Age and type of house
The barn conversion still uses the original timber trusses and they were only seen from the floor of one bedroom. What farm loading were those trusses not reassessed for?
The trusses were not reassessed for the loads they carried as a farm building, nor for the different loads a house now hangs on them. Stored crops, equipment and an open agricultural roof are not the same duty as ceilings, insulation and rooms. The surveyor saw the original timber trusses only from the floor of one bedroom. That is a limited view. It is not a structural calculation. Approved Document A is structure guidance. This visit has not applied it as a check of these trusses.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Barn conversions often keep the frames that once spanned a working farm roof. Those members may have been notched, repaired or asked to carry ceilings they were not built with. From one bedroom floor the surveyor might see a few feet of timber, a joint and the underside of the slope. They cannot see the bearings in the walls, the full span, or timber buried above a new ceiling. Describing what was in view is the finding. Capacity was not recalculated.
If the farm frame is being relied on as the house roof, ask a structural engineer whether these trusses need a proper reassessment, and say how little was seen. Your solicitor should have the conversion drawings and the building-control papers, which are design records, not a substitute for the look on the day. The home survey has not signed those drawings off and has not measured farm loads. Do not tell a lender the trusses were checked for either duty.
What should you ask your surveyor?
- How much of each truss could you see from that one bedroom floor?
- Were bearings, splices or later ceilings hidden from that view?
- Have you left farm loads and present house loads as not calculated?
What are the typical next steps?
- Do not treat the bedroom view as a reassessment of the trusses.
- Ask the solicitor for the conversion drawings and building-control papers.
- Instruct a structural engineer if the farm frame must be checked for house loads.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the bedroom ceiling is level, have the trusses passed?
No. A level ceiling in one room does not show the truss bearings or the loads the frame once carried. The survey did not calculate either the farm loading or the house loading now on those timbers. Neither the old farm duty nor the new house duty was calculated.
Does a planning drawing of the barn prove the truss sizes?
No. A drawing, if you have one, is a paper proposal. It is not the timber the surveyor saw, and it is not a calculation this inspection carried out. The trusses were only viewed from one bedroom floor. A drawing is not the limited view from that bedroom floor.