the 450mm minimum I needed (please see attached before and after photos). The supplier was DGS Leeds Ltd, the hinges are called 'Mega Egress' and have a product code of F/SME12SH16.5.

Cheers

 

[phatboy]

I wonder why these aren't standard on all windows? Seems like a much better hinge design!