Extension costs

[a1ex2001]

No, what i wanted to hear was more discussion on the costs per square metre more than someone charging me 3k for a bi-fold door then announcing its in the ballpark because i charged you 3x the actual cost of a door. You essentially arrived at the same figure as the previous builder by jacking up prices of items which i already had costs for, had you announced from the beginning that you charged 2k per square metre and left out the fact your massively overcharging for other items and the fact you need to overcharge to justify your middleman status i would have probably taken your assessment constructively.





I'll qualify that psd99's post mentioned 1000-2000 per square metre so of course on the upper end of that id be in the realms of what the_r_sole estimates, furthermore i am quite happy to be flexible on items of lantern windows (my architect advised i source it myself anyway) I was always curious of the costs of bi-fold doors considering unscrupulous people such as the_r_sole wants to charge me 3k for one door and another builder wants to charge £900. If i only got quotes of £3k for a door id obviously make a decision to have a cheaper kind of door installed or a smaller opening, tiling and kitchen i also accept but the builder quote i got for 34k + VAT didn't even include that. I don't have any large patio doors just the internal folding door and a standard pvc door to exit into the garden.



You could be correct there, i have mostly been contacting via email due to times i am available not being normal hours for calling people (eg. I just woke up.) I also thought since i have a limited amount of paper copies and i can send .PDF files to any builder that requests them i believed i could give them more of a impression of the job before having them visit and get them in paper form, i expected at this point a certain level of people not bothering to respond but not around 80% of people contacting. Judging from builders responses i don't think they use desktops and mostly just reply through mobile phones. I'll see if my wife can start phoning them up as she is awake at a more humane time.

A 30k plus investment maybecworth interupting your sleep for after all any builder worth his salt will want to meet you and see the place before he quotes and when they are working sleep will be impossible!

 

[Hedge]

Hahahaha, I don't charge anyone anything - I'm an architect who tenders domestic and residential projects as a day job, I was merely giving an overview of what kind of costs we see being returned all over the UK for this type of work, without knowing the exact spec of every bit of your specific project, the area you are in etc it's impossible to say why the costs returned was what it was - it's very easy to spend 3k on bi-folds.
There's no point in trying to discuss something with such an expert. Enjoy annoying the hell out your builders and running way over the original guesstimates you have.

Where are you based?

We want to do a similar extension to what the OP is proposing. A single story rear extension onto a 1930s semi.

I've had one quote from an Architect but I think it seemed a bit steep. Do I need an architect for something as common as this? (people in street seem to have done similar build). Would a technical drawing type person do an adequate job?

 

[the_r_sole]

Where are you based?

We want to do a similar extension to what the OP is proposing. A single story rear extension onto a 1930s semi.

I've had one quote from an Architect but I think it seemed a bit steep. Do I need an architect for something as common as this? (people in street seem to have done similar build). Would a technical drawing type person do an adequate job?

Based outside Glasgow, but got projects all over at the moment - if you've already had a quote that you think is expensive I'm willing to bet that we wouldn't be any cheaper!
You don't need an architect, there are plenty of very competent technologists/technicians out there - if you use an architect, you will have someone that is a member of a professional body that should give a professional service (and carries the relevant insurance).
It really comes down to what you want to do and the previous record of the designer, we deal with lots of extensions in conservation areas, listed buildings, sensitive countryside, which need a good amount of thought and justification against planning policies etc. A good designer should be able to give you more than you asked for, or more than you've thought of yourself - spending more time (and money) on careful, considered, design should give you the best return in the long run...

 

[D.P.]

What i have listed above is the complete detail i was given in regards to the quote. Which is why i am asking for some informal suggestions on what i am missing in my own estimates.

I was curious to why when im told 900 for bifold doors and 1200 for a roof lantern from one builder and you tell me its 5k for the 2 you can understand why i might be dubious to your claims.

I have been attempting to get other quotes but the process is taking its time so far out of 8 builders contacted 4 have responded and only 1 actually visited and quoted. I knew id get a quicker response here rather than track down another 10 builders for a quote.

If an overwhelming consensus advised me that 40k is a normal price then ill happily accept it. I was more interested in what others may have paid or had family or friends pay and a possible response on finished quality in regards to value. Perhaps even people on this forum might know a reason the job might be undesirable (eg. Busy periods or the demolition work) and why getting quotes for the job is difficult. In such a case i could make amendments to the scope of the job to attract more quotes.

The reason the other other builders haven't contacted you is that they are busy with lucrative contracts. Expect them to charge higher since it is likely a small project for them

 

[ash_scotland88]

Bit of a thread hijack, seeking advice from r_sole.

We're looking at doing a double story front extension, filling in the gap of a fat L shaped house.
Side goes beyond current elevation by 0.5m and front on ground level will do the same by 0.5m. So front size will be 3.5mx3m and first floor is 3mx3m.
RSJ about 2.5m ground floor to knock through from kitchen. This is to creat a dining space and a bedroom above.
From experience any idea of cost in a range.

