Who's responsible for structural engineer calculations

Hi Another way to look at it also is how did it get through planning and be passed off? so I would have asked the BCO (Building Control Officer) as it is a failure on there side.

Typically the Architect will produce the planning and building reg drawings! some Architectural practices have their own engineers, others do not? If i'm honest its difficult to say who should have done what, without being party to the initial brief that you had with each individual. however in my professional opinion. The builder from the outset knows he requires this detail prior to installing any Steel RSJ's, as without this detail he will not have the design detail to show to building control for the approval. Any professional contractor should or will ask you for this information prior to works commencing. Structural calculations are not required at planning stage, these only come into effect once either a building notice or full plans application has been submitted into the local authority or independent inspectors. It sounds to me like the build was built under a building notice, this is were the structure is built and inspected as the works proceed, as typically under a full plans application the build design is reviewed by building control prior to works commencing. Do you know if the structure/steels once inserted and placed into position was inspected by building control?. Would you have photo's of these works once they where inserted? (ideally showing connections with padtstones or posts etc) Lastly do you or your contractor have proof of what size beam/beams were/have been installed?? If so you could still discuss this issue with a structural engineer and advise him what has been installed, and then he can see if he can work his calculations to reflect what beams have been installed? Your worse case scenario, unfortunately will be, that your contractor has not installed a large enough beam or just installed a beam on to padstone's, when your build required a goal post or box frame (which is very typical in lots of cases). If this is the case, then you will have no choice but to rectify this problem and insert the correct steel works. hope this is clear? and hope your able to resolve this issue without to many problems.

if you had an architect he would instruct a structural engineer to do them,if not then your builder or yourself.your architect should have known these would be required.

1st. Homeowner is responsible. 2nd. Builder cant fit whatever he wants the way he wants. As builder is just a builder. They mostly dont have higher education and not too good with physics or mathematics or geometry, so only can rely on experience but usually don't understand the process. Like what is span what is spotted load and etc. Don't take it personal guys im builder myself and i dont fully understand how those processes work. 3d. BCO supposed to check SE calculations, the way how beam was installed, need to check if structure below the ground is strong enough to hold the load. Maybe steel pillar needed or anything else. He needs to check all this before beam is boarded

Hi there. If the plans have changed from when architect done the drawings and building control have asked for calculations then it’s the home owners responsibility. If the plans are the same then your architect should have done the calculations. We used an architect tgat designed the house so no structual drawings were needed. Unfortunately my wife changed things so we needed a structual engineer to visit and with liaison with building control it was quite easy to take up floor. Dig a 1m X1m pad and fill with concrete. The steels were then made and fitted by steel company. Extra costs with me doing the work was 3k to lose 1 wall. Some architects try to do drawings without consulting structual engineer and in the notes will try to leave walls in where possible and use catnic lintels and name them with a code. Plans change though so once changed it’s homeowners responsibility. If plans haven’t changed. Then your architect should have the necessary calculations for the lintels used. They are just standard and with the codes you can get them online. It’s all about liability if something fails. And yes all try to pass the buck. And most things are built overkill because of this. If the drawings show a post then calculations for the size of post and steels should have been done before build started by architect. Otherwise how can they design something that may not be structurally sound. We could all do something like that!