House extension… where do we even start?

[ThePurpleFairy]

We’ve been wanting to do a ground floor rear extension (something like 4 x 3m) along with some internal rejigging for a good while. Never had any major building work done before so totally new to this.

I’ve seen various advice during thread searching, some saying if you don’t need planning permission then likely won’t need an architect (which I hear are pretty pricey.)

The main thing I can’t get my head around at the moment is, how do we figure out whether what we want is remotely affordable without sinking loads of money into detailed drawings first? I would have been confident that it would be affordable until reading the recent horror stories regarding spiralling building and material costs, now I’ve just no idea whether it would be feasible - but if possible would totally change the way we use our house and make it much better for us.

I have heard that some builders will do drawings, but then I feel like I wouldn’t then be able to take the advice of obtaining multiple quotes? Am I just overthinking all of this ?

Any advice from a seasoned ‘house extensioner’ would be very welcome!

First you need to know what you want. Next you need to check permitted development rules that apply to your property, a quick Google will answer. Permitted development doesn't need planning. Get onto Houzz the green building forum and other sights. Buy some magazines, Self Build, and Homebuilding and Renovation are pretty good.

Start looking for a builder or three, ask local friends for recommendations.

Architects are expensive, architectural technicians less so.

Depending on where you are £1500 per square meter is probably a good place to start.

Thanks so much, I already know pretty much exactly what to ask for (I spent all summer mentally remodelling), obviously assuming any obvious changes that me not being a builder may need to happen. But generally I know what we want, it’s just the actually making things happen which seems to be where I’m just feeling overwhelmed. I’m in the north so I was hoping that would go in our favour - £1,500sqm would be affordable but I’ve seen so many saying that is right out the window at the moment, so thought of costs is frightening me a little (a lot!)

Check the rules about party wall agreements. Easy to google and essential to know.

Architects are expensive because they guide you through all of this.

They know what the rules are and come up with good ideas.

They will also know reliable Structural Engineers and builders.

Oh I forgot to add that when I checked, the extension size would be under permitted development and also we are a detached house

We couldn't get anyone to ballpark without detailed plans and weren't willing to sink the funds into them having done that before at a previous house and been burnt.

Appreciate that doesn't help you! I think one thing to be very clear on is how much rejigging of the existing house there would be and whether realistically any of the rest of it would be damaged (hallway/garden/driveway are the obvious) when factoring in how much needs doing. You could go for an architectural technician if you are fairly sure already of what you want, was cheaper the last time we used one.

Previously we just invited a builder round, who was a friend of a friend and he gave us some good ideas and rough costs. We went from there

Being in the north doesn’t automatically = cheaper. Ie building in Cumbria is mad expensive because bad road connections make moving construction equipment and materials much harder.
Personally in the current market id budget for closer to £2k per sq meter

Definitely not as north as Cumbria we are in the north west.

I’ll wait until the new year and then I’ll look into an architect technician. I will also try some builders (don’t know any personally unfortunately).

The internal remodelling is mainly knocking out walls to make better use of the space. I know this might need steels etc

Honestly, unless it’s really urgent if wait at least a year. Prices are astronomical just now. At least £2k/m² for very basic finish

@Bushkin it’s exactly this that is putting me off. The thing is, are they ever likely to go down again? I worry that I would wait for the costs only to increase further

I think an architect is a good investment. They are trained to come up with ways to make the space available work best for you and guide you through the process. I don’t think they are all that expensive in the grand scheme of things.

So much of prices at the moment is to do with the instability of the prices of materials even if they stay high if they stabilise there won’t need to budget for the risk of them hiking mid build.
If you think you’ll need steels at least £2k /sq meter. It’s insanely expensive at the moment.

We are just staring out.
We tried to get a feel for a good builder. Non were interested without getting proper detailed plans.

So 1st job - get plans done.
We needed planning permission which is still waitron on after the local council requested an extension to the 10 week deadline, then went over that due to the sheer number of planning applications in.

So once these are approved our next step is getting 3 or 4 builders in to get quotes additional ideas.

We are the same OP, wondering what to do., do we wait and the prices keep going up, which is a possibility or just bite the bullet and decide if the cost they give is worth it to us. If it goes down after that it's pretty irrelevant then.
The builders we original spoke to, said we were looking at about 8 months before they could start from the date of quote. That's how blooming busy the builders are around here at the moment

I'm thinking of doing similar to you OP, but will also wraparound from the side, so it would be helpful to know roughly how much architects are. So on a build of £100k would an architect be more likely to cost £1,000 or £10,000? I have no idea!

