saveasteading

Tiles? I’d expect a caravan to have a thin steel sheet with some polystyrene under it, and then ply for some strength. But I see your photo, so perhaps otherwise. I'm guessing, but that would need care. You have to consider if a hot flue could cause a fire. An insulated flue would be essential as a minimum. There are special flashings for flues to metal roofing or any other product, so it is doable.... with great care.

I thought it was OTT at first too but it's an agreed price for the work so can't argue. They've clad another smaller roof too ( 15 x 12) and I suspect the crane had gone and the handler was used for that. Plus the garage roof had to be stripped first and there's other steel to do too. I'm on hols so missing this fun: my favourite bit of any steel job. Overall that's impressive in 4 days of wet weather on a steep roof. We can now take away the buckets that were under the holed garage roof. note the string line for fixings precision, and the ridge filled with foam.... nice.

As I've often said on here. I prefer tanalised pine with a stain. Neutral stain locks in the colour. A fraction of the cost and can be repaired/ replaced / adapted at any time. That's just me and my experience on commercial work. The family projects use cedar which goes grey, because I'm not in charge.

That's going to be OK. There is no bending stress at the end of a simply supported ( not built in) joist. But be sure to cut neatly and not extend the horizontal cut. There's another option though: to counterbarten under the joists, or add another layer of plasterboard.

This pic makes the scale clearer.

Good plan, and take photos as it won't be visible.

After a dry summer and minimal progress, we are getting a roof on at last... in foul weather. Fortunately the cladder doesn't mess about and has hired in this very serious kit. Hence 350m2 on plan was clad in 2 days. Huge crane with panel clamp, big mewp and don't forget the forklift off to the right.

The caravan steps at Argos are good. But you'll need a slab base first to get up to your floor height.

@webbythewebsterI'm seriously impressed with your research. You must have come across lots of promotional material, with the criticism difficult to find. Is science or research your skill? @SteamyTea if I recall, superfoil had their own way of assesssing insulation properties, thus getting improved numbers. Something to do with heat escaping from a box.. I'm wondering if your example of the greater area of slope may explain their trick.

You have understood and explained beautifully. As has @JohnMo It is highly marketed, stopping just short of untruth. Bubble wrap for sheds or greenhouses. In case he needs further convincing... reflective surfaces need to reflect back to an air space to perform. Squeezing lots together doesn’t work. And condensation could cause problems. Interesting that it has dropped in hype from 'the most amazing development,' to the Aldi aisles.... For more insulation, add more fibreglass to the loft floor, perhaps the opposite direction to what is there.

To me these are normal things and not complicated. More importantly the same applies to any builder. Rafts are expensive. Not to be confused with a simple slab. There is nothing wrong with bearing your structural walls on a standard slab IF it offers the same resistance as as the deeper footings. That is for your SE to agree and then for you to impose strict quality control. Is the exposed ground undisturbed and compacted? Is your sub base properly compacted? Concrete thickness, reinforcement and quality of course. The slab will likely be thicker too, and I'd forecast, more expensive than with footings.

In what way? It's standard construction and means all your structural walls are sitting on the same strength of ground. The only issue I can see is if you wanted a power floated slab. But it's a house not a warehouse. What am I missing,?

Galvanising is not essential steel only corrodes if wet. Yours should never be. Paint it with an expensive product made for the purpose. As it will be concealed it doesn't have to look good. Beneath the base plate is the highest risk. Make sure all detailing keeps this dry. If it is on grout then bitumen paint it.

It's for your Principal Designer to resolve. Their only excuse is if design detail and changes have not been presented to them. I think you must fit as thick layer of foam board on the outside, as works. May only be 10mm but do it. As @Nickfromwales. Then also insulate thre inside face later. Filling the box section is pointless. That will fall far short of any target U values but is much better than nothing, and the area is small. To help tick a box, use the U values for windows as your comparison. Then add more indulation somewhere else. But ask the PD.

Names please?

OK so that is simpler. The only problem is that 3m span. I've got one in our kitchen that must be close to 3m wide. The blind concertinas up on a string. It was made specially from an adapted kit, and the fabric part was specially made by a friend. It felt expensive at the time. Then I fitted it. Shop around.

Indoors/ outdoors/ manual/ motorised? Ou of interest I looked for one on a Spanish diy shop website. 2m width maximum is the main issue. External Blinds in plastic, €140. BUT Add roller, pull cords runners, mosquito net... all specials. And labour of course. So I'm thinking your quote isn't too bad. If it was a garage door it would cost £1200, but maybe a lot more at 3m wide.

Did you find that the differences were fairly clear? Would they talk cost, even in general terms?

I think that's OK. A joist has very little stress towards the mid height. It also reduces towards the ends.

That's what I was wondering. The exhibitors must do well enough out of them with the £££ leads. Are they mostly kit builders? Plus planning agents, architects? I'd love to overhear the sales pitches. Yes, but the one I went to recently, was very strict on business only. Quite rightly so as otherwise you wouldn't get near the exhibitors for public wanting free advice. I got lots of good contacts and info, and a year's worth of pens. Sometimes there are in-between exhibitions.... that's where I've encountered lying, ignorant agents for rubbish products.... no names here.

Presumably the previous owner went though such thought processes. Do you know them? Can you ask? Have you looked at all the planning documentation? It will be online along with any previous applications. At least you might design the house in such a way that another house may be possible in the future. Basic questions. Who did the planning application that got permission? Havd you / Do you intend to engage professionals at this stage?

Don't just charge ahead on these. Good value starts now. Eg you say septic tank is going in. Make sure this will fit in to your completed project. Not best value installing a septic tank now and then abandoning it for a treatment tank later.

Firstly I'd say that you should expect this to take 3 years. Going faster costs money. Secondly. Homework. You will get help on here but not a free design service. Become expert. Meet neighbours, become involved locally. Look at other projects in the area. Read BH. Read the building regulations. Thirdly. Your design at this stage must consider the practicality and cost. Now some questions. What size of house do you plan? Do you know if your budget is suitable? How much diy do you intend? Do you have a view on the build method? Don't despair.

Did they give you numbers? Basically was there some radon or none?