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Conversions - General

Basement conversion regulations advice

Am looking for advice on converting an existing basement into a spare bedroom in accordance with building regulations.
Current basement seems dry, has a radiator, light, powerpoint and top panel-opening window into covered light well. Existing rickety staircase down to the basement runs under existing main stairs to first floor.
Room size (excluding staircase area): Length : 360 cm Width : 350 cm Height : 205 cm
Width of window, i.e the actual opening in which the windown rests : 70cm wide x 125-130cm height
Staircase: Number of stairs : 11 Range of head height on stairs : 179 - 194 (most of them are circa 184) cm
Anticipated work:
- Lowering of floor (would this be required as current height is 205cm?)
- Appropriate damp proofing (Tanking or membrane? Any regulations around this choice?)
- Reconfiguration of staircase (what is maximum height we need to achieve to meet regulations?)
- Installation of egress window (is this mandatory?)

Thank you!

Many thanks for the information, Paul. Sounds more extensive than I thought. Can you advise on the depth needed to add insulation and a dpc to the floor? Since current head height in the room is 205cm, would be good to know whether digging will be needed and how deep. Thanks again!

4 Answers from MyBuilder Conversion Specialists

Best Answer

Yes, the basement has to meet building regulations, and this is not easy in a basement. The floor will need replacing to provide the correct insulation and a dpc. The walls will require tanking, there are several sytems that can be used, a typical one is the Safeguard system for example. The walls also have to be insulated. The stairs will need to be of the correct pitch and the head heigh must be no less than 2m. You certainly need an escape window, both for building regs and a safety issue, imagine being trapped by a fire in the basement. Because this is a bedroom it has to meet all of the building regulation requirements of a new bedroom, much the same as a garage conversion or a new extension would. You need to appoint a surveyor who is fully aware of all building regs (many are not) to draw up the plans for approval by building control. We use a surveyor who is also a building inspector, so we never get any problems, but this is by far the most important part, so choose the surveyor very carefully.


Paul Albright


Answered 19th Jan 2012

Hi, I'm turn a cellar into a bedroom on a hmo.
will it still be to regs for the window to be open onto the pavement at the front of the property as no front garden?


Answered 28th Oct 2017 above but fire doors will have to be introduced. Hall way area.and new room.


Answered 23rd Feb 2018

I know this is a very late answer
1) Before altering your basement check the water table in your area as you maybe opening a spiders web
2) So called tanking is a very dangerous way unless you have a company that gives you guarantees well established
3) All tanking does is transfers the problem some where els solve the problems before any of this work is done
Regards Chris


Answered 19th Feb 2018

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