Extension virgin - does an engineer have to visit your house to work out steels etc?!

[FourFlapjacksPlease]

About to start a big extension (double height at back and side as well as loft) and have contacted an engineer to calculate steels etc. Have had a quote back but it states it doesn't include site visits and that these are charged separately.

I had assumed they came to the house first before working it all out but do they just work from plans? I am baffled. Wouldn't they need to see the current structure of the loft etc?

Can anyone enlighten me?

Our architect liased directly with them and I assume went through the plans, but no site visit from the engineer was needed.

Should say ours was only knocking down a wall. It sounds like your project will be much more complicated, and I'm sure I read somewhere about architects not being liable if steels are wrong

We are about to embark on our extension project and the engineer never visited. He liaised with the architect (who of course did visit) so I assume he just needed the drawings.

ah ok, thank you! I can't get my head round it at all. I fear I am in for a very long and confusing 6 months!

Is this an engineer you've approached directly or through your architect (assuming you have one)?

I would expect to have to visit the property for a project of the size you are talking about, unless I'd worked with and trusted the architect. Generally it can be done off plans but there can be things that aren't necessarily on drawings (e.g. how close trees are which might affect what depth your foundations need to be). And roofs are especially complicated so I would be very reticent about making alteratiobs there without seeing it for myself.

By site visits being extra they may mean checking things during the job, e.g. if you want to change something halfway through or the builder has a cunning plan to do it cheaper, and they were allowing for an initial inspection for the design. I'd check if that's the case. And get other quotes to see what other people think is necessary (and don't automatically go for the cheapest one).

Brilliant, thank you for the advice. The engineer has been recommended by our builder (who I trust completely, he has worked on loads of friends places and has an excellent reputation) and we have an equally brilliant architect who is a friend. Don't think the engineer has worked with the architect before though.

I will call a couple of other places tomorrow I think and ask them to quote too. The place who have quoted already would charge just under £1000 + vat. Does that sound about right to you? Told you I was clueless!

as 'hill says, it is possible to do it off plans, but very much better to have a site visit.

When it doesn't fit, all the people involved will blame each other, claiming inaccurate measuring, unapproved changes, normal tolerances, insufficient allowance made for pre-existing defects, etc.

"But surely you realised...."
"How could I have known..."
"You should have asked..."
"You should have told me..."

Meanwhile they pore over the drawings trying to show it was somebody else's fault

None of which helps you.

Thanks PigletJohn - will push for a site visit in that case! Binge watched grand designs on catch up last night and now feel sure we will go bankrupt and end up in a caravan in the garden for 18 months!!!

It really depends how much structural alteration you're doing. If it's just the odd knock through but nothing too big that will change the stability of the building then it might not be too complicated.

As a rough guide I'd be looking at between 1% and 2% of the build cost for your engineers fee. It will also depend a bit on whether it is a one man band or a company.

Thanks. It's a 200k build and requires 7 steels i think so sounds like a grand is more than reasonable!

We knocked through a tricky supporting internal wall when renovating - engineer visited for that one. A few years later we extended and knocked through an exterior wall. No visit for that one, possibly as it was more straightforward.

We had a large, complex extension which required five steels. The engineer made a site visit - given that most of the back of the house needed taking out, I found this very reassuring!

We're in the process of having a small extension and knocking through some internal walls. Had a site visit and report from a structural engineer but he mainly studied the internal walls which need removing. Perhaps if yours is just an extension it can be calculated off site as not a danger to the stability of the current building?

That price is very good (and probably explains why we don't try and do domestic job - there's no money in it!)

A bit late but we paid double that to do the structural design for our extension, he came out twice before hand plus 3 visits during construction and it was all necessary.
The first construction visit found the existing foundations wouldn't support the new steelwork, the second found the builder didn't build the walls properly, and the third was too design support for the walls left behind after the chimney was demolished and left nothing holding the rest of the wall beside and in turn the roof up! So all necessary.
The engineer originally said site visits were extra but the architect said that's not good for us as it was time for travelling plus on site about 70 peer hour. So we got three visits included in the price.
Good luck!