Building’s Forum regulars offer their advice on problems. This week: extending a shared roof

Q: Shared mono-pitch roof

We live in a classic Victorian terrace house, two up, two down with a half-width kitchen and upstairs bathroom at the back. Over the years the kitchen has been extended back and to the width of the house, and we would now like to do the same upstairs to provide a third bedroom.

Our bathroom shares a slate, mono-pitch roof with our neighbours, and to make the changes the roof on our side will need to be raised and lengthened.

Before I speak to an architect, can anyone tell me if this is possible with shared roofs? There are no ridge tiles between the properties, so I guess the roof would need to be separated in some way.


A: The limitations of construction are only dictated by the number of pounds in your bank account.

You may or may not need your neighbours’ consent, but it should be possible, even if you have to demolish your house and start again (bit drastic) but it will all depend on price and whether that bedroom is worth it or if it’s cheaper to move.

Your choice. An easy way of answering for yourself is to see if any of your neighbours have done this - if they have, see if they can recommend their architect, as he will be familiar with the problems, area and construction type of your dwelling. Hope this helps.


A: Hi _awbp_ - welcome to the forum.

Firstly, get professionals to look at it for you. Find a registered builder in your area - remember personal recommendation is always worth its weight in gold, so if you know someone who has had recent good experience with a contractor that’s a good starting point.

You will need also to speak to an architect, possibly a structural engineer and various other bods - including our current favourite (not) topic on this forum - a party wall surveyor! You might want to gen up on the party wall act. Keep us in the loop. Cheers.


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