Conor

Roof and floor insulation are two ways to save lots of cash for a job that can be done at relative leisure and doesn't need much skill or tools. You'b be wanting 100mm PIR between joists and another 50mm under them, as a minimum. Aim for a U value of 0.15-0.1. Spray foam is an attractive option, but pricey, and can be done very badly and inconsistently.

That's what I did. Was impossible for him to give an estimate. Turned out to be 50% over our time estimate, but that was largely side to the decision to do a lot more muckaway rather than store on site.

If you're not increasing the catchment of the gullies (i.e. not increasing the hard standing area) then the works are classed as a repair and no additional permissions or regularisation is required*. *From my BCO a few years ago when we did an extension and had to relay all the external drainage.

For a normal cantilever building using standard techniques, you want the anchoring wall to be double the length of the cantilever*. You don't have that. I'm not sure this building is constructable without extreme (expensive) structural solutions not normally used in standard residential construction. How much detail has your SE looked at? At a guess, steel framed building with lightweight wall panels (sips) would be the obvious option to minimise the engineering required for the cantilever. What's the constraint that allows to build over land as a cantilever but not put in posts/supports? A couple conctrete columns would knock several tens of thousands off the build cost. * I am not a structural engineer, just a lowly environmental engineer ?

Let's take a step back from the heat loss / demand etc provided by companies trying to sell you something. How well insulated is your house? I'm tired of hearing horror stories of heat pumps installed in houses that simply aren't insulated enough to be effectively heated by a low temperature system.

Bargain. Road closures are not cheap. I think we've done three on a project in work and it's cost €50k so far. My connection was £2300 and that was literally 10ft of digging through my neighbour's garden to bury the existing service.

No, couldn't get it to work due to loadings exceeding EPS300 capability in several places. Went for a standard ground bearing slab with ring beam.

Best asking around through people in the trade or visit sites. Most stuff like this changes hands through word of mouth.

The guying doing our ICF was originally a concrete shutterer by trade. Says there's not much in it but prefers the ICF work as it's physically much easier and less to go wrong.

We just used ICF with 200m concrete core. Seems a lot simpler than the details above. We stuck on additional insulation on the outside face to get us down to 0.15. Just sheets of PIR with expanding foam, then geomembrane before backfilling. If you don't want to use ICF, I'd go with @Thorfun detail.

Welcome, go for it. I built a block walled garden brewshed with insulated slab, GRP flat roof, made a door and fully rendered. I'd barely laid a block before this.... It did take 2 years tho lol

Sorry @yoshi, no idea.

As @Bitpipe says, you'll be disappointed in what can be salvaged and reused/sold. I spent an age dismantling our bungalow by hand, apart form the bricks, haven't found a use or interest in the slates, timbers, flooring etc. All the metal went to scrap. I would have saved a lot of money and time if I'd just knocked the building over.

Yeah. Used them to map underground utilities in dense urban areas ahead of pipe laying works. Or, as above, a pipeline CCTV and detector.

Ground penetrating radar. When we did it we charged £800 a day. Probably cheaper to dig a few holes.

Glulam seems to be an obvious alternative. Can be made to your exact spec and can look good (if it's your kind of thing).

We did, but because there was obvious oil contamination. Whole lot cost about £700 I think.

D&B is a good option, it's the default for big infrastructure projects. You do however need to have a very detailed and robust spec. There is an incentive for the D&B contractor to cut the spec and corners that the client won't notice. Therefore, independent inspection and signoff for stages is critical. If you don't know what type of plasterboard should be going in or what type of insualtion, then get somebody to check that for you. And make sure all parties know the spec inside out before singing and you'll get on grand.

Being in Northern Ireland, all of those costs would be a fair bit lower.

My builder charges £80/m² for building ICF (standard ICF block for a simple wall inc openings). I think the Amvic blocks work out at about £35/m² for Joe blogs.

Architect says set the joists on and use nogins to brace them together. Span is only a metre anyway. there's chipboard then liquid screed on top. I'll screw every other joist in with a 6mm screw just to be sure.

Think I'll check that with the architect, this was his design and I'm only now thinking about how to go about it!

We have two box beams with 15mm plates welded to the underside to take the floor joists for the mezzanine. It's 6m long and need joists at 400mm centres, and another section about 2m long. Notlooking forward to drilling all those 6mm holes. I only have a cordless drill, I'm thinking I'd need to buy a higher rpm corded drill and a big box of bits? Any other suggestion? (First image is actually of the plate that will take the bifolds, but you get the idea)

The utility companies will need to agree wayleaves with the owner. I'd look at alternatives.

Expanding foam all the way round each sheet, then 140mm zinc plated screws with 36mm countersunk washers. 600mm spacing, so three rows of 5 screws. I'll probably put a few more in to be safe. Then a bead of foam on the edges of the block before placing the adjacent block. So a couple dozen per sheet. Screws are driven in about 30mm or so and filled in with more foam. This is to prevent moisture reaching the screws and causing rust issues. With a waterproof silicon render, moisture shouldn't be an issue anyway. Alternative would be stainless steel screws and washers, but these are significantly more expensive. This is all from advice from an ICF contractor that does it all the time. EPS arriving next week so will post up a blog entry.