Hiring An Architect To Draw The Extension Plans

Once we had agreed on the purpose and layout of the extension it was time to hire an architect to draw up the plans to be submitted for planning approval by the council (i.e. make a planning application). This was much more expensive than we realised, even though we had come up with the main plan ourselves.

Update: July 2015now that I am planning a loft conversion, I have discovered that it is possible to get the cost of the plans down a lot – I paid £775 for my loft plans and this is all I need! More on this soon.

Update: April 2018 I moved to a bungalow and am now building an extension. I did all the designs myself, for free! Find out how I designed and planned my bungalow extension here.

The Planning Application Stage

Architect Designs Planning Stage Drawing

Proposed Plans Ready for Planning Permission Application

The architect charged around £300 for the initial draft, then another £300 before the plans were sent for review by planning. We had to pay around £170 direct to the council ourselves too. After a couple of months he plans were fully approved. This process took much longer than expected.

The next stage is the building regulations. For this new plans are drawn up, and these detail the construction of the extension. These plans are more detailed. This stage also cost around £600 (£300 initially and then another £300 when ready to go to the Building Regulations office at the council). This process also took much longer than expected. Several changes were requested by the council and made (although we did not get a report of these changes).

Note that the initial plans had a smaller French door and windows, 4 roof lights, no wall in the utility and the kitchen is still along one wall. The main issue at this stage is the size and shape of the proposed extension.

The Building Control Plans

Overhead View of the Extension

The building control plans specified everything from the depth of the foundations (it gave a minimum and maximum depth needed, which is then decided by the building inspector on the first visit) as well as the type of materials needed for the construction of the new extension.

Once approval was given by building regulations we could then start to get some accurate building quotes. Until now builders could only give a rough estimate of the cost to build the extension as they did not know the type and amount of materials. However, as soon as building control have approved the plans it is all systems go, and the builders provided more accurate quotes for the job, and we then picked our favourite builder.

The architect provided construction drawings which are the same as the plans for building control but with more measurements included. As well as the drawing plans there is also a lengthy document which details every part of the construction, specifying strength and load bearing of walls etc.

Note that on the final plan the utility wall is added.

More Construction Drawings

Construction drawings which follow the building control phase

Rear view of the extension

Rear view of the extension, showing foundations

Kitchen drawing

Kitchen part of construction drawing

More like this in the Planning and Design section

  23 comments for “Hiring An Architect To Draw The Extension Plans

  1. van Luu
    November 21, 2013 at 12:24 pm

    Hello Jon

    Thank you for sharing the information. I find it very useful, in the particular the plumbing issues that you had. Congratulations, a very nice extension. It must have been a great feeling when the work was finished.

    For us, we have not had such joy yet and our extension is still about two years away, provided things go as planned, or maybe longer ;-). I am currently in the process of preparing for some building regulations drawings and the specification. Unfortunately, I have a bit of a problem of finding such information on the internet and have no ideas what the specification must include. My extension is very, very similar to yours, and I wonder if it is possible at all to have a look at your specification document – you refer to as “a lengthy document which details every part of the construction, specifying strength and load bearing of walls etc”.

    I am happy to pay a small fee for the use of your materials, if required.

    Thank you very much in advance.

    Kind regards


  2. Hasan
    May 19, 2014 at 7:06 pm

    Hi Jon

    We too are embarking on a very similar extension and reading through your notes page by page made me realize and understand quite a few things much better. Thank you a lot.

    I also wanted to find out if you could share the the more detailed construction plans” with me?

    I am just about to hire an architect for initial drawings but find it hard to imagine what exactly to aim for.

    Thank you again and be in touch.


  3. Jon
    May 19, 2014 at 7:28 pm

    Hi Hasan, unfortunately I cannot share the construction plans with you. You will discover this too, but the plans drawn up by the architect are copyrighted in their name, so they are the only people who have the rights to share them. Also, as a lawyer pointed out to me, if I gave you the plans and your extension fell down (or other unexpected disaster) I might be held liable.

    The best thing to do is decide how much space you have to play with, decide what you really want in that space, and then approach an architect. Believe me, you will save money if you have a clear idea of what you want in the first instance. Every time you ask for a new idea you will be paying more money.

    To be honest, the detailed plans really do not add much to what you decide to do anyway – it is for the builders to make sure that it does not fall over. Sketch your plans on paper or use a basic computer graphic tool. Measure up etc. Architects can only work with your ideas, the better your idea, the more likely you are to get something you really want.

