Does anyone know anything about planning permission on a house that's already been extended?

[Loueytb3]

Want to build a orangery/poncy conservatory on the back of the house. Now before I get too excited and build it in my head I have come across a possible stumbling block.

Our house has already been extended quite a bit by the previous owners and has a 2 storey extension along the back of the house, plus a bit on the back of the garage. I have seen something online that seems to suggest that you can't extend a house by more than 50% of the original size and I'm worried that our extension would take us over that. However, I can't find a definitive answer on this from searching on the internet. Does this just apply to extending under permitted development rights? Or would the planning office just refuse if we went over the 50% figure.

We have a detached house and a pretty large garden (80ft) so even with this new extension, we would still have a lot of space outside.

I know I can phone up and find out but I thought I would see if anyone knew the answer.

If your house is in the Green Belt (or similar designation), an upper limit of 30% is usual, above which planning permission would be refused. This would be 30% of the volume of the existing house. There may be specific volume limiting policies specific to your area, which you would need to check with your Council.

The 50% figure relates to permitted development and is a limit for the curtilage (house and garden) i.e. what you can build without planning permission. In practice, this is rarely reached on your house type before one of the other restrictions comes into play.

We're in the process of doing a big extension on an already extended house. The council were fine as long as the final building looked OK. The architect talked them round re: some fussing over dormer windows. We are not in any street of matching houses or conservation area.

My DH is an architect. This is his answer:
This sort of thing can normally be done under your permitted development rights. See www.planningportal.gov.uk/permission/house for an interactive guide and more information.

However as you have already had a significant extension, this may have been used up within your permitted development rights. Most planners are pretty reasonable. Just give your local authority planning dept a call - they will confirm if you require planning permission. Typically the LA fees for this is £150 for a submission. You'll need to get suitable drawings.

In my experience, if the extension is single storey, mostly in keeping with the existing house and doesn't reduce your garden space below 50% of your total curtilage (land area) then you are in with a good chance of a successful application. Always worth showing your plans to your neighbours prior to submission to reduce the likelihood of objections.

Hope this helps. Good luck.

We are about to embark on the 4th extention on our house (our 2nd), we got our pp without any problems.

Ok, so I am certain we will not be able to do it within permitted development given the size of the extensions that have already been added to the house.

We're not in green belt or a conservation area. Although some trees are protected, this wouldn't impact on them as they are in neighbours gardens a distance away.

MissMajoriBanks - I've had a look on the local council's website and can't find anything specific relating to volume. I have however found a policy document that says that normally they would refuse permission for conservatories added onto another extension. The picture shown is of a house which has a single storey extension, and then a conservatory on the back of that. Ours would not look so out of place as we have a 2 storey extension already. Our neighbours also have a 2 storey extension so our houses are the same depth at the moment. The policy suggests visiting the planning office early on to discuss so its not a definite no but it does sound as though it may be an uphill battle.

drcrab - logic says that if the planning office are being reasonable, they would allow some form of extension as it wouldn't look out of place and we would still have a large garden. We will speak to the neighbours but there isn't much point until we are clearer on whether its even worth applying for planning permission.

Louey - the policy about conservatories on the back of another extension is probably to protect the neighbours against incremental development along the boundary than the appearance. I can't be sure without seeing the document though.

If your neighbour's house extends rearwards to the same extent as yours then it will be easier because only the extension beyond the rear elevation of the neighbour's house will be counted, with some leeway for distance from boundary. Every Council operates this policy slightly differently though (and they all think their policy is the best way of doing it!).

I spoke to the architect from the orangery company today and he doesn't think we will have a problem. He will talk to planning if we decide to use them.