Extension costs

[Mr C]

I tried to find an existing topic but it seems they were almost a year old.

Could anyone give any idea on what i should expect to be paying for my extension to be built, i'm getting quotes at the moment, its taking a long time and the first one seemed much higher than i anticipated and would like to know if i have miscalculated.

I have already had an architect draw up plans and notes and building regulations approval, details are as follows:

The extension is intended for a new kitchen
Destruction of a small outbuilding will be necessary prior to construction
Approx 3 x 5 meters in size, single story
2 x 1 roof lantern

Possibly an inclusion of a folding internal door approx 2m in width. Remodelling of old kitchen into utility room / toilet, will need to move the boiler too. The location is in the Midlands

From what i have seen and tried to estimate myself it should be no more than £30,000 in total (hopefully with the kitchen installed too)

My first quote was around £34,000 + VAT (£40,000+) that is without any kitchen, tiling or flooring. Is it me or is the builder's quote too high?

 

[Martynt74]

My brother in law had a similar sized extension done and I think he said his shell was around 20k then obviously extra for the kitchen so I’d have thought your 30k seemed reasonable.

Have the builders given a detailed breakdown?

 

[the_r_sole]

It's not hugely out imo, 15m2 at say 1750 per m2 is 26k then say couple of grand for roof lantern, three ish for the bi-fold puts you at 31k then another three for demolition, disposal of waste, slapping to existing building etc...
It's not cheap but it's not hugely expensive either - builders generally don't consider vat when pricing as it's just something they pass on. Tbh 34k tender return is pretty good going for a 30k budget, negotiate with the builder and see where savings could be made

 

[Mr C]

I did have a more thorough breakdown which seemed reasonable for everything listed as provisional and then the total was the 34k +VAT.

The prices quoted by the builder are less than half of what the previous poster just estimated.

Fitting of and cost of bifold doors were quoted at £900
Fitting and cost of roof lantern PVC external door and windows were £2900

I checked costs of roof lanterns prior (in fact the builder in this quote used a cheaper PVC lantern as opposed to the aluminium one i costed at £1150) and i have it easily costed and delivered, considering they take an hour or 2 to fit i wouldn't expect it to be anymore than £1300 fitted even.

The above plus electrical plumbing and heating came to a total of: £8400.

Taking that off the total cost leaves me with £26,300 to account for everything else not provisionally listed, i couldn't imagine paying £1750 per metre squared (before VAT) for what is a simple rectangle shape outside of the south east and London.

I have had the demolition cost by a different builder in the past for about £1000. The problem i have is i am happy with his provisional costs for all the other work its just the total amount with VAT is essentially 25% over my estimate of £30k.

 

[the_r_sole]

I work all over the UK at the moment and in my experience there's not many jobs coming back under 1750 per m2 - if you've got a detailed quote back then you shouldn't have anything unaccounted for, obviously my post was based on assumptions rather than specific details that you didn't give in the op.
Get three quotes and compare them. The cost you have isn't outside of the realms of possibilities... You just wanted someone to say it's too expensive didn't you?

 

[Mr C]

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_r_sole]

Well, my first advice was based on the limited information in your op, a finger in the air saying it's not unreasonable...
Whilst a roof lantern may cost 1200 quid for the actual lantern, there's a roof upstand to be formed, roof trusses to be trimmed, insulation and plastering to the inside opening, flashing down on to the roof etc it's not as simple as saying it takes a couple of hours to install.

Most small builders don't like tendering jobs, it's a necessary evil, but can be very time consuming. Some I know won't tender directly to domestic clients, they will only tender if there are proper tender documents with a form of contract proposed and a professional involved in assessing the tender returns and running the job on site. Tendering a job directly sends out two subtle messages, that you might not want to pay for things to be done properly or that you like to micromanage the process, neither of which is particularly attractive.

If you have approached 10 contractors and only had a single return there is something wrong with either what you are asking them to price or how you are asking them to do it.

 

[Jez]

Most small builders don't like tendering jobs, it's a necessary evil, but can be very time consuming. Some I know won't tender directly to domestic clients, they will only tender if there are proper tender documents with a form of contract proposed and a professional involved in assessing the tender returns and running the job on site. Tendering a job directly sends out two subtle messages, that you might not want to pay for things to be done properly or that you like to micromanage the process, neither of which is particularly attractive.

