We are having a big renovation to our home (2 storey and loft conversion). The building regs guy came to inspect the structural aspects of the job the other day and queried our beam above the arch to our lounge / dining room (which is not part of the renovation). The Structural Engineer and Architect have said there is now additional design fees for this as it now needs a new steel as this area is now 'grossly over stressed' due to the new dormer loft above. We want to know if this 'assumed' aspect to the plans compromises the whole strength to these floors? We now are a 4 storey house as we have a basement too. Should our architect have mentioned this to the structural engineer? Should someone have picked up on this? We now have to have this installed later in project once the dormer has a bathroom ensuite installed. Should this beam be put in as soon as so we don't have major subsidence? Our builder says it could be done at the end of the job. That's about another month away. Any advice will be very much appreciated.

We are now half way through our build: 2 storey and loft conversion. Things are going well enough-ish. Building Regs have come to inspect the 'structural' part of the build only to find a few things they need changing. One is in the part of the house that should be 'untouched'.... namely the through lounge/diner. The arch between the once-two-rooms has had to have its' beam exposed to assess. They have now come to the conclusion that this current old beam is 'grossly over-stressed' and now needs to be taken out and a new one put in, thus a design fee. We are a bit cross that this didn't get flagged up at the beginning. It is now a 4 storey house and this particular steel is on the 1st floor/ground floor. We have been told by architect that it needs replacing as soon as. The builder advises and reassures us that it can be done in a month or so... no rush. But we are worried the weight above like the new sanitaryware in the ensuite will compromise the weight above. Can anyone advise us on the extra costings and the need for this urgency? Thank you.

@JenP - Yes it was a max budget of 40k...and I have every single budget meeting all around 38-40k; but then at the very end he explained his error which was on every sheet over the six months!!! This error (not carrying over the figure) meant he got the final totals wrong...and its now 50k. @jonathan - OK good to hear about your mum and I agree with everyone and will get legal advice. In my case, it wasn't even that the work hours or materials were higher, it was his calculations on paper - so the individual totals all work listed, but his actual final totals (and what he would advise me when I would have my monthly budget meeting) were continually incorrect - until he realised the mistake at the very end. Lesson Learned: Even when given a printed budget, always recalculate the totals yourself! THANK YOU FOR ALL YOUR ADVICE AND TIME - I will update here once I have an outcome. The good news is that I love my apartment and the quality of work is beautiful.

You need to consider how big the downstairs room will be- this will dictate one dimension of the bedroom. Likely the 45degree rule will dictate the other dimension- in turn this will dictate where the corridor needs to be. And if you are ok about reducing the size of the back bedroom consider instead of doing it in order to have a better bathroom consider reducing the size in the other direction in order to create an Ensuite