What do I need to know about extensions

[Goldenperfume]

Hi

We are looking to buy a 3/4bed detached house that has scope to extend. How would we know if we would be likely to get planning permission for an extension? Are there things to look out for? Thanks.

Can you see what has been done on the road already as that should be a good guide.

Look on your council planning section and search by road name, you'll see all applications (granted or rejected) by street. You can look at similar houses in the area and see what has been allowed. The plan documents are on there as well so you can see what the extensions would look like.

Some councils will give pre-planning advice but may charge a fee for that.

@Sillybillymillyvanilly Yes that’s sometimes a good guide but sometimes when I’m looking I’m not so sure. For example on this road all the properties look different so not sure if an upstairs extension above the garage would be possible: www.rightmove.co.uk/properties/128402621#/?channel=RES_BUY

I’m not looking to buy that by the way but it’s just a good example of where I’m unsure about extension potential

This is not an answer to your question, OP but it is important. Many (maybe most) garages (built as garages) do not have strong enough foundations to support a storey being built on top of them, or to meet modern Building Regulations.

There is also the question of closeness to neighbouring properties and the need for party wall agreements. In the case of the pic you sent - I know that was just an example - a two-storey extension would block the side window of the neighbouring house.

Both of the above issues can be dealt with, but planning permission is not the only consideration when thinking about an extension.

Local planners will have their own rules for particular locations, but, just as example, in the pic you sent the houses all seem to have a similar degree of space between them. If the whole road has similar spacing, planners perhaps might not be happy to see one single house with a double storey disturbing the spacing pattern of the whole street. They might be happier to approve am extension at the back, or a single-storey side extension to replace the existing garage. But as previous poster says, the best way to find out is to look at what's already been allowed in the street you are interested in.

You can apply for planning permission or the pre-planning stage without owning the house. Obviously this incurs costs but it's cheaper than buying, then discovering you can't extend!

Potential purchasers of our neighbour's house did this as the estate agent was marketing it as suitable for extending and ours was already extended. They were turned down for planning so withdrew from the sale (and ended up buying our house!). Ours had been extended several decades earlier when planning rules different so you can't just assume you'd get it based on what neighbours have done.

It's bloody expensive - get at least three quotes.
The dust gets EVERYWHERE.

Oh and after the neighbour's sale fell through the estate agent put it back on the market still with the possibility of extending mentioned. Even though they knew it had been turned down for planning permission!

Just another word of warning - the cost of designing and building an extension has gone through the roof (no pun intended). We recently moved and were going to extend but with the way costs have gone, it now doesn't make sense to extend. We should have bought bigger as it would have worked out more cost effective than extending.

The initial estimate of 35,000 has now doubled. We've abandoned the project.

Has anyone had any recent experience of knocking down a garage and building a 2 storey extension, or reinforcing the foundations and would be willing to share cost per m2?

Honestly, just buy a bigger house to begin with.
Extensions were always incredibly expensive, and now they're double what they were 5 years ago!

Interesting to hear all your thoughts! I had a feeling we need to be careful and not assume it will be easy to extend, especially when it comes to properties that are close to neighbours, so useful to know I was right about that. Didnt know about garage foundations either!

In an ideal world we would get something that doesn’t need extending but it’s really hard to find properties with 4 good sized bedrooms (at least in the areas I’m looking in). The fourth bedroom is often very small. Sometimes see some good 3 beds that would be very affordable and give us the chance to save up for a few years before extending.

Based on one quick glance at your link, I would be surprised if you got permission to build over that garage. It's too close to the neighbour and would make them look too bulky, losing the gap between them. Google 'terracing effect.'
Also check the council's planning section on the website, there are usually design guides there (might be called an SPD).

We got some advice before we went ahead with our extension from the company we ended up using. The advice was free, might be worth contacting an architect?

We used hometales for our side return and loft in 2019, and would recommend them www.hometales.co.uk