Fire egress windows

Katie V · 10-02-2025 09:47PM #1

Hi everyone,

I am building our new home here in Ireland and we just moved over from the UK. We are just getting started on the build. I had my heart set on using top-opening fire egress windows on the first floor because our design calls for tall, narrow windows (about 1500 mm tall by 1350 mm wide).

However, the Munster Joinery window man told me that we can no longer have them top opening and that they must be side opening windows. I trust his expertise and assume he is correct, but I have not found anything online that clearly says top-opening fire egress windows are not allowed.

I just want to be 100% sure he is right before I proceed. Any advice or confirmation from others would be greatly appreciated.

Katie

muffler · 10-02-2025 10:08PM

Im a little surprised here. Did your architect/engineer not supply you with a window schedule or indicate the openings on the elevations? Who is your project manager / assigned certifier? Depending on window design MJ would be correct but you really have to comply with the building regulations.

muffler · 10-02-2025 10:19PM

For fire escape, rescue and safety see parts B and K of the TGDs (Technical Guidance Documents) which can be viewed or downloaded HERE. Page 25 of TGD B is the relevant page.

Katie V · 11-02-2025 12:02AM

Thanks for your response, I appreciate it.

Just to give a bit of context….I’m the architect on site, and it’s a self-build. I recently moved back to Ireland from the UK, so I’m still getting fully up to speed with the Irish system. That’s why I’m focusing on my own house first before taking on any work.

Thanks for pointing me toward the specific building regulations page. I’m familiar with fire regulations in general, but my specific question is in relation to the ‘top-hung’ aspect. The technical document states that a fire egress window needs to maintain an openable area of 0.33 square metres, which a top-opening windows can achieve. So I don’t quite understand why they’re not permitted.Am I missing something?
Would love to hear any thoughts on this. Thanks again!

Gumbo · 13-02-2025 05:35PM

https://www.boards.ie/discussion/comment/123157326#Comment_123157326

They are for means of escape and rescue, rescue is key here as a fire fighter may need access while in full fire fighting uniform.

Bit, I do agree, I’m not aware of any stipulation that prohibits top hung windows once you are meeting the initial opening restriction of 100mm, and then meeting the 0.33 Sq. M requirement along with the minimum 450mm requirements. Once that ‘box’ can fit out the opening then you should be all ok.

The on,y issue with top hung meeting the Regmis that when opened fully, they extend out a bit so you have to stretch to reach the handle.

sydthebeat · 14-02-2025 03:27PM

i have a feeling the issue here is with the "800mm from floor level" regulation ??

are you planning on having the whole 1500 x 1350 window opening from hinges on the top?

if not, how much of the window will open?

"top hung" certainly ARE allowed, all you have to look at is velux GPL escape rooflights for examples.

eg: https://roofwindows.veluxshop.co.uk/velux-gpl-2068

muffler · 14-02-2025 05:13PM

https://www.boards.ie/discussion/comment/123157326#Comment_123157326

Top hung windows are unusual in a 2 storey house. Maybe there's an issue with the structural integrity of the hinges depending on size and weight of the openings and that's what MJ are alluding to. They are allowed subject to compliance with regs. Can you fire up a pic of your proposed elevations and people might be able to offer better opinions and views.

fatty pang · 16-02-2025 10:53PM

https://www.boards.ie/discussion/2058395643/fire-egress-windows

See attached. Although UK guidance it is relevant and clearly demonstrates the principles involved. Having retrained a few MJ reps, their level of ‘expertise’ is on a wide spectrum.

CNCD-049-Escape-Windows-Easy-Guide.pdf

fatty pang · 16-02-2025 10:55PM

Hard to imagine a fully equipped (wearing breathing apparatus) firefighter trying to squeeze through a 0.33m ope. They’ve been going up the stairs for many years.

Approved Document O has something to say about this and the guidance therein on enhanced protection from falling will hopefully be incorporated into the next revision of TGD K. On a related note it’s still stunning to see so many transoms of opening windows at 800-900mm above FFL in multi-story buildings going up in Dublin.

Gumbo · 16-02-2025 11:01PM

https://www.boards.ie/discussion/comment/123179027#Comment_123179027

They won’t be squeezing through the OPE. But they will be negotiating it with the occupant hanging out of it at times. It’s the same reasoning as the 1700mm to eaves requirements for MOE windows in pitched roofs (loft conversions etc).

fatty pang · 17-02-2025 01:57PM

I can’t imagine to many occupants would be inclined to hang around long enough to negotiate their departure from a house going up in flames or with smoke billowing up the stairs. Fire-fighting protocols consider windows to be a last resort for rescue, as distinct from escape.