    Good luck with it, I am really glad to hear that this blog has helped. My top tip: get a good builder and ensure that every part is done by an expert: your builder should get in a roofer, plumbers, electricians, window installers, floorers, tilers etc. Mine did too much themselves and the end result is not perfect.

  4. Paul
    June 7, 2014 at 9:34 am

    Hi Jon, good site with some interesting tips. We’re just speaking to architects now about doing an extension. Am I reading right – you paid the architect 1200 for the plans for planning and building regs altogeter? We’re being quoted 4750. And thankfully he’s not vat registered. Does this match with the quotes you’ve seen?? By the way what part of the country are you in?
    thanks, Paul

  5. Jon
    June 7, 2014 at 9:56 am

    Hi Paul, in England, all in pounds. I will have to double check the payments, but it was about that figure. Certainly nowhere near £4700 – that is way too high for a simple single extension.

    “he’s not vat registered” – and yet he charges £4750? 20 jobs a year will easily put him over the threshold.

  6. Jon
    June 7, 2014 at 10:04 am

    I have found the original quotes;

    “Our fees start at £650.00 + VAT for Planning application and allow the same for Building Control stage”

    “Council Planning fees will be £150.00 and Building Control varies depending on the size & extent of the work but allow in the region of £300 for the application and approx. £450.00 for their inspection costs when building works have commenced.”

    So, total (inc VAT) …. about £1650 for architect, plus additional £900 ish for building, applications, inspections etc.

    So maybe the total was closer to £2730. Still a long way short of £4750.

    My architect is in Essex, I could put you in touch if you are over this way.

  7. Paul
    January 10, 2015 at 8:53 am

    I would like a plan develop for my kitchen extension please contact me on (telephone no removed) as soon as possible to give me an estimation.

    Thank you

  8. Jon
    January 10, 2015 at 3:47 pm

    Hi Paul, this is a blog about my extension. I do not do extensions myself.

  9. Tom
    April 8, 2015 at 10:51 am

    Hi Jon,

    Publishing information like this is very helpful. I live not too far from you and would like the contact details of your Architect.

    Thanks in advance.

  10. Jon
    May 4, 2015 at 10:42 am

    Hi Tom, sorry, only just got this. I shall mail you. Bear in mind that the prices mentioned above are several years old now.

  11. Nicola
    August 11, 2015 at 10:47 pm

    Hi Jon,

    Thinking of doing a double rear extension on my parents property. Initial quotes for drawings for the planning permission are coming in at 3-4,000 with another 4-5,000 for the administration work and sharing plans with the builders once we have the permission. This seems a lot higher than the price you paid. Any chance you could share your architects details so I can find out what a ball price figure for the drawings should be?


  12. Jon
    August 11, 2015 at 11:34 pm

    Wow. “Sharing plans with the builders” – surely that is just making a copy, or sending an email …

    The fees can be much higher than what I paid for larger projects, especially if they are factoring in several design ideas before you make a decision. I always told my architect what I wanted. Also, remember that a good builder can change non-structural aspects on the fly – building control will be checking anyway. But £9000 still seems steep! I used A&P Designs.

  13. Kully
    August 12, 2015 at 5:50 am

    Our extension was granted under the neighbour scheme , but the architect /surveyor is charging £620 to include preperation of building regs and schematic drawings to the council . He has no said that an independant other company will do the building regs and i’d have to pay them (est £500) single storey extension 4mX10m

  14. Jon
    August 12, 2015 at 7:07 am

    Building regs is a standard fee with the council. You are paying for the building control team to approve the engineering drawings and then make site visits throughout the build. A good builder can manage this for you, so long as the plans and calculations are all done. Speak to your builder first, for a small job they might suggest issuing a 48 hour building notice to the council and managing it themselves. You still pay the same either way, although maybe Dave on architect akin fees.

