rear extension quotes, deluded about expectations?

[masamune]

I am going through quotations for a single storey rear extension and some of the first figures have been well over my expectations. I now have concerns whether the quotes are just over the top or I am being deluded about my expectations...

I don't expect people to breakdown costs for me, just want to share some ballpark figures below and see what others think. Every project has its own merits, kitchens, bathrooms and other aspects of the build can increase costs drastically. So I am only focusing on the building cost which at the moment seems way too high. e.g putting the shell and primary finishes together, excavation, foundations, shell blockwork, plasterboards/skim, roof construction/insulation, then electrics/plumbing.

The place is a 3 bed semi off the inner belt of the M25, zone 6 in London. As a rule of the thumb I have allowed around £2000/m2 for good quality finish, I presume these figures to be inclusive of labour and completed interior plus VAT on top.

As an example, a neighbour in the area carried out a similar extension of 3.6m, mid-range quality with utility/WC area for around £60k+, the figure includes VAT and supplied materials. I cannot tell if it was on the lower end though.

Adding my extension spec below (pic attached),

The total footprint of the extension part is approximately 22 m2 (18 m2 encroached space) with the old galley kitchen split to WC/Utility around 5 m2.

View attachment 113544

• The shell is 4.0m (D)x 5.0m (L) with low pitched roof, interlocked tiles
  
• two large skylights (2.0m x 1.0m openings)
  
• The rear is mostly bifolds across the length for about 4m.
  
• The old galley kitchen to be split into a small WC and Utility area.
  
• To this you can add the removal of an old rear chimney stack and demolition precast garage, UFH and patio slabs.

No other major structural work afaik. Alley access available from the house side.

The bifolds, skylights, kitchen and appliances, tiles, paving, bathroom sanitary, light fixings etc are separate costs on my end.

I estimated figures would not exceed £50k inclusive of VAT for up to the primary finish and hopefully decoration for this extension size. I allowed for a good above average kitchen, so the total budget to be around £75k + contingency.

Am I deluded or the quotes are insane?

Note quotes exclude own costs above and not a full list of every spec, include supply and fitting for two small PVC windows and fitting of supplied skylights. Added some of the highest figures below the quotes.

Quote#1:

Total £55k+VAT (£66k)

Shell £29,000 + VAT
this figure includes foundations, blockwork, roof, plasterboard and skimming, K-render

Electrics extension+utility/WC £3,000
Plumbing £4,500
UFH £1,800
Decoration £3,500
Carpentry £3,000 (no idea what that is...skirting boards and architraves?!)



Quote #2 :

Total 63k+VAT (£75k)

£30,000 + VAT shell with plasterboard finish, skim and joinery, K-render, no decorations

Electrics extension+utility/WC £4,000
Above ground drainage/Hot&Cold water £2,600
UFH £3,000
Interior Tiling £2,300
Kitchen fitting £2,300



Thanks for reading!

 

[^woody^]

I don't know if the quotes are correct or not, but regardless they are mad considering that you are supplying those high value items.

 

[RichA]

Quoted figs above don't add up? What is missing? e.g #1 is £45k not £55k.

 

[masamune]

Quoted figs above don't add up? What is missing? e.g #1 is £45k not £55k.

Sorry should have made the figures more clear. It is not a list of compounded figures, just the total quote with some of the highest priced elements.
One of the quotes was around 10 pages long (which aside costs is great), but I thought to keep the already long post shorter before people give up on reading

There are no special requests or site related issues that would affect the standard cost. Other figures are like 1st and 2nd fix of things, the garage removal etc. within scope I described in my original post.

 

[John D v2.0]

Well, your extension is really close to what we just did.
Differences are we are having a second floor small bedroom, we're infilling the side and putting in 3 steels, and basically rebuilding the main roof. And 4.8m opening for glazing. We knocked down 2 full chimneys. And doing internal for frames and skirtings ourselves. We're in zone 4ish.
We had 3 quotes around 70+vat and 2 almost 100 plus vat. The windows are about 10k on top for 4.8x2.5 screen plus 4 standard windows and fitting.
We were similarly surprised by the elec and water pipework so elected to do that myself.
I think in the end was 3.5k+vat per metre.

So based on all that, I'd say your quotes are about right. And good luck with the project, just get stuck in to it yourself.

 

[masamune]

I think in the end was 3.5k+vat per metre.

So based on all that, I'd say your quotes are about right. And good luck with the project, just get stuck in to it yourself.

Thanks for the input! I think the figure you describe is a bit excessive. Perhaps you live in a more affluent area, at least I know that in my area £3,500/m2 would be unrealistic...

What is the size or m2 of your extension?

I received another quote around £40k + VAT region, may go a bit higher with some extras but that means figures vary.

Does your quote include or exclude the kitchen, what sort of figures are you allocating for it?


Bifolds and skylights are just under £10k for me with fitting, but I am looking at schuco which is not average quality.

I think it's time to talk to some neighbours and update the builder's list...

 

[John D v2.0]

Just go into it with your eyes open, it's a lot harder than you expect at times and I thanked god we had an architect and structural engineer to come on site and tell the builder what was right and wrong. And avoid extras at all cost, plan it all up front and get quotes and stick to it. Don't rely on your builder having a fair approach to extras. We had 2 structural changes ordered by the SE and we're still debating the cost with the contractor as opinions vary!
I really hope yours goes well! But get some professionals on your side first just in case.
Anyway ours is around 24m² added, the 4 windows and rear screen including fitting is about 10k. The kitchen I reckon we'll spend around 6-9k fitting ourselves plus flooring which will be I guess 30 pounds a square metre. Plumbing heating and electrics will probably come to about 1500-2000 for materials, again diy.
Good luck, keep your optimism, and remember you're handing over your life savings for someone to destroy your house and make everything you own filthy. And if it's winter you'll be cold too!