The rational I was given for escape windows is that the drop when exiting unassisted is ‘survivable’ – typically but with possible breakages from first floor, probable but with possible permanent disability from second floor. Third floor and above, survivability would be unlikely.

One trusts that the OP will never be faced with such an unpleasant scenario and can safely enjoy a top-swing window and it’s inherent advantages over a side-hinged window.

Katie V · 17-02-2025 05:11PM

Thank you everyone for all your comments. I’ve since spoken to another window company, who said it was a bit of a ‘grey area’ with regards the top hung aspect, but that there was no definitive legislation banning it. For clarity, I’ve attached the elevation in question. I’m aware that the openings as I’ve shown them, are too big to be one pane of glass and would need to be split somehow. I was just waiting to get expert advice before doing so.

Gumbo · 17-02-2025 05:15PM

https://www.boards.ie/discussion/comment/123180534#Comment_123180534

It does and can happen, hence the specific regulation in place for it.

muffler · 17-02-2025 05:58PM

https://www.boards.ie/discussion/comment/123181318#Comment_123181318

I don't see an issue with those windows being top hung based purely on the requirements of the fire regs. They just about meet the minimum height off the floor to the bottom of the opening but you then have to factor in the guarding. Quite honestly they are way too big as a full opening and supporting or maintaining the escape area is going to put a lot of stress both on the windows and the purse.

You could consider a centre mullion to divide into 2 and use fixed or dummy transoms but ensuring compliance with parts B and K of the regs.

fatty pang · 17-02-2025 08:52PM

https://www.boards.ie/discussion/comment/123181318#Comment_123181318

Assuming the cill height is >800mm above FFL the size of those first floor windows are not a problem. Even with triple-glazing, readily available hinges (Spilka for one) will adequately carry the sashes. A center mullion will add cost and worsen the thermal performance of the window and most significantly, kill the view from within. Again, to maximise the view, consider tilt & turn windows for the ground floor to avoid ugly mullions & transoms. I’d assume all those window don’t need to be openable particularly the large one in the middle.

fatty pang · 17-02-2025 08:53PM

https://www.boards.ie/discussion/comment/123182065#Comment_123182065

That diagram is hardly supportive of the assertion that ‘a fire fighter may need access while in full fire fighting uniform.’

muffler · 17-02-2025 09:26PM

https://www.boards.ie/discussion/comment/123182065#Comment_123182065

"avoid ugly mullions & transoms" Seriously? You obviously haven't a clue about architecture.

fatty pang · 17-02-2025 11:08PM

https://www.boards.ie/discussion/comment/123182162#Comment_123182162

Did I ever claim to have a clue about architecture? Windows though….

Given the OP is an architect I have rightly or wrongly, but reasonably, assumed from the drawing that uninterrupted windows were the preferred option. You, somewhat patronisingly, are asserting the windows ‘are way too big as a full opening’. Nonsense but perhaps understandable if your window experience doesn't extend much beyond bog-standard plastic windows so beloved of rural Ireland. “They just about meet the minimum height off the floor to the bottom of the opening…but you then have to factor in the guarding”. The cill height meets the minimum height requirement and still guarding is required…. Seriously ?

Katie V · 19-02-2025 05:18AM

You very Rightly assumed! 😉

I spoke with another very reputable window company today (Rationel) and they said there was no problem with the top hung aspect. They saw no issue with the size of the windows either….the only issue was the price. I’ll have to make some compromises somewhere unfortunately.

Thanks again for all your advice. Very much appreciated 👍🏻

fatty pang · 19-02-2025 10:58AM

I might not have a clue about architecture but I do know how to listen.

Also no harm in asking Carlson and NorDan for a price. They get very competitive when they know you are pricing them against each other. When you’ve settled on a price from one, then go back to the others and say X has offered an additional ‘architects discount’ – they all have the facility. Pricing will also be seasonal – winter production gets the best prices out of them - if it suits your schedule. Good luck with your build.

Mellor · 23-02-2025 10:06AM

There's is no compliance issue with top hung windows, the requirements are restrictions are the same. MJ were likely referring to the fact that they're own top hung windows would not be compliant, which is very different.

I see no reason why those windows can't be single panes. Just need the hinges to hold them. Much bigger windows are produced often. But FWIW, I don't think being side hung changes the aesthetics (when closed).

Fire egress windows

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