Advanced search

Should I build an extension?

(18 Posts)
StuntNun Thu 04-Apr-13 13:03:57

My house has two reception rooms (living room and dining room), big kitchen (20 ft long), three good size bedrooms, en suite shower room, bathroom and a WC. As we have three DCs and are considering a fourth we are looking for a house with an extra reception room and an extra bedroom. There is one such house in our street costing £85k more than ours although it also has a garage which ours does not. We like the location of our house, get on well with the neighbours, all the kids round here are similar ages to our kids, etc. so I was thinking about building an extension with another two rooms for less than £85k. I have spoken to next door about it and they have said they wouldn't oppose it if we applied for planning permission. We would be extending into the driveway to the side of the house but there would still be space for two cars at the front of the house.

But I honestly have no clue about whether it's a good idea in the current housing market. We have had our house on the market for a year now with no interest and if it did sell we would have to take about £20k less than we paid for it six years ago on a 100% mortgage. Does an extension sound like a good idea or should I persist with trying to move house?

Karbea Thu 04-Apr-13 14:03:22

I went to my local estate agents with rough plans and asked them roughly what the new value would be, maybe you could do that?

quoteunquote Thu 04-Apr-13 14:03:58

If you like where you live and your family are happy, building an extension sounds like a good idea,

do lots and lots of research, see what other similar properties in the area have done, find a decent builder, good ones are booked up far in advance and know where the good architects are , so talk to the good ones, find out how long you will have to wait for a slot, stick to timber frame and you will keep costs down.

and go totally overboard on the insulation, so it will not be expensive to run.

architectming Thu 04-Apr-13 14:26:28

What you have to factor in when moving is not just the £85k on the house, you will have to pay search fee, lawyer's fee, estate agent, stamp duty, removal company and some decoration once you moved in. That's why people rather have an extension than move house.

As a general rule of thumb, budget in £1,200 per square metre on any extension you have in mind, that will cover basic construction and not furnishing or bespoke details.

As mentioned in my other post, speak to an architect and find out what you can do, the RIBA currently is running a charity scheme in association with Shelter called Architect in the House. A qualified Architect will give you free advice for an hour in return for a donation to charity.


Good Luck!

Potterer Thu 04-Apr-13 16:38:49

I am in the middle of having a rear single storey extension built!

Are you detached or a semi? The things to consider are that an extension has to be seen as an extension, so you have to jut it back a bit or make the roof line a bit smaller.

Has anyone near you had a similar extension? If they have and it is recent then you can probably view the plans on-line, or visit your local council planning department and see the plans and nick any ideas.

If you like where you are then extend, and I say this as someone who went through the hell of moving house 3 years ago. We had no chain below us and no chain above us so just 2 houses involved and it was still stressful and costly.

It is best to have an idea of what you want and then contact an architect. Even though I knew exactly what I wanted we still consulted one. Plans are easy enough to draw up yourself. I am a fan of 1cm = 20cm on the ground, so 5cm on your plan would be 1m in real life.

StuntNun Thu 04-Apr-13 17:55:56

Thanks for the good advice. Based on that rough calculation Architectming it would be £54k plus extra for the foundations since we would need 8ft ones. Since the rooms would be a study and a bedroom we would only need to plaster the walls and put carpeted floors in so I can't see that adding substantially to the cost. I have signed up to the RIBA scheme so thank you for the link.

Next door built an extension last year so I guess their builder would be a good place to start for quotes. Most of the same design houses in our street have been extended but only single story out the back or loft conversion Potterer so I would be a little concerned about getting planning permission for a two-storey side extension.

I feel really clueless about all this. I'll start with the architect and go from there.

architectming Thu 04-Apr-13 19:46:13

StuntNun, that £54k will be a rough figure, but bear in mind you also have to factor in professional fees, such as planning application / architect's fee / building regulations application / VAT on building works etc.

Also, I always advice clients to have a contingency fund, around 10-15% of your budget to cover any emergency / changes. Trust me, when it comes to building on site, something always go wrong, or you suddenly realise you want to change something, that will incur additional cost.

I am sure your architect will be able to explain all these to you and thank you for participating in such a honourable cause.

Good Luck.

