ETC

You won’t find that specification on Google!

I think Elvis has left the building!

It’s a Visqueen product and is - I’ve been told - radon proof. Easiest way to install a radon barrier is to: Build up your sub-floor blockwork to the underside of your slab level. Fill voids between rising walls and finish off with well compacted hardcore and 50mm of blinding. Lay a 1200 gauge membrane (minimum gauge for a radon barrier) over the complete footprint of the works. Overlap and tape all joints. Use top-hats for services. Set up a 150mm slab complete with anti-crack mesh and bear the slab 100mm onto the sub-floor blockwork. Pour the slab. Put a stepped DPC around the perimeter of the slab.

In all honesty I think you need to appoint a good architect. Not an architectural designer - an architect who knows how to build, design and who knows the Building Regulations. I get the impression that you are not content with what your own designer has come up with otherwise why would you ask for feedback from an anonymous internet forum. If you have been advised that you need fire doors downstairs and a wacking great big void to below is acceptable you’ve been misled. A two storey dwelling doesn’t need fire doors unless you are creating a protected staircase and why go to the expense or inconvenience of doing so if you don’t need to. I do think you are missing a trick - a great architect will create a building which is a joy to live in rather than just individual spaces. You could have had an atrium in the middle with courtyard (like many Mediterranean houses) or used the shell of the building as just a shell and created a series of buildings within the shell. I am by no means a fantastic architect but I do consider myself to be pragmatic and practical perhaps to the extent of boring but I can recognise talent and to be honest I don’t think your proposal is the best it could be. I’m also fairly versed in the Building Regulations although in my UK region we are slightly behind England - we would be less flexible in relation to fire control. Don't get triggered - the members here are genuinely interested and have offered some - largely - practical advice. Good luck and I hope you get sorted.

Yes they do.

Might be cheaper to get someone who knows how to use CAD to draw it for you.

The gutter is too low and falling towards the building. Raise the gutter to the underside of the flashing.

Vary the bed depth.

No. If the steelwork requires FR speak to British Gypsum or Harmon for the correct way to fire protect steelwork.

Have to agree. Organ grinder and monkey come to mind. No offense.

No.

Should have been two beams. You'll also need a stepped DPC/cavity tray above the beam.

Did not know that…….good to know about mould……

Nope. Does the same job. Just need to undercut the doors to allow for whole house BV.

Just look at the legislation-it will say what the inspections are.

Install a roof light where you need the head room. You’ll get an extra 100mm easily.

Look at what U-Value you are trying to achieve and then decide - I’m surprised that 75mm of PIR will comply - but I would be leaning towards pumping the cavity with insulation and if required dry-lining the inside with insulated plasterboard. As I said before (and got slagged-off for) you will be at the mercy of whoever is building your walls to get the PIR boards correctly installed.

Building Control need to see the DPM before you place insulation or concrete. There are a list of Statutory Inspections but assume that BC need to see most works before they are covered.

And what nobody has mentioned is that you really shouldn’t build joists into a party wall.

Just a thought…….why don’t you appoint a structural engineer to help you? Just saying.

PIV system. https://drimasterexpress.co.uk

1. You’ll need to separate the kitchen from the staircase as well as separating the void over the kitchen from the upstairs. 2. How are you going to clean all that high-level glass? 3. Hall is massive. 4. Some rooms too small/too long. 5. I could go on.

Where’s your gutter?

No - I’m suggesting you take up all cavity walls to the flat roof. The only wall that’s not a cavity will be the wall between the staircase and the bedroom which you can either build as a traditional timber stud wall (insulation between and inside with a vented and drained cavity or take the 215mm wall up and insulate the inside and clad the outside. Once you’ve the cavity walls built up clad the outside with vertical and horizontal battens to create the look you want.

Also why are you building a cold roof? For the corner use a Keystone post and lintel system - simple.