This is fair for a single storey extension and partial loft conversion?

PiggyBankShaker

After a lengthy process, we finally have plans from our architect for our single storey extension and creation of a mezzanine above one of the bedrooms. We are in the process of trying find a builder but everything has gone bonkers at the moment and so far only one has got back to us with a 'pre-estimate' (we've contacted about 8 I think) He has given us the figure of £80,000+VAT for labour and trade materials, which seems like a lot. We had been hoping for something closer to about £65,000 all in but excluding the kitchen. He has said that if his pre-estimate sounds okay, he will come and do a site visit and work up a proper quote. My question is, is this about right for what we want to build? Or is it a tactic of some sort to see if we have the capital? I attach the drawings for the ground floor (and original floorplan) and would welcome any guidance, feedback and advise people have to offer. Thanks.

FaceHead

Lots of 'what's included?' type questions - i.e. is the 80+VAT=96 for everything decorated and finished (kitchen installed you to supply?), does it include the glazing etc.

Putting all that to one side we'd need a lot more detail to assess whether 65 is dreaming or realistic and 96 outrageous or sensible. 

For a project of this scale, I would get a professional estimator to price up the build for you. Yes it's another £100-£200 fee before you even start work, but knowing what is fair will really help you both come to terms with the cost of this, and also to negotiate with builders. 

I have found having a fully disaggregated estimate allowed me to compare quotes with different exclusions, and to make the right choice. 

A further move is to openly say you were hoping to get it for 65k excluding kitchen, and ask what could you change to achieve that. 

I can't see the dimensions properly, but that looks like a big steel across the kitchen/diner. It's taking a lot of load from upstair, meaning it might not be able to simply rest on the existing walls - there might be significantly cheaper ways of doing things, even if it does give you a less desirable layout. 

I don't think the builder is trying to scope out your bank balance - I think they simply don't want to drag themselves round there and make up a proper quote, only for it to be twice what you have in mind. 

Section62

FaceHead said:

I can't see the dimensions properly, but that looks like a big steel across the kitchen/diner. It's taking a lot of load from upstair, meaning it might not be able to simply rest on the existing walls - there might be significantly cheaper ways of doing things, even if it does give you a less desirable layout. 

There's no dimensions or notes relating to that, but roughly scaling it would appear to be approximately 9m long supporting a 9" external wall plus (presumably) some roof load.

I can't help but feel the architect hasn't (yet?) optimised that aspect of the design. :x


I'd also see the side extension (utility room) part to be sub-optimal.  Assuming it means closing off the only external means of access to the rear garden it will complicate the build process (once above footings level) and there is no 'straight' route for carrying anything from the front of the house to the rear.  At minimum it would help if the front and rear doors of that part were aligned so a straight-through route is possible.  (ignore this if there is alternative external access)

In preference though, I'd move the utility area somewhere that leaves external access to the back garden - especially as the drawing appears to say something about demolishing an existing stone wall and rebuilding up to the cavity wall.  Mucking about with stone walls won't be cheap, and if at all possible I'd want to keep well away from them.

PiggyBankShaker

FaceHead said:

For a project of this scale, I would get a professional estimator to price up the build for you. Yes it's another £100-£200 fee before you even start work, but knowing what is fair will really help you both come to terms with the cost of this, and also to negotiate with builders. 

Thanks so much for your post. I didn't know about professional estimators, and I think it is a great idea and we'll definitely do that as in the entire scheme of the build it is a small fraction if cost for peace of mind.

PiggyBankShaker

Section62 said:

FaceHead said:

I can't see the dimensions properly, but that looks like a big steel across the kitchen/diner. It's taking a lot of load from upstair, meaning it might not be able to simply rest on the existing walls - there might be significantly cheaper ways of doing things, even if it does give you a less desirable layout. 

There's no dimensions or notes relating to that, but roughly scaling it would appear to be approximately 9m long supporting a 9" external wall plus (presumably) some roof load.

I can't help but feel the architect hasn't (yet?) optimised that aspect of the design. :x

Thanks for your post. The steel with be 8 metres long. Could you possible elaborate on what you mean when you say the architect hasn't yet optimised that aspect of the design?

Also, there is back access in the form of a gate. It was our choice'idea to go up to the stone wall and incorporate it as the outer wall because we didn't want to be left with a tiny 'dead' strip. I agree that the through flow in the utility/bootroom could be better but I figured that we could change that at the build stage and it wouldn't need to go on teh drawings.

PiggyBankShaker

I should add that we got the figure of £65,000 from square metre price guides for extensions and just worked out what size footprint our build would have... not scientific I know, but the architect dodged every single attempt to get a ballpark estimate off him.

Doozergirl

Section62 said:

FaceHead said:

I can't see the dimensions properly, but that looks like a big steel across the kitchen/diner. It's taking a lot of load from upstair, meaning it might not be able to simply rest on the existing walls - there might be significantly cheaper ways of doing things, even if it does give you a less desirable layout. 

There's no dimensions or notes relating to that, but roughly scaling it would appear to be approximately 9m long supporting a 9" external wall plus (presumably) some roof load.