  15. Theresa
    January 28, 2016 at 9:30 pm

    Hi Jon,
    I am living in a B listed building, I wanted to to replace an existing wooden porch type structure for a more permanent stucture.
    I had an idea of what I wanted but because the building is listed I thought I had better employ the service of an architect to produce the relevant plans in order to acquire planning permission etc.
    A representative of the company visited my property to carry out an existing survey of the house and prepare an Outline sketch proposal, two sketches were prepared and we discussed the requirements and I made some amendments.
    I was expecting to receive a CAD sketch ready to be submit for planning permission. However I received another sketch and Bill £964.80 totalling apparently15 hours work. The sketch wasn’t entirely what I had agreed upon either. With all this cost I was expecting to have the planning drawing/ scheme design and the preparation of an application prior to summiting for planning. But for that I have informed it will cost me a further £750 plus VAT and expenses.
    A further detail design to building warrant standard would cost me extra £900 plus VAT.
    I am therefore writing to ask if the fees are correct and the hours of work are correct. All total cost in the region of £3500 to make preparation for planning permission seems extremely excessive for a porch 3 by 3 meters in size

    I,look forward to your response

    Many thanks

  16. Jon
    January 28, 2016 at 9:56 pm

    Hi Theresa, it does sound a bit steep, but that is how some architects price up a job. Ideally, you should have been given a complete breakdown of all costs before agreeing to go ahead with the architech.

    Regarding the £900+vat for the “building warrant standard” fee, I assume this is for application to the local council’s building control, including the fee for the site visits?

    What you could ask for is one more drawing that will be used for both planning application and building control – there is no need for two different designs. The only issue is that if planning reject it, you have paid a little more (for the engineering calcs etc.).

    By comparison, for my loft conversion, one architect quoted about £2500 for planning drawing, engineering drawing and submission to building control. I found another who just did one drawing that was used for everything and my builder arranged direct with building control (you can issue a 48 hour building notice). The downside of this is that if building control pick up problems, you then need to get drawings re-done before work can start – and the builders are already on site. I had this problem with the loft! I will blog more about it soon.

    Did you get quotes from other companies? It might not be too late – if you have the sketch you can ask if they can produce an engineering drawing and use this for planning and then control. It might still be cheaper.

    March 16, 2017 at 9:51 pm

    Hi Jon,
    I am an interior designer and also an architectural technician/designer, Here’s something that may interest you or anyone else looking to have a loft conversion, extension or basement conversion carried out.

    I have set up a registered limited company but the new website is currently under construction and is not live yet, called “THE £99 PLANS COMPANY LTD”, as I have found a potential gap in the market where I charge £99 for each element such as:
    £99 for the Planning Drawings.
    £99 for the Building Regulations Drawings.
    £99 for the Structural Design + Calculations.
    £99 For the Survey and investigative work.
    £99 For the Design Access and Planning Statement and other associated documentation.
    All this for just £495 AND I COVER THE WHOLE OF THE UK.

    I am doing this because I feel that most fees are excessively too high and you may think wow I’m charging too little but hey no I’m not because I’ve developed a totally new technique and can still make a good comfortable living out of this and I care about my work.

    Also by trade I am a Plasterer/Screeder and have worked on lofts, extensions, garage conversions, basement conversions, retail shops etc since 1989 and I have good reputable builders who have carried out work to a 100% client satisfaction and because of my site experience this comes in very handy when I am producing the drawings as I believe a good architect should possess site experience as well, unfortunately I don’t know any architect that possess this attribute.

    I have virtually a 100% pass rate with the Local Authorities doing, planning applications, certificate of lawfulness, permitted developments, building control applications etc.

    I thought I would share this with you to get your opinion to see what you think.

  18. Dionne
    March 20, 2017 at 10:47 pm

    Hi Jon,

    I have just been reading your blogs and emails. Very useful so I wanted to ask some advice. we are planning some internal alterations taking down walls and converting garage with a possible small extension and have been quoted £1850 by an architect for drawing and submission to council. Then an additional 1800 for structural drawings in second stage. Is this too much or not or should we just go with an architectural designer who isn’t a qualified architect but can do drawings?

  19. Jon
    March 20, 2017 at 11:08 pm

    Yes, I might be too much. Hard to say really. First, ask the council how much it is to submit for planning, and to submit for building control approval. My advice – although some builders will say that all you need for such a project (assuming all is under permitted development) is to give building control 48 hours notice, it is often sensible to get approval first. But, drawings, calcs and approval should not come in at £3600+ for a garage conversion.

    Options: search for somebody local to do the drawings for you, and submit them yourself. For the regs / calcs, ensure that your contract with the drawings is that you pay when they are approved – so you don’t pay for plans that are not compliant!

    Or, find a home renovation company that does the whole lot and compare to price of getting done individually.

