Are these extension "plans" enough to get some rough estimates?

[smp50]

Will these "plans" (below) give a builder enough of an idea about the feasibility of my extension idea and talk through it with me, and give a rough estimate (say +/- £5000), given that my house is of a very common type for the area and similar extensions are not unheard of around here? I'm reluctant to pay thousands for proper plans at this early stage, and need the confidence from a builder being willing to do it.

 

[freddiemercurystwin]

Maybe, but until a builder sees a commitment from you to show that you are serious then why would he bother to invest any serious time doing some number crunching? If he's a good builder he won't need to bother expending time on a whim when he can spend the time putting together serious quotes.

 

[smp50]

Maybe, but until a builder sees a commitment from you to show that you are serious then why would he bother to invest any serious time doing some number crunching? If he's a good builder he won't need to bother expending time on a whim when he can spend the time putting together serious quotes.

So how does it normally work, will a builder not be willing to consider the job until I've gambled £3000 (estimate from another thread) on plans, got PP, etc.? If that is the case, who is it that actually comes to the site, looks around, eyeballs the existing structure and ground, and tells me whether it's a good idea of if the whole thing is ridiculous? Or do I have to get the plans done "blind" and hope they're realistic?

If that's not the builder's job then who do I need to speak to about it? For previous smaller jobs I've had done, contractors have been falling over themselves to come round and chat with me about the idea even without seeing sketches, but admittedly they were lower-cost things (up to a few thousand).

 

[noseall]

How rough are you prepared to accept? £5k out? £10k out? £20k?

 

[smp50]

How rough are you prepared to accept? £5k out? £10k out? £20k?

I would expect, based on this house being very "normal" and this kind of extension being quite a common job, a +/-5k estimate to be quite reasonable in the first instance? But I really don't know, I'm just trying to start somewhere at all, and don't know who the first person is I need to talk to.

 

[freddiemercurystwin]

Highly unlikely you'd get planning permission for that anyway, probably have to set the front a metre back or thereabouts and how would the roof work?

 

[smp50]

Highly unlikely you'd get planning permission for that anyway, probably have to set the front a metre back or thereabouts and how would the roof work?

Oh really? There's one around the corner that's been taken out flat along the original front elevation, so maybe it's possible? I could set the front back a bit but then, indeed, the roof becomes a bit tricky. Come to think of it, the little L-shape I put on those plans makes the roof awkward as well, right?

 

[^woody^]

You won't pay a few pounds for a proper opinion or a few hundred pounds for a detailed design from someone who knows about planning, but will commit to a vague estimate from someone who won't even know if the thing is viable, and which could be thousands of pounds out?

What this mindset fails to understand is that it is the designer who dictates how much the scheme costs, and how much builders quote. Crap design and crap plans mean that your builder quotes more and charges more in extras. It's never a cost saving scrimping or cutting out the designer.

 

[smp50]

You won't pay a few pounds for a proper opinion or a few hundred pounds for a detailed design from someone who knows about planning

Can you expand on that bit - who are you talking about? What kind of person? I would happily pay someone a reasonable amount for a proper "consultation" about it, if only I knew who to ask! This whole thing is a mystery to me currently.

but will commit to a vague estimate from someone...

I wouldn't be committing to anything, it would just be the first step in working the thing out.

... who won't even know if the thing is viable, and which could be thousands of pounds out?

So who does know if it's viable, if not a builder?

What this mindset fails to understand is that it is the designer who dictates how much the scheme costs, and how much builders quote. Crap design and crap plans mean that your builder quotes more and charges more in extras. It's never a cost saving scrimping or cutting out the designer.

I'm not talking about cutting anyone out, I don't even know who's supposed to be involved in the first place


I'm not trying to wind you guys up, I really don't understand how to get started. This "designer" person, is that someone who will come out to my house and stand there with me, looking at it and talking about it, and know for sure whether something is possible based on what he sees around him, etc.?

 

[^woody^]

The designer is the person who is experienced enough to design it to your needs, planning constraints, and building regulation requirements. And do all this cost effectively. This might be an Architect, an Architectural Technician, building surveyor, structural engineer, or anyone who is experienced in the design of buildings.

He will also know if the Party Wall Act applies, if build-over agreements are needed and if engineers need to be involved. He will also know how to design to avoid any of these if possible.

He will know whether to use the council inspector or a private one, and he will know about all potential fees involved, not just the build cost.

This is not the builder who wants as much money out of the job as possible, or who does not want the job or who wants to do it his way.

Your first step should be to get a proper assessment of what is possible based on the site constraints and your budget. It's no good getting an estimate or a even a fixed quote on something that can't even be built.

Bare in mind that someone who can draw plans is not the person you need. It's more than that.

 

[tony1851]

@op, if you don't know or can't choose who to start with, why not look up and read your council's policy guidelines for domestic extensions (on the council's Planning site).

From that, you should be able to see if they require a set-back at the front, or if the side wall of the extension needs setting in - say - 1m from the boundary, for example. At least you should then get a rough idea of what's possible in Planning terms.

(Don't be guided by the extension near you with a flush front - that may be an older one and will not set any precedent; and as mentioned by others, there may be other constraints to consider, but checking policy should give you a starting point).