What do you mean by tending directly to domestic clients as such mate? I am going through the final stages of planning and getting some quotes for a 3 storey extension and other than getting them out to look, giving them drawings, and asking them for a price, what else can you do?

 

[the_r_sole]

What do you mean by tending directly to domestic clients as such mate? I am going through the final stages of planning and getting some quotes for a 3 storey extension and other than getting them out to look, giving them drawings, and asking them for a price, what else can you do?

Well we usually tender jobs on behalf of domestic clients, it means that the contractors can raise technical queries with us to help them price the job properly (or they can suggest alternatives) it also means the client is serious about getting the job done if they are following a correct process, but that again comes back to the quality of information they are being asked to tender - I would never advise anyone to tender a project based on planning drawings, it really leaves the price open to all sorts of variation, the English approval system has created the cowboy builder epidemic, that's why good contractors have long lead in times and pick and choose the jobs they want.

 

[Jez]

Ahh i see what you mean, as an intermediary project management/architects office? (I guess thats what you run).

You can understand why a lot of domestic customers may not wish to go down that route, it does add significant cost often unnecessarily for a domestic project.

 

[psd99]

Where in the country are you based?

You're looking at 15 meters squared there, as a rough guide charges can range anywhere between £1,000 per square metre up to £2,000 in my experience.

This would purely be for:

- Excavations + concrete
- Wall finish
- Roof finish
- Electronics/plumbing first/2nd fix
- Plastering/skimming.

for the above I would say you should be looking at between 15k to 22k only. Anything more and I wonder question why it is so expensive.

You also have to bear in mind that items/work like the following will incur more charges:

- Sky windows
- bifolding doors
- Patio doors that are big in size.
- Tiling
- Kitchen

There are all sorts of ways builders will trap you to make more money, at the end of the day it is a business for them.

Go for someone that has been recommended to you and that you feel comfortable with.

 

[the_r_sole]

Ahh i see what you mean, as an intermediary project management/architects office? (I guess thats what you run).

You can understand why a lot of domestic customers may not wish to go down that route, it does add significant cost often unnecessarily for a domestic project.

Yeah, people regularly think it's an unnecessary expense but properly tendering a job, negotiation with a contractor and running a contract really pay for themselves over the course of a job and can save the "final bill" hassle or the inevitable client/builder fall out!

Domestic projects, if anything, can be more stressful and more problematic than bigger projects as the client really has an emotional attachment to things, usually living on site and is using their own money to pay for stuff - it can be absolutely fine with a good contractor and a good client, but a solid contract is absolutely crucial to everything. If a builder says they want upfront payments or they don't want to use a formal, standard contract then do not use them, a contract protects both parties and sets out payment terms, retentions etc.

 

[Jez]

I see both sides and definitely see a management agent such as yours as a preferable route if all things were equal

The problem lies in the additional expense this introduces, significantly so, compared with an informal arrangement with a builder and plans produced yourself (which is the route i have always taken). Of course really, to go it "alone" like this, protecting yourself in terms of payment terms and how to resolve unforeseen situations should come as 2nd nature. I would never advise someone to self manage a project unless they are absolutely confident in handling fallout and of course only ever paying in arrears to a builder who is known to them. Some of the horror stories you hear of - those people should never have even attempted to try and self manage with the decisions they have often made to find themselves in those predicaments.

Of course this introduces problems with threads like this, you'll always get two tranches of pricing which are never compatible and are not like for like in terms of service

 

[the_r_sole]

yeah, informal arrangements are great until they go wrong and then there's no easy way to resolve the issues... We regularly have clients who don't want to use us to tender or administer contracts then come back at the end asking us to resolve a dispute with the builder!

 

[Mr C]

Where in the country are you based?
Go for someone that has been recommended to you and that you feel comfortable with.

I am based in the Midlands. I would use someone recommended but myself and almost everyone i work with are relatively new to the surrounding areas, so have no previous contact with local builders. Our neighbour had a suggested builder that we used for our side passageways to be renovated. He was a nice guy and they continued to use him for their extension, he has taken over a year to complete their project (which is considerably larger than mine) with quite a few quality issues, however much that was by the neighbours constantly changing their mind mid build, the lack of planning and architectural drawings (considering they used "his guy" for the drawings to submit to local council anyway) or his quality i don't know but i am hesitant to use him for this project.

