Mr Punter

Hi It is worth contacting your planners to get their confirmation of what "commencement" comprises. Some are happy to have demolition and access to site, others want foundations started or even foundations complete. Check and get the confirmation in writing.

That looks like quite a project. Was the design constrained by planners / neighbours? Our man @Russell griffiths has done an icf build near you. He could be a very good contact as he is a very capable builder.

If the site is flat, simple to set out, the height of the building will not be critical you could do without. I have bought a site in the past that had planning with no topo. The proposed house would not fit so we had to resubmit.

M & E engineer can be expensive and often better to get design and install for each element. MVHR / ventilation people can do their designs fairly cheaply. Bathroom designer will inform on that. Architect will normally suggest SVPs. You may need a drawing showing switches, sockets and lights, but you may be able to mark it on a plan and get the architect to add these in. M & E people are useful more for non-domestic, blocks of flats etc.

These are useful if the planners (or you) need to see the proposal in context with neighbouring houses. It also shows levels and features such as utility covers, levels and inverts. It can help greatly with setting out the building. You probably will not need it for planning, but the planners may ask for information, such as proposed ridge height, in relation to Ordnance Survey benchmarks, which you can get from the topo.

I would not worry about cold bridging for this as it looks like it will only be a lean-to. You do not need to mess around with the blockwork inner leaf. Just build the brickwork, fill with well compacted type1 to required level. DPM, insulation, concrete. Omit the screed. You should be able to get the concrete OK with such a small area and the brick to work to.

A friend has a number of investors and he pays them 8%. He is in the property business and will, say, use the funds to purchase a house, add 2 rooms in the roof under PD, let it as a small HMO, refinance with a commercial mortgage, repay the investors and keep the change.

You can buy flood resilient air bricks that close up when the water rises.

Most 50mm wide stainless mesh will do. If the cladding laps down a bit you could have a bit wider. Fix to the batten with stainless staples.

Box in the rad pipes the same height as the skirting - 150mm? Quite satisfying to do. Where they come out in the corner, box right to the ceiling. Those steps look too high. The top step would be better set down so it is 1/3 the way between levels. You may need to reduce the bottom step as well so you have 3 risers instead of 2. If they are not right, sort them out now or you will have to live with it always.

I don't know why would make it so you cannot have a visitor who has a walking frame or wheelchair. I have done level thresholds in block paving and they seem OK.

The hinges were bad but the latch was mental! Agree to them having the chance to put it right. Maybe they outsource to others and are not aware of some issues.

I think it can if you add water and leave it for a while (weeks / months) but I think the lime putty is supposed to be better. Never used it myself and it is quite a specialist area. If it is conservation type work do not use any cement at all.

Putty lime with no cement.

Yes, some car body filler would work. Paint it and the metal with some black metal paint and it will be your guilty secret. Are you putting an ACO along the front?

Send it back it is awful. It looks like they used a pocket squirrel.

@joth can you post up photos when complete. Do the birch ply carcases have exposed edges and inset doors? Maybe do a new thread.

I have a 3 point motorised lock and Videx door entry. I guess there may be a way of adding remote access.

It is heavy, really dusty to cut, needs special tools to cut and special fixings, sparky will curse you, the FST stuff is not easy to apply, although it will hold a screw you need to pilot first. Positives - if it is kept dry it is very durable, impact and noise resistant. They use it in double layers for high security institutions. We recently just used Knauf Soundshield Plus plasterboard as it is good for impact, fire and acoustic rating, loads cheaper than Fermacell and simple to fit and skim. We did double layer 15mm on walls and ceilings, which will give all the decrement delay you need.

Are you going to leave much of it exposed internally? I imagine it is expensive, so a shame to cover it in plasterboard. If it is left exposed I am interested in seeing how you run services. Any pictures you take along the way would be appreciated.

Gallows brackets are often a much cheaper way of removing a chimney but you MUST make sure they FULLY comply with this https://www.labc.co.uk/news/how-to-get-it-right-removing-chimney-right-way-video-showing-wrong-way and as others have said, if it is a party wall it can be really dodgy.

4m should be acceptable as access. They may require a turning head at the top. It is probably worth including for large vans / deliveries. A 100m2 bungalow should be non-controversial. You could get an architectural technologist to do the drawings.

I am interested that you chose CLT. What are the benefits / your motivations behind this?

There is a lot of glazing and exposed wall perimeter for a passivhaus. It does not look like it has been designed to the standard and it will be very difficult to try to make it work later. The rooms look OK but overall I am not that keen on the design. A lot of work is needed on the elevations.

I have used Fermacell in the past and I would never use it again. It is a nightmare to work with.