Structural Engineering Calculations Costs

[Teebs]

Hi All,

We're in the process of adding a rear extension (single storey) & side double storey extension that requires the services of a Structural Engineer. It total, it's around 4 RSJ's that will be required, a couple of significant size (6m length or so).

We've had a recommended Structural Engineer visit the house (recommended by the builder..) who has quoted £1400+VAT for the building regulation approval calculations & steelwork details for the fabricator (excludes cost of steel).

Based North, does that quote seem reasonable?

Many thanks.

[dxg]

I was literally going to say £1,500 so that seems like a fair price.

I paid £1,000 for some lintel and replacement purlins calcs a couple of months ago...

[dxg]

Are they charging separate for any site visits?

[Teebs]

No, that fee is for everything.

[robbieduncan]

I am in Harrogate and had an extension built last year. The structural engineers were contracted in November 2018. Structural engineers were in Wakefield and charged £250+VAT for

1. Design of pair of beams (B1a/B1b) for knock-through to extension.
2. Design of beam (B2 + Plate) over rear bi-fold doors.
3. Design check on beam bearings/ padstones.
4. Design check on supporting walls/ piers.
5. Design check on existing/ new foundations.
6. Prepare drawing showing all structural information.

This was PDS Design: www.pdsdesign.co.uk

Note they were supplied drawings by the architect: if you don't have architectural drawings may cost more? The structural engineers then supplied their own drawings and pages of calculations to back up their specifications for buildings control

Edit to add: no site visits from structural engineers: they worked from architects drawings only

[Teebs]

robbieduncan said:

I am in Harrogate and had an extension built last year. The structural engineers were contracted in November 2018. Structural engineers were in Wakefield and charged £250+VAT for

1. Design of pair of beams (B1a/B1b) for knock-through to extension.
2. Design of beam (B2 + Plate) over rear bi-fold doors.
3. Design check on beam bearings/ padstones.
4. Design check on supporting walls/ piers.
5. Design check on existing/ new foundations.
6. Prepare drawing showing all structural information.

This was PDS Design: www.pdsdesign.co.uk

Note they were supplied drawings by the architect: if you don't have architectural drawings may cost more? The structural engineers then supplied their own drawings and pages of calculations to back up their specifications for buildings control

Edit to add: no site visits from structural engineers: they worked from architects drawings only

That's great, thanks for the info - I've dropped them a note.

Seems to be a wild variance in prices....!

[shatter]

I've just got a price that includes a site visit in West Yorkshire.

It covered 3 steels being fitted, changes to 2 extensions at either end of the building and looking at calculations for converting a loft space.

This cost was £1200 all in (the guy wasn't VAT registered)

Hope that helps

[Teebs]

shatter said:

I've just got a price that includes a site visit in West Yorkshire.

It covered 3 steels being fitted, changes to 2 extensions at either end of the building and looking at calculations for converting a loft space.

This cost was £1200 all in (the guy wasn't VAT registered)

Hope that helps

It does help, thanks. We've got some more steel than the above so the increased cost is understandable..

[aeropilot]

Teebs said:

Hi All,

We're in the process of adding a rear extension (single storey) & side double storey extension that requires the services of a Structural Engineer. It total, it's around 4 RSJ's that will be required, a couple of significant size (6m length or so).

We've had a recommended Structural Engineer visit the house (recommended by the builder..) who has quoted £1400+VAT for the building regulation approval calculations & steelwork details for the fabricator (excludes cost of steel).

Based North, does that quote seem reasonable?

Many thanks.

I'd say that was a v.good price, but that's more because I'm in the south!

[Teebs]

aeropilot said:

Teebs said:

Hi All,

We're in the process of adding a rear extension (single storey) & side double storey extension that requires the services of a Structural Engineer. It total, it's around 4 RSJ's that will be required, a couple of significant size (6m length or so).

We've had a recommended Structural Engineer visit the house (recommended by the builder..) who has quoted £1400+VAT for the building regulation approval calculations & steelwork details for the fabricator (excludes cost of steel).

Based North, does that quote seem reasonable?

Many thanks.

I'd say that was a v.good price, but that's more because I'm in the south!


I've gone out to 3 other companies for a quote and to see how it stacks up..

[eps]

Once spans are longer than 5m they start to become a little tricky and you have to manage a few other issues which aren't so prevalent on 4m and shorter. 1200 all in, sounds good to me, as long as it is for a decent job. Of course it depends on how much load there is acting on the steels and what is below them - i.e. open space or doors etc..

I would want to see maximum deflections, end point calculations with pier stability and lateral stability of the steels.

[number2]

I had calculations and a report for one RSJ (c. 4.4m) and it came to 5 hours x £125 per hour + VAT = £750, based in the south east.

There was one site visit and he'll pop his head in to make sure there are no surprises when the floor is exposed, and will respond to queries on calculations etc.

Edited by number2 on Tuesday 10th March 11:45

[Teebs]

Thanks all, most useful. I've one quote come back with a much more detailed analysis of what's required for £500 less than the original quote.

It's still over £1,100 for the work, but as mentioned above, it's quite a complex job that is going to involve a good amount of steel.

[JackReacher]

Bumping this thread as I have a related question. Is it normal that calcs are performed based on architect drawings with no site visit? How do they know which way floor joists etc run?

[fat80b]

JackReacher said:

Bumping this thread as I have a related question. Is it normal that calcs are performed based on architect drawings with no site visit? How do they know which way floor joists etc run?

I don't know what is normal, but in our case (8 steels & reconfiguring the back of the house), there was a site visit at the beginning to poke around and dig holes in ceilings etc.
And even then, when we started the build, we had to get them back (more £) as it wasn't all constructed as we thought and bits were redesigned on the fly.

I don't really see how it could have been done without seeing the actual construction. Maybe for a simple extension it could be but for anything existing, I would have thought someone needs to visit.

[aeropilot]

JackReacher said:

Bumping this thread as I have a related question. Is it normal that calcs are performed based on architect drawings with no site visit? How do they know which way floor joists etc run?

Depends.

All new build with enough info on the arch drgs......you could......but I know very few (if any) Struct Eng's that would ever trust a set of Architect drgs.

But domestic dwellings stuff is another world that's a bit alien to my experience of industrial/commercial.

Edited by aeropilot on Sunday 5th July 09:31

[Pheo]

I don’t remember our structural engineer visiting for our plans for extension and loft conversion. I did find that a bit odd at the time.

[Equus]

It does depend on the complexity of the work and the quality of the architectural drawings.

The structural engineers we use mostly don't do a site visit, but then our drawings (and supporting photographs) usually give them them all the information they need (including, in the case of loft conversions, for example, the sizes and spans of all the existing structural roof timbers).

At the other extreme, there is sometimes some stuff, of course, that not only needs a site visit to establish, but you can't really do so until the work starts in earnest as you need invasive survey to establish what's going on with the existing structure.

[anonymous-user]

No visit, removal of structural walls, advising on steels, £3-500 inc VAT.

Recommended by the builder who is an old school friend.

North West.

[Mtrizzle]

Can anyone recommend a structural engineer in the South East (specifically Surrey). I posted the Architects drawings on another thread, and they have since been revised for the flat roof as advised on here.

Not sure a visit would be needed as it's a 'box' being added onto the house, with one steel required.

Any recommendations appreciated.