StuntNun Thu 04-Apr-13 19:51:43

Thanks so much, I'm actually really excited about this now. I realise it may not be possible to get planning permission but it's certainly worth exploring the option as our current best plan is to move to a house down the road that we don't like that much but had four bedrooms. Our house has a great layout and good-sized rooms, just not enough space for us. In the absence of any buyers it's all moot anyway. But DS3 can't stay in our bedroom forever.

racmun Thu 04-Apr-13 23:27:05

We're in a similar predicament. In the south east Quotes so far are £1400- £1500 per square metre for a single storey and about an additional 40% for 2 storey.

Having an extension is a major inconvenience but so is moving. Is the other house exactly what you want or will you find that you will need to do stuff to that anyway.

Thing is you might just fancy a change

StuntNun Thu 04-Apr-13 23:56:45

I messed up the calculations then, a 5.5 x 2.5 metre two storey extension at a rate of £1200 per square metre assuming 40% for the upper floor would be a ballpark figure of £23k. That's quite a big difference! I have almost that amount saved so I wouldn't need too much of a loan to pay the other costs and have a margin for unexpected costs. I can't believe I didn't think of this sooner. The house we are looking to buy isn't the best layout and or location. Ours is good for both bit too small and a bit rundown. But we could extend and make improvements to our current house for less than it would cost to move to a bigger house.

DIddled Sat 06-Apr-13 00:18:45

We are also considering extension over top of existing single storey- assuming as the architect thinks that the original was dug to allow for second storey, so saving us foundation costs. Not a huge space but asking a pathetic box room into a reasonable size room. Plus we are knocking thru kitchen diner. No ideas as to cost yet tho, but the costs of moving are prohibitive anyway 4 bedders are 350k - we don't need the space really as only 1 teenage DS. Two storey extension was approved in 1995 so hoping it won't be an issue- exciting times!!!!

DIddled Sat 06-Apr-13 00:33:05

Sorry just realised I hijacked your post! I meant to say speak to an architect - ours came up with stuff I never thought of- and discounted stuff I thought would work. Like you location f our house is spot on- we just need to make it work for us. Good luck! X

Yorky Tue 09-Apr-13 20:54:02

Potterer - that isn't always the case, we got PP for, and have started construction of a 2 storey side extension with the roof line a continuation of the existing one.

Its been so exciting seeing it grow from an idea to plans to revisions to getting the permission then talking to builders and work actually starting!
If you want to nosey its all here

Good luck

StuntNun Sat 27-Apr-13 11:10:43

I had a look at your extension progress Yorky it looks very impressive! Thanks to Architechming suggesting the Architect in the House scheme I have now had my initial consultation and we would be looking at £30-40k all in, as opposed to £90k for moving. So even if we went 10-15% over budget it would still cost less than half to extend than to move!

The next step: talking the husband into it! I don't think he can visualise how it will all look and fit together with the current layout.

Yorky Sun 28-Apr-13 18:54:54

We have the waterproof sheet in place now on the roof, and will have tiles by the end of this week!
So have had to think about all the details like where radiators, sockets and light fittings are going!
Can't wait till they start taking the internal walls down!!

architectming Sun 28-Apr-13 19:11:45

StuntNun, well done on AiTH. Good Luck with your extension!

AmandaGurney Mon 29-Apr-13 14:20:42


I've had some work carried out on my home recently. I was in a similar situation but needed 2 more bedrooms a study and extra bathrooms. I live in Balham and moving houses would have cost me almost three times as much as extending. I used a company called Builders GB they are good and have worked with my husband and a few of his pals for many years now. My husband is a property developer and buys, does up and sells houses in South West London. He's been using this company for around 15 years now and they take care of everything including Planning and Architecture. We purchased our house in the late 90's and wanted to stay here because of the schools and our neighbours. Uprooting and moving would have meant starting all over again. I think that if you have a choice then it's better to stay where you are established and know the local community because it takes years to get to know people properly. I just couldn't see myself moving : / it's worth getting in touch with these guys their web address is

Good Luck

Balham123 Thu 06-Mar-14 19:05:38

I live in Balham and have had two widely different quotes for an extension 60k and 91k

Its a wrap around.

The extension goes 4 metre out from the back of the house and extending to the side maes it 5 monts wide.

The side extension is 1 metre by 5 metres , I n btoh cases I have asked for bifolding french doors at the back and three velux windows

I would appreciate it if the previus poster could tell me what theirs cost?

Join the discussion

Join the discussion

Registering is free, easy, and means you can join in the discussion, get discounts, win prizes and lots more.

Register now