Mr Punter

I would prefer contractors to read / look at install instructions rather than wing it, which a lot do. I once had some chippies install expensive cement cladding. They decided on a 155mm lap although it should have been 180mm. Cost me an extra £1,800 and some of the junctions looked crap.

Good luck with the curtains and blinds!

If they sued for breach of covenant they would need to establish their losses, which would be minimal. It would cost them a fortune to get to court and they would probably lose.

Be good to get him to detail the pricing eg prelims, foundations, demolition, brick / blockwork, floor, roof structure, roof covering, elecs, plumbing, plastering, carpentry, kitchen fitting, decoration and tiling. You can easily see how much of each is complete and pay accordingly.

Is the staircase open to the rooms below or does it lead to a hallway, with doors?

Are the opening windows the IdealCombi tilt / turns? Do you need to turn the key to get the window into turn mode? If so, they will not be suitable and I do not think they can be easily adapted.

You can buy 6mm treated laths from most roof people.

They normally ask for a fire door between house and garage. You can see why I guess. Make sure the frame is the right spec as well.

No there should be no condensation in the gap, although it is common to have some thinner insulation under the rafters to prevent cold bridging.

If it is black it will not be noticeable. You could just stick it to the top of the vent. I assume this is not a hipped roof, so you can do this bit in isolation. Make sure 6mm is enough.

Yes, enough for a waste pipe. Also space under units.

Where we are almost all the roofers use the same lead man. He is very reasonable and does really neat welding etc. I sometimes ask the roofers to exclude the cost of any specialist leadwork. If they get the job they liaise with him and he bills me. They still do soakers etc.

The upside is no string - if you like the minimalist look. These took ages to finish compared to a timber staircase but like you we had Bison in to do the floors so it was one less thing to consider and straight away we had safe access between floors.

Yes the concrete stairs are expensive. I have clad them in timber before and extra for glass balustraded and stainless handrail. Also lining up treads with floor finishes can be tricky. You often have to screed the hollowcore to take out the camber, as well as batten the underside for plasterboard. Carpeted timber stairs are practical and inexpensive.

The architect on my scheme has put in a pocket door. So annoying, especially as the rest of that level is done in blockwork. AHHH!!! I think I will just leave an opening if BC accept it. It is second only to curved walls as an expensive ball-ache.

In terms of time, good workers on price can earn £400 a day if they graft. I recently had a team of 3 in for 5 days for site preparation at a cost of £5,000. They worked from 7:40AM to 5:00 PM with about 40 mins total break. They did the required demolition, cleared and disposed of all the timber, carefully stacked the paviours I needed to reuse and left the site neat and tidy every evening. The price was a piss take but worth it.

Was it the case that you did not agree a price or rates in advance and just let them tell you how much they wanted when they finished? If this was priced and you agreed, you should just pay.

This sounds like a reasonable fee and it is reassuring that they are trusted and reputable. Some architects I have dealt with have slightly bizarre ideas or agendas and can be difficult to deal with.

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.