And from your experience is it cheaper for a new roof over it or extend the current pitch line to square off, cover the leg of the old L shape. Really don't know how to explain it but I expect it would be the first option while the second is visually cleaner and more refined.

 

[the_r_sole]

Bit of a thread hijack, seeking advice from r_sole.

We're looking at doing a double story front extension, filling in the gap of a fat L shaped house.
Side goes beyond current elevation by 0.5m and front on ground level will do the same by 0.5m. So front size will be 3.5mx3m and first floor is 3mx3m.
RSJ about 2.5m ground floor to knock through from kitchen. This is to creat a dining space and a bedroom above.
From experience any idea of cost in a range.

And from your experience is it cheaper for a new roof over it or extend the current pitch line to square off, cover the leg of the old L shape. Really don't know how to explain it but I expect it would be the first option while the second is visually cleaner and more refined.

where are you based? Something like that I'd imagine you are into the 30k bracket but depends on a lot of things, does it have a lot of glass or conservation area etc? (if you are looking at small windows, basic level of finish you can probably get it down a bit from there)
The roof question really comes down to the best detail rather than the cheapest way of doing it, depending on your location, if you get driving rain etc you just need to make sure the flashing details are doing properly to reduce the possibility of any leaks

 

[ash_scotland88]

where are you based? Something like that I'd imagine you are into the 30k bracket but depends on a lot of things, does it have a lot of glass or conservation area etc? (if you are looking at small windows, basic level of finish you can probably get it down a bit from there)
The roof question really comes down to the best detail rather than the cheapest way of doing it, depending on your location, if you get driving rain etc you just need to make sure the flashing details are doing properly to reduce the possibility of any leaks

Edinburgh, cut through road (busy rush hour) where many people have done a side extension on different property styles and a few on the same style as ours. One neighbour has done similar to ours and has went for the cheaper option of roof, but no idea of actual extension date. Glass wise it'll only be two windows and turning an old window into a door, although windows would be quite large to keep proportions at 2.3m x1.3m (going from memory when I measured up shutters.
There are further plans to recast stairs to move door in current lounge/dinner, or maybe even move walls about too but without seeing property it's harder to explain.
But 30k is pleasing to hear. We had one architect around for a visit when we were set on a rear extension (glass, bifold etcs) and internal layout change and he thought it would be 50k+ for a 4m by5m extension.

 

[the_r_sole]

Edinburgh, cut through road (busy rush hour) where many people have done a side extension on different property styles and a few on the same style as ours. One neighbour has done similar to ours and has went for the cheaper option of roof, but no idea of actual extension date. Glass wise it'll only be two windows and turning an old window into a door, although windows would be quite large to keep proportions at 2.3m x1.3m (going from memory when I measured up shutters.
There are further plans to recast stairs to move door in current lounge/dinner, or maybe even move walls about too but without seeing property it's harder to explain.
But 30k is pleasing to hear. We had one architect around for a visit when we were set on a rear extension (glass, bifold etcs) and internal layout change and he thought it would be 50k+ for a 4m by5m extension.

yeah, large windows + in edinburgh is going to bump you up a good bit (when I worked in edinburgh we rarely saw anything come in at less than 2k per m2 and that was a couple of years ago now) - I know a guy based in portobello who does a lot of small scale stuff in Edinburgh, can trust you his details, probably give you a more accurate costing in your area

 

[ash_scotland88]

yeah, large windows + in edinburgh is going to bump you up a good bit (when I worked in edinburgh we rarely saw anything come in at less than 2k per m2 and that was a couple of years ago now) - I know a guy based in portobello who does a lot of small scale stuff in Edinburgh, can trust you his details, probably give you a more accurate costing in your area

That would be good please as we're just up the road from Portobello. We plan to tender the build out to three builders, although one guy I wanted to offer it to may be too busy working for a house builder these days.

Meeting again with architect on friday and now we have a better idea on what we want hopefully plans shouldn't be far behind. I think gone are the goals for done by christmas especially planning is now required but the other half works as one (commercial) it's just down to the inept council.

 

[the_r_sole]

well, if you already have an architect involved, wouldn't want to step on any toes!
If you need planning and building warrant from Edinburgh I wouldn't plan on any completion date until you have the paperwork, they are slow at the best of times although I believe they now have other councils processing the building warrants as they don't have the staff!
Are you in a conservation area or anything? trying to think of comparable jobs I might have done... You can access the old drainage records so that will tell you if you've got potential for a substantial bill in there, but planning in edinburgh conservation areas can make things a little more expensive

 

[ash_scotland88]

well, if you already have an architect involved, wouldn't want to step on any toes!
If you need planning and building warrant from Edinburgh I wouldn't plan on any completion date until you have the paperwork, they are slow at the best of times although I believe they now have other councils processing the building warrants as they don't have the staff!
Are you in a conservation area or anything? trying to think of comparable jobs I might have done... You can access the old drainage records so that will tell you if you've got potential for a substantial bill in there, but planning in edinburgh conservation areas can make things a little more expensive

Any advice is greatly appreciated, we picked him due to bouncing loads of design ideas off us and felt the most engaging from that aspect with our first idea.
No conservation area, 1950s "pebble dash" with red brick construction from what I can see. There's about 6 group of semis (12houses in total) of our design and we are the last house not to have any extension work.

