building regs and indemnity insurance

laylaw

dont know if anyone can help. My husband and father in law have drawn up plans for a single storey extenstion to our house that has been approved and fil is currently applying for building regs.

Our concern is if our plans and designs are approved, a builder builds it to the specification, we get a completion certificate and then something goes wrong with the structure/extension afterwards, who can we go to to claim against their insurance? Is the building inspector/council as they signed off the plans? Do we need to involve a structural engineer with indemnity insurance who we can claim against or can we take out our own indemnity insurance if it goes wrong? The builder will just say that he built to the design we gave him.

any help or clarification on this matter would be gratefully received, thanks.

Doozergirl

When you build, it is inspected by Building Control on many occasions. They will check it is being built correctly. Once it's finished and signed off, you can be satisfied that it won't fail based on it's structural integrity. The structural engineer needs to have Professional Indemnity Insurance - if he has calculated wrong (not a lot to go wrong on a single storey, tbf), that will cover you.

Your own home insurance will cover you from that point.

As for the builder, if he is a member of the FMB you can pay for an additional insurance policy as a % of the bill of the work. It's likely to be more than the cost of your annual home insurance. Whether it's worth it?

laylaw

thanks for your advice. trouble is at the moment we havent employed a structural engiineer to do the ridge calculation. It is going to be a vaulted roof with no cross beams. A friend has said he can do the calculations for us but what i dont want to do is rely on him and then if things go wrong but if building control check the technical aspect of the designs and building works ad hoc through the build I am assuming we are covered. Our friend doesnt have prof indemnity insurance.

its really hard to find independent advise or where to start when you know nothing.

thanks

poppysarah

Building control man will want to see the calculation. Getting it done paid won't cost a huge amount compared to rest of work.

timmyt

your contract is with the builder, the Council are there to certify it complies with legislation, not the same thing.

sonastin

Building control aren't their to check the detail of your engineers work. Their remit is to check that you are having work done in the proper manner and the design complies with current legislation. e.g. they will check that the right sort of calculation is being done but not that the sums add up. You could only attempt a claim against the building inspector if the engineer's mistake was so blatant that the inspector was negligent in failing to notice.

You can't expect to be protected by an insurance policy if you're not prepared to pay for the service that you want covering. Professional indemnity insurance doesn't come cheap. If you trust your friends capability, take the risk but if you want peace of mind, pay the few hundred £ to get the design done professionally - a large part of that fee will be paying for the insurance policy.

Richard_Webster

I think you have to draw a distinction between a structural calculation that would be checked by a building inspector and either accepted or rejected and issues of design.

If there are several ways of achieving the same general objective (e.g building an extension to provide extra accommodation) then some may be better than others. They may all be acceptable in terms of building control but e.g. one design may have intrinsic problems with it so that problems may occur later because it is more prone to storm damage or leaks. For instance a flat roof is cheaper initially than a pitched roof but needs to be replaced every 15 yaers or so because it will become prone to leaks.

I am talking in the abstract but can you see that if you design it yourself then if it is the design per se that has the intrinsic potential problem then you have only yourself to blame?

All a structural engineer would do would be to say that if you want to do it a particular way then you have to use this size RSJ or this size beam etc. If he gets that wrong then you could sue him, but this is not very likely because it should not pass building control if it was substandard.

If you have an architect design the whole extension for you then he should point out the advantages and disadvantages of various methods of construction and make you aware of possible issues with each so you can decide. If he doesn't do this and designs something that has intrinsic problems then you may be able to sue him later.

Amphion

Hello,

I am a structural engineer and have worked with many clients who have drawn their own plans for houses and extensions. It’s not really a method I would advocate but it seems to work for a lot of people looking to put their money saving expertise to good use. If this is the avenue you decide to go down then I’ll advise you as best I can. I don’t know what experience of house design your husband and father in law have so for the purpose of this explanation I’ll assume they know very little.

Firstly I would suggest that you do consult an architect, architectural technician or a competent builder at some point for advice as there is a lot more to the Building regulations than just structural adequacy. You need to know about things such as fire regulations, means of escape and heat loss

What you must also remember is that plans drawn by you are the basis of the whole construction and even if the plans are signed off by building control this does not necessarily mean they are correct. There could still be an error with the dimensions that won’t have been picked up and cause problems at the construction stage. Errors in plans can cause expensive delays when construction begins and at the end of the day the builder will build what’s on the plans and happily collect his pay check. So make sure you check everything then check it again
When you make your application A Building Control surveyor job is to ensure that any building work meets the minimum standards set out in the building regulations and that’s it.
Part of this is to check the structural stability,They will want to see how the loads form your extension will travel safely down to the foundations and that the structure is fit for use. When you submit calculations they are checked by a qualified engineer and either passed or rejected. What they aren’t there to do is to absolve you of any responsibility if there is an error with your plans that doesn’t concern them.

For a vaulted roof you will need to provide structural calculations. These needn’t be expensive and you should be able to find a qualified and indemnified structural engineer willing to do these for about £200 + Vat. Shop around as with all products and services prices vary dramatically. Try and find an independent sole trader as they tend to be cheaper than a consultancy.

Best of luck and if you have any questions please feel free to ask, I'd be happy to help.:)


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