Extension advice - Where to start?

Ripper

Ripper

Ripper

Soldato
Joined
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Newark, Notts
I'm currently considering an extension to my property but I'm genuinely a bit confused of what I need to do to get it moving. We've had two builders come round who have basically said they can do it, subject to proper calculations and planning being confirmed. But I don't actually know who to go to next and whilst I asked them questions, they wern't really clear and I'm wary of looking stupid. Therefore, obviously i'll ask here instead!

I've done a sketchup, current on left, what I want on right:



Where do I start? I believe it falls under permitted development due to dimensions but not 100%. Do I need someone to come and do professional drawings/plans? Who? Then what? When will the builder be involved again?

Any advice anyone can give would be appreciated! Cheers.
 
If you are extending out the back of anything that is an extension you'll need planning permission. It looks like the right 1/3rd of the house may be an extension so as you plan to extend out the back of it you'll need PP.

We are going through exactly the same process now. Below is roughly what you need to do:

1) Speak with an architect to draw you detailed plans of the exterior of the extension, work with them until you are happy with everything
2) <Optional> Go and sweet talk your neighbours, explain you'll be getting an extension here is the rough plan and details. Once you apply for planning they will all get letters from the planning office with the details anyway so if you get them onside before hand it makes it much easier.
3) Submit drawings to planning office via your architect. PO may come back with suggestions, demand alterations and take feedback from neighbours. This part of the process can take up to 3 months (and it likely will be close to that)
4) Once planning is approved you can legally build it, you have 3 years to get started (break ground) before the planning needs to be applied for again. As you can now legally build your plans you'll want to speak to a Structural Engineer who will be able to calculate the materials you need (such as RSJ's as it looks like you'll be removing load-bearing walls). Your architect will likely be able to recommend a SE to carry this out. You'll need to work with the SE as it will cost more to hide RSJs and they may need to make suggestions about beams and various bits. The SE will ensure everything is going to pass building control (who ensure the building is safe). Building control will often make a few visits during the build to ensure everything is being done as instructed by the SE. Building control do not concern themselves with anything to do with planning (which is about if you can legally build it), they are just making sure the right materials are being used and everything is safe.
5) Once you have the drawings (architect) and calculations (Structural Engineer) you can give these to a builder for a formal written quote.
6) Once you have picked a builder you can get started.

It's important to remember that planning and building control are two completely separate things, neither cares about the other. Architect and planning office is purely how the building will look from the outside and if you can legally build it. Structural engineer and building control are there to make sure everything stays up, is safe and properly supported.
 
That’s brilliant mate, really appreciate that.

Sorry the right third isn’t an extension, that’s just my lame sketchup skills leaving a line there.

Even if it doesn’t need planning permission is the first step still the architect?
 
Ripper said:
That’s brilliant mate, really appreciate that.

Sorry the right third isn’t an extension, that’s just my lame sketchup skills leaving a line there.

Even if it doesn’t need planning permission is the first step still the architect?
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For something big like that I would say yes (unless you feel you can deliver what they would - calculated drawings with exact measurements). Someone is going to need to provide extremely accurate measurements and drawings to the SE / builder. In theory even with a requirement for planning you can do it all yourself, but an architect is likely to know what you'll get away with, tricks to help get it passed and avoid any future issues.

Is any of the house an extension already apart from the little bit out the back that is being replaced?

Are you detached and would the extension go back further than 8m or be close to boundary on either side (I think it's within 2m)?

Could the extension potentially block any light for a neighbour?

If the answer to all of the above is No then it's unlikely you would need planning permission. In theory you could skip an architect if you feel comfortable designing and measuring everything accurately.
 
No part of it is extended no.

Detached yes. We’d been extending out in line with the edge of the section that would be knocked down (2.1m), so technically no further out overall.

It is within 2m of the fence, infact practically right up against it on one side. It could potentially block some light, although not much.

I had considered whether I could do the proper drawings myself to save money, not sure how much I could save by doing this though?
 
Find an architectural technician that’ll be less expensive. You don’t really need an architect for a bog standard extension.

Building regulation drawings can be pulled off standard readily available resources.

Structural calcs you can employ a local SE, BC will check them anyway. Could just be hand drawn calcs no need for complicated cad
 
Then you can send a pack to builders to price. Lots aren’t interested in taking the planning and SE risk so you’ll open yourself up to a wider range of builders.
 
Ripper said:
No part of it is extended no.

Detached yes. We’d been extending out in line with the edge of the section that would be knocked down (2.1m), so technically no further out overall.

It is within 2m of the fence, infact practically right up against it on one side. It could potentially block some light, although not much.

I had considered whether I could do the proper drawings myself to save money, not sure how much I could save by doing this though?
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You can go up to 8m back as you are detached with permitted development without the need for planning approval, however as you'll be going close to the boundary you may need it. There are also quite strict limitations of eaves height with you being so close to neighbours so you may have to have a flat roof rather than pitching it.

