Mr Punter

There is a large difference between the price of Thermowood and Pine and I guess this is reflected in the cost of baking it. Don't underestimate the transport, handling and storage costs.

Can you just double up the sole plate on the timber frame and increase the building height by 38mm?

I think you need to leave it another couple of weeks. Get the ceiling and the door reveals tacked and plastered and the whole room at least mist coated.

Perhaps you can just ignore the joists and fix through to the lower OSB. 18mm OSB has a pretty decent pull-out rating. Just make sure you have the correct screw lengths for the differing insulation thicknesses as the screws will only be threaded at the end 60mm, The tube washer type fixings look good as the screw will not pop through the waterproofing if the insulation is compressed.

It is true that you won't get enough flow for 2 showers with the combi you have but the accumulator will help with pressure and flow rates and hot / cold imbalance. If you really want to run 2 showers at once you additionally need either a hot water cylinder or a high flow storage combi,

What would you use in this circumstance? Some sort of cement board as the top layer?

Where would the moisture causing the condensation come from? I have seen some roof insulation where they bond a thin ply layer to take membranes etc and they have BBA.

Sounds better than firrings. What fixings are you using for the top sheet of OSB?

Not read all but a cold water accumulator with pump is often recommended for pressure/ flow issues.

I have used RAK sanitary ware in the past. Very good value and the quality seems fine.

You may find it difficult to mount the post you are looking at without it being a trip hazard. How about an overhead door closer with hold open?

+1. It seems like the chimney and steel are the only structural work you did. Was it signed off by Building Control? If not, get a Structural Engineer to inspect and suggest any remediation, get it done and get Building Control signoff.

No you need to delay the kitchen fitters.

Before Grenfell, Kingspan and Celotex were BBA certified for use on tall buildings.

The landowner is responsible. It may be that they can persuade the owner of the gas main to stump up some compensation, especially if the main is not shown on any asset plans and / or there is no wayleave in place.

The domestic alarms for new build are normally mains heat and / or smoke detectors with integral sounders and battery backup, interlinked so that they will all activate. They are installed by the sparky. Battery only alarms are not acceptable for new build. Commercial alarms have a central control panel where the building can be split into zones. The sensors and sounders are often separate. They may have break glass type call points. They normally need an annual service and installation from a fire alarm specialist.

You could well be right and it can be modelled. In some places you can just open a window to prevent overheating but in others it will still be oppressively hot. The 7 figure budget is rather vague. I would not expect this to cost less than a £1M with a main contractor but you may not want to go too crazy. There is a Corten house just down from me that was on Grand Designs. I am not a great fan of the finish and it is not that easy to work with. Make sure you get detailed costings, especially on the non-standard bits like the retaining wall and the cantilevered roof canopy, before you apply for planning consent. The interior stuff you can change if you need to but the exterior form and finishes is part of the consent.

An existing and proposed plan may be useful. For foundation depth you can normally just do as per the current house. I really dislike macerators and if there is any way you can achieve gravity drainage then do that. There is no issue with water and drainage in the same trench. Water will normally be at the bottom, at least 700mm below ground.

From the renders the sun will be over half way into the living room. Someone on here @NSS? has Sage glass, which can be tinted automatically to reduce unwanted solar gain. Maybe worth considering now as you have the funds.

Normally it is the Gross Internal Area - measured from the inside of the outside walls. Internal walls and staircases are counted in this. I find £/m2 useful both for build cost budgeting and for sale and purchase prices. I would not take the word of an architect when it comes to construction costs unless they have been in charge of a number of very similar schemes.

You can get RF ones in the Aico range which I think are considered acceptable. More money though compared to hard wiring but can get you out of trouble.

We have done something similar in the past. We used an old well as a chamber that we fed the roof and some other surface water to, then pumped it up to a drainage ditch at the top of the drive. I very wet weather the ditch does fill with water, but it is because other properties did not maintain a culvert when they added their access drives.

Same here. Our sparks were very keen on the non-replaceable ones. With your GU10s you can just swap out the lamp if you want it brighter / dimmable / new tech or higher efficiency.

I always separate out the purchase costs for the site. For the rest of the costs, fees, prelims and contingencies are about 16% and service connections 4%. Per metre I am currently working on £2,300. If you want to see what your profit or loss is, you also need to add notional disposal fees (agents and legal) plus finance and valuation costs.

A couple of members may have some ICF blocks: Nudura Durisol