Structural engineers

[Whyisitsodifficult]

We are about to instruct a structural engineer. Our architects have said they will get 3 quotes from ones they’ve used before. Can anyone give me a rough idea of what I can expect the quotes to be? It’s for a single storey extension with some interior remodelling if that makes any difference to the price?

Depends on whether they are: 1 man bands or a company; extent of service offered (drawings, site visits etc); location; how busy they are... It could vary from £250 to £1000.

The main thing I would advise is to go for someone who actually visits the house rather than just works off the architects drawings.

Blimey that’s a price variation! Would they be able to give a quote without visiting the house?

They'd normally quote off the drawings yes. The price difference is because the hourly rate people use can be quite different (a one man band has lower overheads for instance). And also whether they are particularly interested in doing that sort of work. Where I work it generally isn't worth our while doing simple domestic stuff as we simply can't compete, and we also want to make sure we do it properly by doing a site inspection etc, whereas some people seem willing to take the risk and do it just from drawings.

Hmm thanks for that, it’ll be interesting to see what they come back with!

Ours was about 2k but it really depends. If it's a basic calculate a beam SE then you would just pay a couple of hundred per beam. But if the architect wants to work with the SE to decide the best value design that would cost more eg our architect went back and forth on quite a few details to get a good compromise and the se designed the roof with massive timber rather then steel because of cost and weight.
Anyway ours was moving walls and two side knock through downstairs plus rebuilding most of the roof.
Also that included a few inspections during the build which turned out to be essential as there were unforeseen missing foundations, walls built off floor boards supporting the chimney that was being knocked down, and some interesting roof designs from the builder.
Building control were not really looking at anything much so it was good to have the check.

I think the architect want to work with the engineer. They have suggested a timber frame but the timber frame companies have said it’s not suitable for them as the design has lots of glass. I can see this heading into the thousands I think!

Oh right, i was assuming a fairly standard masonry extension. I suspect what you are talking about would be more. But still, maybe not that much more. I'd be concerned that the timber frame companies don't want to do it though - that implies it's going to be a tricky one...

Yes I agree, I think sometimes architects don’t really think their plans through! I wonder if there is such a thing as a hybrid architect/structural engineer! Would probably be a lot cheaper!

Make sure the engineer has experience of timber frame - otherwise they can err on the safe side and over spec elements - adding to cost.
Engineer costs round here wouldn't be lower than £1k for an extension but that would be certifying the lot - ground conditions, foundations, superstructure and roof.
I suspect a £250 quote would be for an isolated element of design only (eg a single beam).
A decent engineer can save you money by designing effectively. a lazy one can cost you money by charging less but providing a solution which is expensive to build.

How do you know if he/she is a decent engineer though? With a builder you can and go and see their work and speak to people they’ve done jobs for. Our architect has said he’ll get quotes from engineers they’ve used before so I guess I’ve just got to go with that haven’t I? Thanks for the tips though much appreciated.

We’ve just appointed our SE for a rear extension and loft conversion. Our architect requested 3 quotes, and 2 responded, both within a similar level. I then spoke to the architect about what I saw as differing specs on the quote to clarify what would be done and what else might be needed and then went with our gut following that. Both quotes were around £2100 inc VAT.

Oh and our architect had worked with all the companies which was a big thing for us - he would have to work with who we appointed as well and we trusted his recommendations.

We paid £420 5 years ago, midlands

Wow £2100! What do you actually get for that? £420 sounds like a nicer figure! I guess it makes sense to go with one that the architect has used before. I think we will end up paying about 6k before a brick has even been laid!

Yes we reckon we spent about 10k on stuff that wasn't actually building or of under 100k of work
But all worth it

We all have spent £10k on planning and drawings but they are so important to get the end result, we felt it wasn’t something that could be skimped on. I’ve added a screenshot of the specs from one of our quotes.

*We’ll not We all - I wish there were more of us chipping into this build! 😂