Hullo Masklin, it does sound like a tricky situation, and I'm sorry to hear about these additional costs. Building work is always expensive to begin with, and additional and unexpected costs are never welcome. In respect of whether there is scope to obtain costs for this from your architect and structural engineer, this will most likely come down to the original appointment, their scope of involvement in the project, and whether they where direct appointments with you - or whether the SE was appointed through the architect. If the architect and SE were appointed to undertake planning and building regulations drawings with no exploratory or invasive works (ie stripping back existing structure in the house to assess structure before the project was tendered) then there will have been a number of reasonable assumptions on their part, which will only have been assessed when a main contractor started. The conversion of the attic would have added some additional loading to the property, but certainly less than adding a whole additional storey. There is every chance that additional bedroom space at this level would have less weight implication than someone stuffing their attic full with storage. SE's are notoriously cautious, so their assumption for the attic should have taken into account any additional loading, and if an existing (previously completed) opening needs to be reinforced, it might suggest that the existing opening was not designed appropriately to begin with. The flaws in existing structural design would generally fall into 'unforeseen' items, which is generally where contingency funds are intended for use. However, as others have suggested, if you are unhappy you can always pursue this further through the ARB, or RIBA (if your architect is a member of these bodies) or through the body that the structural engineer belongs too - but it is always worthwhile starting a discussion with the architect and SE and asking them to clarify how this happened. They will no doubt want to try and address this and have the opportunity to resolve this with you direct. Check your appointments with them, and what they were briefed (and paid) to undertake on your behalf. It might also be worthwhile trying to source any information you can about the original works and structural beam that got installed. Hopefully there will be a positive outcome from it all. Good luck! K :)

I wonder if you need a designer. They will be able to help manage the project, can pull in the right professionals as you need them and may be able to help secure some trade discounts. In my opinion the change of layout with this project is reasonably minor but the purchases (kitchens, bathrooms, flooring, window covering, lighting etc) make up a much bigger part of the project.

We had a 'planning consultant' he was about a fifth of the cost of the architect, as to be fair we knew exactly what we wanted, just needed to know how to get there. They say they offer:- Architectural plans for planning permission • Architectural plans for building regulations • Architectural plans for listed building consent • Sectional drawings of fenestration • Design and access statements • Justification statements • Landscaping plans We paid him for drawings, I think he employed a structural engineer for the steels calcs, we have 13 steels in the house now, as we took a lot of walls out and converted the loft (was a bungalow) Hope this helps, Julie

Hi Rhian Am i right in understanding that the window is shown in the wrong position and the bathroom is shown on plans as in the wrong place. if the former is incorrectly positioned then the engineer will have to redo the calculations to prove the position works and importantly that you builder has the correct information. the adjustment may not be significant, but he/she will need to verify this for you to have building control signed off for the former, if incorrectly positioned. if it is merely a room shown incorrectly, and the dormer is in the right position then the engineer will not need to adjust any calculations. hope I have understood you issue. if you provide a photo of the plans ,it may help in better understanding your problem. best Rowland