I can't help but feel the architect hasn't (yet?) optimised that aspect of the design. :x


I'd also see the side extension (utility room) part to be sub-optimal.  Assuming it means closing off the only external means of access to the rear garden it will complicate the build process (once above footings level) and there is no 'straight' route for carrying anything from the front of the house to the rear.  At minimum it would help if the front and rear doors of that part were aligned so a straight-through route is possible.  (ignore this if there is alternative external access)

In preference though, I'd move the utility area somewhere that leaves external access to the back garden - especially as the drawing appears to say something about demolishing an existing stone wall and rebuilding up to the cavity wall.  Mucking about with stone walls won't be cheap, and if at all possible I'd want to keep well away from them.

From a simplicity point of view, there is a new dividing wall being put in the middle of the new dog legged extension, whilst a huge steel is then required to open up the existing space and hold upstairs.  Plus they want to take out the corner and rebuild.  That's a feat of engineering.

Logic dictates that it is easier to build something squarer and more open on the right hand side then knock through into part of the existing kitchen if wanting to take advantage of some of it.  The utility can replace part of the kitchen and be much bigger if you just allow a door into the garage off the main room instead of a VERY expensive new hallway and tiny utility.  

If continuing with this layout, I'd really look at where furniture is going and how the room is laid out.  Design it how you're going to use the whole thing, don't
build it and then shoehorn things in or discover that your seating area is in fact a walkway. 

The design above isn't value engineered to achieve the most space for your buck.   You can value engineer and still achieve what you want.  

Section62

PiggyBankShaker said:

Thanks for your post. The steel with be 8 metres long. Could you possible elaborate on what you mean when you say the architect hasn't yet optimised that aspect of the design?

Is 8m the opening width, or the actual length of the beam?  It isn't entirely clear from the drawing where the bearings are. I think it might be longer that that.

What I meant by optimisation was an ~8m beam is a long one and given the loadings involved it will be on the chunky side. Assuming there's a size of steel which could do the job without an intermediate support, getting a beam of that length into position will be quite a challenge when the builder is limited to manual lifting - and that assumes there is sufficient working space to manoeuvre it into place.

I suspect, but I could be wrong, that once the plan has been looked at in detail by a SE and then a builder, the architect may need to come up with a plan 'b' which offers a better optimisation of space provision vs cost vs buildability.

At the moment you have a 'wow factor' plan.

(or as Doozergirl has added while I've been typing this post, it is all about value engineering)

PiggyBankShaker said:

Also, there is back access in the form of a gate. It was our choice'idea to go up to the stone wall and incorporate it as the outer wall because we didn't want to be left with a tiny 'dead' strip.

How feasible is it for the builders to use that back access for working on the rear of the property?  Is there road access that side, or only a path?

Personally I'd revisit the design to avoid having to work on the stone wall.... my gut feel is it is asking for trouble and a lot of extra expense to make modifications to it.  If @stuart45 sees this thread he might be able to comment more authoritatively than me though.

What is currently on the other side of the wall?

PiggyBankShaker said:

I agree that the through flow in the utility/bootroom could be better but I figured that we could change that at the build stage and it wouldn't need to go on teh drawings.

That's a really bad idea IMV.  You need to aim to have the final plans by the time you go for planning and BC approval.  Some changes are possible during construction, but they should be limited to unforeseen things if at all possible. It is particularly problematic getting a builder to quote on a set of plans if you know you want to change them - if there are any other things like this you plan to change later then you need to deal with them as early as possible.

Moving the doorway may only have limited impact on cost and structural considerations - but someone needs to look at the interaction of that door and the one from the dining area.  Things like that can sometimes have implications for building regulations as well.

Moreover, it would be concerning to me if my architect had effectively designed the door in the wrong place, and that hadn't been picked up before the final version of the drawings.....

PiggyBankShaker said:

I should add that we got the figure of £65,000 from square metre price guides for extensions and just worked out what size footprint our build would have... not scientific I know, but the architect dodged every single attempt to get a ballpark estimate off him.

The problem with that approach is the figures you see quoted are usually on the basis of relatively straightforward builds.

As soon as you depart from the straightforward the costs can quickly add up.

I'd identify (at least) three things on your plans which are not straightforward, and therefore cost increase risks -

*That beam
*Stonework
*Access arrangements

...there could be more.

Again, if the architect doesn't know what budget you are working to, and what his design will cost, alarm bells should be ringing rather loudly by now.

Doozergirl

Worst drawing ever on my phone, but it's
just an easier layout.  Utility sunk into the garage a bit, or it could take the top left area if you're desperate for such a long garage.  

£80,000 plus VAT for what is has been designed, plus some level of loft conversion upstairs is not an unreasonable sum.   

My scribble means less footings,
less engineering, less steel, less work, more usable space and also appears to avoid the gas
main and meter - which is expensive to move and loses your heating and hot water for a significant period of time if you were hoping to still live there during the work.   Also, is that a bifolding kitchen window?!   None of this stuff falls under 'average' square metre type costs.  

Not sure how my scribble fits into the context of the garden, or neighbours, of course.  

 

Doozergirl

Oh, and there's an Air Source Heat Pump.  This is a Victorian house, no? 

My heat pump quote was £12k into a brand new house already set up for a heat pump.  You need to upgrade all the insulation to the house and change all your radiators to bigger ones or install underfloor heating (which needs insulation below).  Did the architect talk about that? 

stuart45

Section62 said:

Personally I'd revisit the design to avoid having to work on the stone wall.... my gut feel is it is asking for trouble and a lot of extra expense to make modifications to it.  If @stuart45 sees this thread he might be able to comment more authoritatively than me though.

I'd say it's doable, but will cost a bit. Not sure of another design, but that's not really my field.