 

[masamune]

And avoid extras at all cost, plan it all up front and get quotes and stick to it. Don't rely on your builder having a fair approach to extras.

This is very true, I take it as the best piece of advice and yes I expect things to be tough. This is why I'm trying to budget for everything in advance.

Anyway ours is around 24m² added, the 4 windows and rear screen including fitting is about 10k. The kitchen I reckon we'll spend around 6-9k fitting ourselves plus flooring which will be I guess 30 pounds a square metre. Plumbing heating and electrics will probably come to about 1500-2000 for materials, again diy.

I imagine £6-9k is for the kitchen joinery + appliances which sounds about right for a good quality kitchen.

The problem with the figures is that I have reference from plumbing work, electrical and a bathroom in the past. For example the bathroom is one of the most expensive elements, mine is a little smaller than the current Utility/WC and cost me around £5k. This was for disposal of old, new plumbing, new electrics, tiling, fitting etc. I expect the WC+Utility work to be higher of course but we are only talking about 1m2 extra. So the figures I am looking at are a bit insane. Expecting more quotes in the meantime...

I was also quoted £3,000/£4,000+VAT for electrics when previously I had been quoted a similar figure for rewiring the entire house (before decoration).
I can imagine figures like this around but not on an average scale. The builder is probably subcontracting a reputable electrician, adding his commission on top. Even if there was a new mini CU for the extension, the first fix should be straightforward in a new built extension plus some re-wiring chasing for utility/WC. So unless there is some hidden extra I am not aware of, I find it a little hard to understand how it is so expensive.

Personally I will not be doing electrical or plumbing work of this scale myself (unless you are an electrician etc?), but I do want the work to done properly by someone competent and certified for many reasons.

Good luck, keep your optimism, and remember you're handing over your life savings for someone to destroy your house and make everything you own filthy. And if it's winter you'll be cold too!

So true!

Thanks again for your advice.

 

[masamune]

Oh well, I decided to give up on the project following long preparation and planning for about a year.

From around 7 builders, only 4 quoted, one under £50k, one just under £60k and other two well over £60k. All figures excluding VAT. The under £50k did not proceed for the simple reason builder was unwilling to discuss any detail, although recommended.

This was for labour, plant hire and building materials, removing a precast garage and converting old tiny galley kitchen to half WC half utility. Standard plumbing/drainage involved, with only UFH on extension floor connecting to existing boiler.

Only things I could add is replacing a 3m old lintel in rear dinning room leading to extension (one builder quoted this work as £1500 only) and a build-over to the foundations to accommodate the 6'' drain pipe under existing patio. I don't think the last two would break the bank or pose any challenge to a competent builder.

I would have thought this was a fairly straightforward extension job as builders themselves claimed. To me the labour/building cost for such a straightforward job appears incredibly high excluding top spec materials as tiles, kitchen/appliances and glazing. Let alone doing a return extension or a double storey....

/end of rant

 

[John D v2.0]

Just get the shell done, then take 2 months off work unpaid and learn/do the electrics/plumbing/kitchen yourself!
You'll save 10k+ and do a better job anyway.
And ditch the ufh and bio folds to save some money too.
If you want it, you can do it, just have to focus and know you'll lose a year of your life and gain a giant pile of tools!

 

[HERTS P&D]

Whereabouts are you? north or south london?

Andy

 

[pilsbury]

Its sad you've had to give up. You budget sounded very healthy to me, but it costs what someone is willing to do it for.

My budget is very small. I'm just a keen DIYer and intend to do my extension single handily. In the next couple of days I'll be uploading my progress so far (design and material calcs) in the project section for all to look at and tell me how unrealistic I'm being!

Building is surprisingly expensive.

 

[garyo]

It might just be bad timing. My limited sense from people trying to do the same is that there's so much money chasing builders that they can pick and choose their work when it comes to turn-key extensions and buying it in as a fully managed project.

 

[Nige F]

I always think of any work as a % of the "value" of a property. We all know about the London housing market. Ironically the county where the Londoners like to settle (Sussex) is the most difficult to get to London to work - If one was prepared to pay 3 hours @ full rates per day per man just for the travel time, + fuel and wear etc. then an army of builders would be @ your door. As it is it's easier to let the monied come to us and benefit from the skills here.

 

[masamune]

It might just be bad timing. My limited sense from people trying to do the same is that there's so much money chasing builders that they can pick and choose their work when it comes to turn-key extensions and buying it in as a fully managed project.

This is the conclusion I came to after this, also builders have a number of projects and will quote higher on those they put lower in their list. The cost of the project simply does not justify the figure for the location and property value. Last I received was a quote of 100k from another guy, when he said I should ditch the UFH (quoted 1.5k) and bifolds (5k with fitting) to save money. Thought he was having a laugh!!!

After taking all factors into account, the expandability of the property is limited and it is just not worth it. The figures are way out of proportion for the shell alone and the house does not have the capacity to offer much more in terms of room or space beyond that in the future.