Not seasoned but currently tendering for our first extension.
I was a bit clueless, spoke to some neighbours who'd had a similar build & decided to use an architect. So far full plans by the architect & submission of planning application, plus structural engineers drawings and calculations for the steel beam, have come to just over £3000.
It's quite good as I have plans and a specification to ask the builders to quote for so they should be quoting like-for-like, & have had some guidance on what is realistic and doable, and the architect also put us in touch with some builders they've worked with (we have a couple of recommendations from neighbours too) to get quotes.
Personally for me it felt like money well spent, but other people may be happy without that guidance.

There's a great group on Facebook called Planning Geek. Lots of professionals on there answering questions free of charge. It's well worth a look - great to see all kinds of scenarios from can I do, how do I do, permitted development, even tree protection orders. I love it 😁

Given the amount of space and value you're likely to add to your house, that sounds pretty reasonable to me too @AwkwardPaws27.

Ugh. We went through this recently. Tried to do things properly by hiring ‘architectural consultant.’ He was beyond incompetent (wrong measurements etc) and charged us more than architect woild have done. Plus lied about us needing planning consent so that we’d hire him for thousands more to do separate planning application drawings (we did).

And yeah the project cost four times the architectural designer’s ballpark estimate 😡

Trust no one is my advice to you!!

But as to where to start. Phone your council’s building control department and ask if they can suggest architects / builders who don’t cause problems. Our building control dept said they love to do this as part of their service - they aren’t just there to check the finished job, they want to help the build go well!

Go on local FB groups / mum networks in your area and ask about for people who’ve been happy with their builders.

Do a LOT of googling looking for negative reviews. If a builder / architect only has a few reviews, that’s a bad sign however great they are (they may bribe people to remove bad reviews).

Once you have some names, you basically have to get the initial drawings done by the architect, then get a builder to quote (which takes ages as he spends a lot of time calculating how much materials you need and current prices for them, and he won’t bother to do this unless he wants the job).

(Don’t rely on architect recommendations for builders, ours was taking bribes to recommend people.)

Then select a builder and wait for them to become available, which for a good builder should be 6-18 months. If they’re available now, that’s a red flag. Good builders always have queues of eager customers.

Thanks so much, some really great suggestions. Assuming I don’t need any planning permission, if I were to have drawings done and it came out unaffordable now, do drawings expire? Or could I say requote in another year

@Thinkbiglittleone

We are just staring out. We tried to get a feel for a good builder. Non were interested without getting proper detailed plans.

So 1st job - get plans done.
We needed planning permission which is still waitron on after the local council requested an extension to the 10 week deadline, then went over that due to the sheer number of planning applications in.

So once these are approved our next step is getting 3 or 4 builders in to get quotes additional ideas.

We are the same OP, wondering what to do., do we wait and the prices keep going up, which is a possibility or just bite the bullet and decide if the cost they give is worth it to us. If it goes down after that it's pretty irrelevant then.
The builders we original spoke to, said we were looking at about 8 months before they could start from the date of quote. That's how blooming busy the builders are around here at the moment

@ThePurpleFairy

Now your plans are over the government target for being approved in 10 weeks, it isn't in the council's interests to bother with your application now but focus on up coming applications near the deadline so the council gets a high average for plans dealt with in the timescale.
We had this happen and despite phoning every fortnight where it was just awaiting a decision and shouldn't be too long/ various people were on holiday/yes they have delays and other applications for larger developments are having to take precedence - basically every excuse under the sun which meant nothing happened further for almost 10 months, when eventually it was declined. We got in touch with a planning approval expert who said we should have appealed immediately it went over time.....we appealed the decision and it was passed.

@ThePurpleFairy - sorry forgot your bit.
Is there anyone local has already extended a similar house by a similar amount? Have a look in your council applications - you could crib the design ideas from that. Plans don't expire. Permission does if you've not started the build in I think 5 years.

An architect is a fabulous investment and also it’s about £2000 per square metre at the moment (at least!)

You need to think about a topographical survey too!

Good luck

Watch out for time limits on the permission when granted; my local authority now says you have to start work within 3 years, though it used to be 5 years.

@ThePurpleFairy the only reason that the plans or drawings would expire would be if there was a change to the building regulations. The building regulations determine things like depth of foundations, roof joists, wall thickness, insulation etc. A good technician will be aware of upcoming changes and incorporate these.