Fire Escape Windows and Building regulations

Recently the query arose regarding clarification of the word “dwelling” and in particular where egress fire escape windows need to be fitted.

Firstly, the definition of dwelling” is a unit of residential accommodation which has either single person or family occupancy but with no more than six people. The word dwelling does not include flats or apartments.

Flats / Apartments are categorized as being a “building other than a dwelling house”. Therefore, it is important to note that should you have a development / project where windows are being fitted to flats / apartments then it is Building Regulation B, Volume 2 which applies in this instance and not Volume 1.

Where are Egress Windows required?

Ground floor dwellings

All habitable rooms (not kitchens) which open directly into a hall way which lead to the main entrance door do not require egress windows, however egress windows may be fitted if the client should want them. In this case the window must comply with the egress specification stated in the approved document. Egress windows will be required however for any “inner” rooms where egress is not directly to the main exit door.

Upper Floor Levels no more than 4.5m Above ground level:
All habitable rooms (not kitchens) within the upper storey of a dwelling which has only one stairwell must have egress windows fitted in compliance with the Building Regulation unless that stairwell is protected in which case no egress window will be required.  Using an Egress window that is over 4.5m above ground level is not viable as it is unlikely that if a fire should occur that the occupants will jump through and out of the building at such a height. Therefore the Part B approved document states: -

“The dwelling may either have a fire protected stairwell or the top storey of the dwelling is separated from the lower storeys using fire resistant construction materials and provide an alternative escape route leading to the main door.  If the dwelling has more than one stairwell which are separate then this is deemed as an alternative means of escape and therefore the ruling above for floor levels above 4.5m need not apply.”

What is the specification for an Egress fire escape window?

As stated in the Building Regulations, any window which is provided for emergency egress should have an unobstructed clear opening area of at least 0.33m2 and must have a MINIMUM dimension of 450mm high and 450mm wide. The bottom edge of the opening window should be no more than 1100mm above the floor level. The window should also be in such a position within the dwelling that the person escaping is able  to reach a place free from danger (i.e away from the fire).