    You could hand draw your idea over a plan of your house (you can pay a surveyor a small fee for this, or get an estate agent to draw some plans …. and decide not to sell.. ) and ask in a building forum (DIYNot.com is great) what trades you’d need for the job.

    Many builders won’t quote until you have the plans though, so a bit Catch 22. It might pay to break the project down though. E.g. the garage conversion may only need a foundation for a new wall (or not) and not other structural work. Building control might just say “it needs to be 1m deep” and be happy with that. Some steel manufacturers apparently provide calcs for steels needed for windows – and some window fitters may help too. Taking walls down is trickier, depending on the wall.

    A surveyor is an important part for the internal work, and might be where much of the cost is – some modern homes have large walls that are not load bearing at all, and easy to remove – a good surveyor (who is also insured for their advice!) will be able to tell you.

    If you are unsure, a reputable company that does it all might be the best idea – but “free” drawings may mean more expensive package!

    Some builders also work closely with designers and engineers and may be able to put you in touch with somebody who charges less – but in these cases, make sure you get the plans as you will be paying for them!

  20. marieana
    April 4, 2019 at 11:05 am

    I am interested to contact Martin Steele re his £99 building regulation drawings. What are they? Do they include the foundation of the extension?

  21. Jon
    April 4, 2019 at 7:46 pm

    It was 2 years ago he posted, not really sure. But for foundations you don’t often need drawings – building control will inspect the foundation and either say they are OK or not deep enough. Only time likely to need drawings is if the ground is a bit iffy, and needs pilings etc.

  22. sue pearson
    June 29, 2019 at 1:55 pm

    Hi Jon Wow this is the site I have been looking for. I think I may have made a big mistake. We are having an extension (simple single storey box on the back of the house and there is a young graduate architect assistant who works in the planning office at work, I asked if he knew anyone that could do me some plans and of course he said he could . He came round and I showed him my design and measurements which I had already done. He asked me if I had any existing plans from previous work which I gave to him. He talked about charging 8% of total build cost which he said would be around £1800 excluding council cost of submitting plans but that he could include his services – as far as I was concerned this all included drawing plans for submission, then building regs detail plans and submitting on my behalf. It took him two months to produce the basic plans and during this time I had discovered that I did not need planning and that I could submit a prior approval form for a larger extension (it goes out 4 metres), and that the regulations have now changed as of 31st May. I informed him of this and said as it had taken so long I was OK with just having the plans for approval which I submitted myself – two months in and I was needing to engage builders and get approvals done as I want the works to start in July/August so that the build is done by December. I asked him no to do any more work and just let me have the plans and I would take it from there.

    He never gave me anything in writing and he is now saying that his bill for (£2,160!!!) was just for the set of plans and that the building regs part was a goodwill gesture – as he has also charged me £120 for the ordinance survey map which I could have downloaded myself for around £24 I’m not sure goodwill is even in his vocabulary.

    I am seeking other advice from my builder (who thinks the charge is extremely excessive). He has reckoned up that he has spent 72 hours on measuring and producing plans – I think this should take more like 20 hours for someone experienced on CAD.

    So it seems he is intent on charging for the service I thought I was getting but all I have received are some planning drawings. He did come and measure but he was also given some existing plans as well.

    Seriously regretting how stupid I’ve been – I am not intending to pay £2,000+ but want to make him a fair offer and come to some agreement. He has refused my offer of £1,000. He is a young and inexperienced guy who has been doing this as a side-line but wants to charge full architect fees it seems. Looking for your views on whether this sounds like a lot of money for what I’ve got.

    I have no problem with what he has done but he claims the plans cover building regs but I checked with my builder and they don’t as there is no detail on them at all – just the dimensions of the extension. No building reg specs at all. Help. Feeling a bit ripped off. I have already arranged with the builder re the building regs side of things. Don’t want to pay twice but also not sure this lad is experienced enough to do them as he doesn’t even seem to understand what Im asking for.

  23. Jon
    July 1, 2019 at 9:27 am

    Hi Sue, so sorry to hear this. It is tricky – without any contract or agreement in place though, I am not really sure how he can demand that much money. Refuse to pay on the grounds that the plans he produced are not satisfactory for what you ask for, i.e. building control submission. Ask your builder if he can manage the building control himself without plans – he might refuse as may not wish to expose himself to additional costs if building control demand something done differently, but if just a basic extension, you should be OK.

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