Let me see if I can PM you details if you're really that interested.

 

[the_r_sole]

Yeah, drop me some details

 

[Jez]

the_r_sole;

When you mention your pricing estimates above, do you include multiple floors in the square footage?

I am currently in planning for a 7.4m*3.5m*2.5 storey (2 full floors plus roof accommodation with velux windows) built from local stone (Cotswolds, England) which is more expensive than brick and random in terms of size so bricklayers dont like it.

I have a shell price back (i dont need any internals, or windows), and am awaiting another one - but i wondered ballpark how you would price this?

 

[platypus]

I suppose it depends on where you are in the country. You wouldn't get a builder out of bed for that here .

 

[Kol]

I wanted to extend our back bedroom (single story) by about 1.5metres (the room is 3m x 3m) so what's that, 1.5m x 3m(?) and the quote we got was £30k (London). It's nothing special, at all. Just a basic extension :/

 

[the_r_sole]

the_r_sole;

When you mention your pricing estimates above, do you include multiple floors in the square footage?

I am currently in planning for a 7.4m*3.5m*2.5 storey (2 full floors plus roof accommodation with velux windows) built from local stone (Cotswolds, England) which is more expensive than brick and random in terms of size so bricklayers dont like it.

I have a shell price back (i dont need any internals, or windows), and am awaiting another one - but i wondered ballpark how you would price this?

tbh with small scale works its always a loose baseline cost estimate, there are so many variables and the local markets always dictate the costs. Let me qualify it a bit and say we get tenders coming back with huge variations, recently had one where two builders had priced it around 200k and one at 400k - the clients budget was 120k! so it was a comprehensive redesign with the preferred contractor to get to a point the client was getting most of what they wanted for their budget...
yes you always count floor area, gross internal floor area is still gross internal floor area, upper floors should have a slightly lower per m rate than ground floors but with extensions in particular the pricing is always a minefield! things like slappings to existing walls are difficult to estimate as sometimes the cost of temporary propping and needling are much more than the cost of the steel and downtakings.
stonework is always expensive too, especially if done well!

 

[Jez]

I suppose it depends on where you are in the country. You wouldn't get a builder out of bed for that here .

Near Oxford, England. How do you mean you wouldnt get a builder, its a reasonably big job which should keep them going for quite a few weeks i would have thought? But yeah, it is tough getting builders and i am really not sure why as surely this sort of job is a nice one for them.

 

[Jez]

I wanted to extend our back bedroom (single story) by about 1.5metres (the room is 3m x 3m) so what's that, 1.5m x 3m(?) and the quote we got was £30k (London). It's nothing special, at all. Just a basic extension :/

Is extending by just 1.5m even worth the groundworks? Yeah you'd count that as 1.5*3m

 

[Jez]

tbh with small scale works its always a loose baseline cost estimate, there are so many variables and the local markets always dictate the costs. Let me qualify it a bit and say we get tenders coming back with huge variations, recently had one where two builders had priced it around 200k and one at 400k - the clients budget was 120k! so it was a comprehensive redesign with the preferred contractor to get to a point the client was getting most of what they wanted for their budget...
yes you always count floor area, gross internal floor area is still gross internal floor area, upper floors should have a slightly lower per m rate than ground floors but with extensions in particular the pricing is always a minefield! things like slappings to existing walls are difficult to estimate as sometimes the cost of temporary propping and needling are much more than the cost of the steel and downtakings.
stonework is always expensive too, especially if done well!

Yeah, its difficult to know where to price it really. You'd have thought that a reasonably decent sized but basic shell would be an ideal job for a builder, they dont need to mess around once its up doing the intricacies which i would have thought would be up their street. One thing which is off putting (which i can understand) is the use of stone in my area.

Luckily i do have a "usual go to" whose done loads of work for me over the years. I have left him until last though for obvious reasons and have no price yet from him.

I guess i am looking at 78sqm if you include the loft accomodation, was wondering what your general estimate per metre was shell and roof only as opposed to finished, obviously finishing should add quite a premium.

 

[Kol]

Is extending by just 1.5m even worth the groundworks? Yeah you'd count that as 1.5*3m

We've given up on the idea. I think it's just such a small room the extra space in our place (it's Victorian so everywhere is tiny/storage is at a premium) we wanted to make it potentially our main bedroom leading on to the garden. But, yea, you are right, for the hassle to gain 1.5m we've decided against it and shoved a sofa bed in there.