Planning an Extension

platypus

platypus

platypus

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So, we're looking at extending. Basically, we want to do a loft conversion and to extend the back of our house to increase the kitchen/dining room space.

Early days so far and we're in the process of getting architectural plans drawn up. Any ideas what we should be looking for? Any advice from people that have gone through the process?

So far we've been quoted at £800/week for work that includes plans, checking planning permission and building regs and unlimited 3d models. He reckons 2 weeks work on average. Bear in mind that this guy comes recommended by a friend, and that counts for a fair bit in my books. But as we have no experience in this sort of thing, I thought I'd ask on here :).
 
Although £800/week seems good, I would preferred to have agreed for a fixed price what the exact scope of work would be i.e. up to obtaining planning permission. It gives them a clear objective and you know exactly what you are going to spend.

At the moment, the risk is that should they initially not obtain PP, they might keep charging you to address any issues for PP.

You want plans, elevations, sections, details. 3d models aren't really required in my experience other than for your own benefit.

Once obtained, you may need to appoint them again to manage the build (or a contractor if you prefer). You will also need the services of a structural engineer, which can be £40/h, to do the calcs, drawings and submit to building control for approval. By the sounds of what you are doing, could be £2k-£4k.

The engineer might want a site investigation done, to check how good the ground is to make that extension. That may be £1k or more.
 
single or double storey? A few people I know who got singles wish they had spent the extra on doubles or at least had the foundations made to be able to take it later.

No idea if that is even possible.
 
for the amount of work you plan to do the quote does seem about right. If the company i work for was doing the job i reckon it sounds about 10 - 15hrs work to get planning along with the same again for the building warrant drawings. As Sam says you'll need an Engineer to make sure the loft can be converted / identify what members need to be upgraded to take the additional loadings from being furnished if its not already got attic trusses of course. Knocking out to the new extension will be straightforward enough and likely done by linteling over with a steel beam or two.

Basic floorplans and elevations are all thats really needed unless you cant visualise how the extension will look then if they can chuck in a quick 3D model then so be it.
 
It's really hard to say mate without knowing your brief and location and how much involvement you going to want. I'm in no way advertising either but for smaller stuff like extensions we do them on fixed fees. Upto RIBA stage C - planning deposit is about £450-500. RIBA stage EF production information including building regs £650.

At that point our input is usually done but we then offer time charge consultancy during construction which is usually about £30p/h or £40 a site visit.

As I said its very very hard to offer much solid comparison without a brief. Be careful of time charge though because its open ended and costs can spiral.

Check their professional indemnity and public liability cover as well.
 
I'd definitely much rather have a fixed price.

I'm renovating a 2 bedroom bungalow at the moment which I'm planning to convert into a 4 bedroom 'chalet style' house. I've had two different architects look at it and they've both quoted me around £1250 to do all the plans ready for obtaining planning permission.

It's almost impossible to say whether yours is a decent quote without knowing exactly where you are and the size of the extension, etc. I recommend you get at least three different quotes.

I'd also echo what the others are saying regarding other costs (structural engineers, building control, etc) - make sure you add them into your budget!
 
Rough other fees include

Planning application fee - around £150

Building regs - around £450 including inspection fee. Consider approved inspectors as from experience they offer a better, faster service and can be cheaper than local authority.

Structural engineer - £450 - 600 again depending on scope of works.
 
LOAM said:
Rough other fees include

Planning application fee - around £150

Building regs - around £450 including inspection fee. Consider approved inspectors as from experience they offer a better, faster service and can be cheaper than local authority.

Structural engineer - £450 - 600 again depending on scope of works.
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Just to add to this list, as you are going to be working within the curtilage of the main roof for the loft conversion you may be required by the planning authority to carry out a Bat Survey by an approved ecologist which will be in the region of £300-500. The planning authority will advise if it is required for your proposal and they generally require them to be submitted as part of the application.

Your Architect should inform you of all this though :)
 
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ichabod crane said:
Just to add to this list, as you are going to be working within the curtilage of the main roof for the loft conversion you may be required by the planning authority to carry out a Bat Survey by an approved ecologist which will be in the region of £300-500. The planning authority will advise if it is required for your proposal and they generally require them to be submitted as part of the application.

Your Architect should inform you of all this though :)
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forgot about that bit.....and if they find bats.....you ****** The jobs we've had up in aberdeenshire they ask for a bat survey near enough every job! I'm sure theres part of the bat ruling thats actually impossible to adhere to as well :D
 
I got right up to planning permission approved then bottled it ... cost me around 4k but the rosy picture the architect painted wasn't so rosy when the engineer came and did a proper foundation study :(

Still would rather have known in advance than 1/2 way through so I would also recommend getting the engineer onboard early on as well.
 
One of my best friends in oakington does conversions rennovations etc and I will ask him which architects he recommends in the area.

I've asked him and will Pm you the message he sent me.
 
platypus said:
What do people think to companies like this: http://www.loftconversionscambridge.co.uk/loft-extensions.php? I'm not so keen because it seems a bit too convenient, but the other half found a few all-in-one services.
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Someone like that is ideal, they will do everything for you, my brother in law just had a massive conversion done and he knows sod all, just paid a loft conversion firm.

If you want to manage it yourself it'll be cheaper but if your clueless then contracting the lot out including planning would be your best bet.

Get three firms to quote, draw some rough sketches of what you want in size and plan and write a specification list, finishes, fittings, IT, electric, light fittings, bathrooms, brassware etc then get them all to price the same.

You could flip your thoughts and employ a Project Manager, I look at extensions conversions and refurbs, generate client specs and compare and drill down into quotes from contractors and architects, the most work I get is when people think they can tender the work themselves then pick the cheapest to find the builder hasn't allowed a raft of work that the client assumed was included then they are in trouble and need help.
 
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