ETC

Where is the site boundary? Where do you enter the site?

Sketched without reference to a site plan. Going to give it another lash. Watch this space.

My attempt at a simplified version. Two wings with standard pitched roofs - single storey open vaulted ceiling for the kitchen/dining/living room and 1.5 storey for the bedroom block. Not unique but works. OP version in red behind.

Sorry - not a fan. Far too fussy in plan and in massing and could be simplified and made a whole lot cheaper. The hipped roof will need a shed load of steel probably including steel hips. Not sure where the front door is and having a tapered tread staircase is something to avoid if you can. Can you post a site plan so that we can see the context.

Parapet gable wall.

Consult the posi-joist literature for sound and fire resistance requirements.

Flat roof with a slight fall to back and front.

Chaplin?

Bad idea having all those voids in a slab - move the pipe below - or above - the slab. Where it is above use a concealed system (Geberit) and when it's below get it out of the building as soon as possible, don't over complicate connections (think about blockages and access) and bed all pipes in an appropriate bedding material.

Lol @ “whether to involve planning and BC”.

Good luck.

A cut roof (loose rafters and a ridge beam) should be cheaper.

Doing the birds mouth on the trusses?

LRS need to be 30mmx5mmx1000mm long at maximum 2000mm centres.

They don’t look long enough or thick enough for LRS. Plus they need solid timber blocking between them. Wha5 centres are those rafters at?

Not for a cut roof they won’t.

What are those metal things on the gable wall?

Irrespective of the p/a this project will be limited to the physical space available - that’s why I am suggesting something like the Kingspan Kingspan OPTIM-R or something similar. The poster will only get a U-Value that can be obtained by the floor build up with an insulation with the greatest thermal resistance. A bit of research is required.

From memory I wrote this in response to being able to commence a building project as cheaply as possible without having to commit to getting a project built. If you just want to “commence” the works, have proof that you have done so and postpone the works for a period of time just dig a trench straight through the grass - no need to strip the top soil or grass away. Once BC have “commenced” the works you can fill in the trench. Digging the trench in the “wrong” place ticks the box for BC but makes sure that the “real” trench(es) won’t be compromised if left undeveloped for a period of time. You will have to speak to your local BC and Planning Departments in relation to what they deem a “commencement” to be. Where I am what I have described is adequate for our BC to determine that the project has commenced. Our Planning Department will accept the BC commencement as their commencement too. I wouldn’t think the ground workers will mark out the building. They may do but in my experience they turn up and expect the house to be marked out.

No - incorrect. This post is about insulating the ground floor and the poster has posted: “Current floor construction from top to bottom: carpet, 18 mm chipboard, ~50 mm wood battens @ 400 mm centres, concrete beam (180 mm) and block (100 mm), 300 mm void, DPM, ground. Therefore I would not be breaking any existing DPM.” What I am suggesting is removing everything from the top of the block and beam flooring and installing a floating floor above this - OP has approximately 68mm-78mm to play with (carpet (8-10mm) + 18mm chipboard + 50mm battens). Replace all this with timber flooring (approximately 18mm - 22mm) and insulation (whatever space is left). If I had time I’d draw a sketch - but I’m a bit busy at the moment. Staircase and doors not affected.

Not necessarily - work from the existing floor level down and increase the floor insulation accordingly.

You won’t need a handrail or guarding to the bottom two steps but because you have a split level on the principal storey you do need a handrail - on each side because it’s a circulation route. As others have said if the difference in floor level is more than 600mm unfortunately or fortunately you will need to guard the drop and as others have said you will need infill panels with uprights less than 100mm apart. I really don’t see a reason why you can’t build something a bit “tastey” that complies. Post a couple of drawings and I’ll have a bash at designing something .