Structural engineer report

[Allaboutyou222]

We need a small first floor extension. We have paid for plans and are looking to get a builder around for advice.

It’s proving difficult. One has asked for the plans and an engineer report. I don’t fancy shelling out for that on top of plans without any idea of how much the extension will cost! It might be unaffordable.

Is it normal for builders to ask for this without even coming out to look at what you want doing!? Or even have a conversation with you?

I'd trust a builder wanting a structural engineer's report more than one who didn't tbh. Presumably he wants to know whether the ground floor he'd be building on top of is capable of supporting a first floor extension? Clarify what the structural report is for and you can then get an idea of costs from a structural engineer.

We've used one twice. First time was to get to calculations for steels when we were removing part of the original external wall of the house and the calculations were necessary for building control. Cost about £400. The second time was to establish whether an internal wall was structural and he spent over an hour investigating and told us it wasn't. Didn't charge us as old houses really interest him and we didn't need a report from him.

how do you expect a builder to quote for a job without knowing what the engineering requirements will be?

I don’t expect a quote at this point. I just wanted a builder to even give me an idea of cost! Just so I know it’s worth proceeding. I could end up a few grand down and find I can’t afford the cost of the extension anyway.

Last time we had work..builder looked at job first. Gave us a very rough idea of cost. We then got a formal quote once he’d seen the plans.

I know we will need a report eventually but I don’t know if I can even afford an extension as no idea how much it will cost! And no one will tell me.

In a nutshell yeah, this is best practice. And make sure you understand it properly.

So I have to pay for 2 reports without an inkling if”of even basic cost? I literally have no idea how much an extension will be and I don’t want to spend loads on reports that will be useless if I can’t proceed.

Seems unworkable to me.

When you say a small first floor extension, are you wanting to build on top of a single storey structure already in existence?
If so,
Does the room have foundations? how deep are they?
If you want a ball park figure, perhaps ask someone who has recently finished a similar project.

Is the current structure flat roof or pitched roof? What sort of roof are you planning for the extension?
Spec the job.
Size
Windows , size. Plastic or wood.
Door, locks and hardware?
Roof, slate or tile, reuse materials? Match to main house?
Render or Brick? Match with current bricks or contrast? Are they still available?

Electrics, how many sockets how many light fittings, wall or ceiling fittings? Hardware,
Interior finish, doors hardware skirting architrave.
Decor and fittings? 3 coats Trade white or farrow and ball colour.
Where are your sewers and drains.
Access.
Making good outside? Steps, landscaping ?
Think about your requirements they all affect the price.

I can so see why they want a report! For example if you end up needing loads of structural steelwork that’s £££ and a builder won’t really be able to tell you that

You don't need a structural report, you need to find a Structural Engineer, send them over your architects drawings and ask for a quote for the Calculations that may be needed based on the drawings. They will let you know how much and if a site visit is required to look at the foundations etc.

Builders are overrun with work so can be picky. Yes they can give you a guesstimate but the reality is that it will nearly always work out a lot more. Our guesstimate was £40-50k and out turned at £80K. That was 5 years ago and the true quote came from the full plans and crucially the building control drawings.

To put in context, our neighbour is wanting to build exactly the same extension we built, and it getting quotes if £150k plus. That's what I call inflation

But yes, no builder can quote without the plans. Be wary if the builders that want to work without full plans and detailed specs

Yeah this is normal. We are currently having an extension built (single story) and the builders needed plans and a structural report. it cost us £2500 before we could get a price. I wouldn't trust a builder who didn't want that information and I would not trust a quote based on a guesstimate. If you want some context of prices, we are having conservatory taken down, walls knocked down to make it open plan, exenstion on the back, bifold doors and velux windows etc. Ours is 55K with kitchen fitting, decorating on top of that. We are up north and had to book the builder a year in advance.

Yes I do have experience of getting work done. We weren’t asked for structural plans before the builder would even look at it.

We had a quote for a loft extension of £65 k from a well established builder. He didn’t ask for the structural report until he’d looked at the job.

Btw I’m not looking for a quote based on an estimate. I’m looking to have a conversation really!

@Allaboutyou222
You have not been clear what a first floor extension is and why the builder might have wanted a structural engineer to look at it. The clear implication would be that it’s not straightforward. Loft conversions use space already built. A first floor extension is likely going on top of an existing part of your house. Therefore it’s important to know about that structure and it’s foundations. If it’s not suitable for building on, then it might have to be pulled down and deeper foundations dug etc. There might be pretty major decisions to make before you can “guess” at a price.

A big standard addition used to be around £2,000 per m2. You could be looking at £3,000 m3. If you require new foundations and alterations/demolition it will be more. So that gives you a start but no one can be accurate until they know what the structural issues might be. It’s just an additional cost when building at first floor level!

Builders don't have time 'to have a conversation'. And asking for ballpark figure is not helpful - as stated above it could range from 2-3k/Sq meter to heck of a lot more if foundations needed reinforcement.

Builders don’t have time to have a conversation? So they can’t come and look? Rubbish.

I have had work done in the past. Builders came to look. Had a general chat about possible options and I then obtained plans which they used for a formal quote. I have 3 lots of work done on my house and was never previously asked for a structural engineer report at the very start.

OP: I want builders to quote on work without them knowing what needs doing.
MN: That's not likely to happen.
OP: I want it to. You're all wrong.

@Allaboutyou222
Just get your plans drawn up and talk to your architect. I’ve never started with a builder first. They should quote on plans. Plus if your project isn’t straightforward then they will need plans.

from what I gather (friends & next door neighbour) you will find yourself having a long wait -let alone getting one to visit on spec. There is this a thing called Brexit where a lot plumber & jobbing builders left & that's to start with! let alone importing timber, bricks & other building material.
My friend has been waiting for a year to get her extension done - ditto neighbour. I have heard of builders that are so busy they can't finish their own build!
So don't assume your prior experience is a reflection of what you can expect now.