I asked my architect to provide me a list of recommended builders of which he did. I contacted 4 from that list and 2 responded, 1 which gave the above quote and the other i am struggling to get one from, i get the impression that they aren't really interested in the tender and are mostly just being polite. To clarify i found the remaining builders advertised online or in local directories, of which i had 1 response and 0 quotes.

If you have approached 10 contractors and only had a single return there is something wrong with either what you are asking them to price or how you are asking them to do it.

I am asking nothing of the builders, simply i am handing them 4 sheets of A3 building regulation approved architectural drawings of existing and proposed extension. 5 pages of construction notes clearly stating the materials to be used. Covering; drainage, foundations, DPC, cavity walls, existing walls, trimmers, stud partitions, flat roof, windows, doors, roof glazing, area of glazing compliance, ventilation and heating. It is also accompanied by the structural calculations from a third party structural engineer for the supports of the roof lantern.

I am not implying any kind of time scale or start time. I am simply showing them the area and giving them the documents. I am not even telling them what i'm expecting a price to be, i make it clear that if they have any suggestions or alternatives i am willing to listen. I just want quotes so i can make a decision. Personally i don't see how this could be seen as micromanaging anything and since i have gone through the effort to acquire a comprehensive set of designs processed and approved by building regulations it would show that i am serious about the job.

Edit: I kept the OP quite brief as i wasn't expecting to go into such detail for what i was expecting to be a ballpark discussion and figure, i felt listing the dimensions provided and extra cost items would have been enough for a slight discussion on the topic, i apologise in advance if it seems that my consecutive posts seem defensive as i am simply trying to gauge whether i should continue to acquire quotes or split the project up into something more manageable.

 

[a1ex2001]

Odd can't say I've ever even considered tending a job through a third party just another step in the chain taking 10% it doesn't seem to have limited my options in a big city at all!

Back to the OP every job we've had done has cost more than my estimates and more than the architects estimates. Decent builders cost good money and aren't short of work we could probably have saved 5k on our last job by using a different builder but it's not worth the risk. If you want close to a real price get a quantity surveyor involved but again this is more money that won't go towards your build! VAT is a real killer on a decent sized job try and find a builder who will let you pay his lads direct they are almostcalways self employed and not VAT registered!

How are you contacting these builders? Email is basically a waste of time good builders are busy and rarely respond phone them up!

 

[MassiveJim]

Edit: I kept the OP quite brief as i wasn't expecting to go into such detail for what i was expecting to be a ballpark discussion and figure, i felt listing the dimensions provided and extra cost items would have been enough for a slight discussion on the topic, i apologise in advance if it seems that my consecutive posts seem defensive as i am simply trying to gauge whether i should continue to acquire quotes or split the project up into something more manageable.

Ha welcome to OCUK.

If forums are representative of people in business today, no wonder nothing ever gets done nowadays.

 

[the_r_sole]

Edit: I kept the OP quite brief as i wasn't expecting to go into such detail for what i was expecting to be a ballpark discussion and figure, i felt listing the dimensions provided and extra cost items would have been enough for a slight discussion on the topic, i apologise in advance if it seems that my consecutive posts seem defensive as i am simply trying to gauge whether i should continue to acquire quotes or split the project up into something more manageable.

The thing is, based on the original post - the price is in the ball park, or at least not obscene or out of the realms of possibilities - then you immediately counter that opinion with very specific items on your quote, if you wanted a general discussion, why post the minute details.
All you wanted to hear was people telling you it was way over and your estimate was spot on, and when you've not heard that got very defensive very quickly

 

[Mr C]

The thing is, based on the original post - the price is in the ball park, or at least not obscene or out of the realms of possibilities - then you immediately counter that opinion with very specific items on your quote, if you wanted a general discussion, why post the minute details.
All you wanted to hear was people telling you it was way over and your estimate was spot on, and when you've not heard that got very defensive very quickly

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.

for the above I would say you should be looking at between 15k to 22k only. Anything more and I wonder question why it is so expensive.

You also have to bear in mind that items/work like the following will incur more charges:

- Sky windows
- bifolding doors
- Patio doors that are big in size.
- Tiling
- Kitchen

My brother in law had a similar sized extension done and I think he said his shell was around 20k then obviously extra for the kitchen so I’d have thought your 30k seemed reasonable.

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.

How are you contacting these builders? Email is basically a waste of time good builders are busy and rarely respond phone them up!

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.

 

[the_r_sole]

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.