To build right up to the boundary the builders will need access to the neighbours land / garden so you'll almost certainly need to have a party wall agreement drawn up (which iirc can cost about £2k-£3k).

If it can potentially block light and the neighbour isn't on board and objects you may find the planning office insist on a smaller extension, or amending the plans - this is probably where an architect would come in handy as they will know the likelihood of certain things getting through and how to play the system.
 
Even if you are told it falls under permitted development, it may be worth getting a Lawful Development Certificate. It's similar to a planning allocation but confirms that what is being built is permitted. This will be useful if/when you come to sell as well as taking away any doubt as to whether its within the scope of PD.

Also, I would advise you get drawings made up for full building regs. This specifies the details of what's going to be built, which means you're able to get a more accurate quote from builders and ensure what is being built will be within the regs. There's always some elements of a build which cannot be predicted until you start - eg. Depending on ground conditions, foundations may need to be deeper than originally thought, but you can try and do as much as possible to avoid any surprises later.

Builders will always tend to charge much more for anything not agreed up front, as they know its almost impossible for you to go to anyone else at that stage.
 
Maccapacca said:
Find an architectural technician that’ll be less expensive. You don’t really need an architect for a bog standard extension.
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I respectfully disagree.

If you go to a "one man band", then I would absolutely insist on a qualified one. If you're going with a company, then an arch tech is OK to do the work as it'll likely be reviewed by a qualified arch.

I've worked with technicians, as an engineer, and the fact they don't meet the minimum standards imposed by ARB is telling. Poor design, poor management, poor communication, disappearing from the job wity no notice, etc. Its false exonomy At least if they are qualified you can expect them to meet a minimum standard of professionalism.

Same with an engineer; always go for a chartered one would be my recommendation.
 
Peerzy said:
If it can potentially block light and the neighbour isn't on board and objects you may find the planning office insist on a smaller extension, or amending the plans - this is probably where an architect would come in handy as they will know the likelihood of certain things getting through and how to play the system.
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One thing I noticed with dealing with architects is that they seem to want to get the drawings done and through planning and then move on. We found our architect was over-conservative and quite deferential to Planning. Of course Planning hold the whip hand, but on the other hand we got the impression that the architect (who we paid on getting permission granted, rather than by the hour) wanted to get the permission and close the project.

So how you incentivise the architect has a bearing on what you can get too.
 
We've recently had an two-story extension completed on the side of our house (I'm sitting in my new office right now :)). The steps in post #2 are spot on.

However, I was comfortable with drawing up the plans and took everything through planning myself. There was a bit of to'ing and fro'ing since we wanted to build over a mains sewer pipe (on our land) for which we needed separate approval from the local water company.

It's worth pointing out that our builder had their own architect and offered to do this for us, but he was also perfectly happy with the approach we took. One thing I would stress is that we found it important that you find a builder which you are comfortable talking with, and who is well known in the local area (for good reasons!). We had a few quotes from builders who we found intimidating and a little dismissive when we asked simple questions about the building process. The owner of the building company we went with was the nicest man you could ask for, and came around every other day to check on the build and speak to us about how things were going. I was comfortable with approaching him when issues arose or we had questions/ideas. He was also always available on the phone and email.
 
one thing i would advise is find out how deep you footings are.

i.e. dig a small hole by the house, see where you hit the toe, and how deep these are, and i would also dig a hole at the point which is furthest away and see how deep you can go! (i would recommend a ground auger for this)

you might be lucky and hit hard ground after 1m, or not find hard ground at all, i.e. your house could be on a raft / pillings

this could be the difference between getting to damp course level costing 2k to 10k
 
How does £300-£400 sound for full planning drawings? Got a guy coming around tomorrow and that’s what he’s quoted ‘depending on the complexity’
 
Ripper said:
How does £300-£400 sound for full planning drawings? Got a guy coming around tomorrow and that’s what he’s quoted ‘depending on the complexity’
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sounds cheap...too cheap.

Anyone that values their time to produce drawings etc would never be that cheap. Who is he? Employed/self employed ?
 
booyaka said:
sounds cheap...too cheap.

Anyone that values their time to produce drawings etc would never be that cheap. Who is he? Employed/self employed ?
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Friend of a guy that came recommended. I wasn’t enamoured by him on the phone but he’s coming around tomorrow so we’ll see!
 
Currently going through the process myself (2 storey side extension).

Costs so far are (including VAT):
Drawings to planning stage (including Measured Survey & Ordinance Survey): £1000
Planning Permission Application Fee: £231
Structural Engineer : £950
Independent Building Control (Full Plans + Inspection Fee): £660
Architects Drawings (for Full Plans): ??? - Probably about another £1000-1500

...and that's all before I get to pay for any bricks :)
 
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