Structural Engineer to review as-built dormer roof + foundations

I need a UK-based structural engineer confirm the structural design for my house project and produce a Building Control–ready pack.

Part of the loft conversion (including a pitched dormer) has already been built and Building Control have said there are things missing from the previous engineer’s calculations because they do not show how the dormer integrates into the roof or how the ridge is supported.

I now need an engineer to review the as-built structure (photos available) and issue revised calculations and drawings that building control can approve.

I need someone who is able to put together the information required by building control. I attach the previous document but this is the reply I got from building control:

I also need some calculations to confirm that the 2 story (1.5 story really...) extension built from 200mm structural insulated panels (SIPs) are suitable at 1m depth in clay soil.



Good morning and thank you for sending through the structural calculations.

Having had a quick look through that information, it appears there maybe some information missing in that document, as there is no reference to the pitched loft dormer section of the roof to the loft conversion and how that integrates with the main roof?

We would normally expect the engineer to produce a drawing that shows all the roof timbers and structural supporting beams for a loft conversion. At present the only drawing section in the calculations document appears to show only the main roof section, with no reference to the additional load that will come from the pitched timber dormer section, that will need to connect into the main roof/ridge timber. The dormer side wall/timbers also need to be supported and generally those would need to be either double or triple timbers each side to support those side cheek walls. We would also query/question the fact that only a single ridge board is shown to the main roof.

Generally, where a dormer roof is formed as part of a loft conversion, we would normally expect to see either a flitch beam or even a steel ridge beam used at that location where there may be additional loading paced on the ridge . This is something we feel the engineer would need to consider and provide calculations & additional drawing details for please as part of their design at this stage.

If there are any other beams required as part of the extension works, then those should also be included within the structural calculations please.

Please discuss this further with your engineer and re-submit any additional information when completed for the loft conversion.