Sounds good Katymac.

Honestly I find £6.5k to remove asbestos-cement (not high-risk unbound asbestos) hard to swallow. If so, I'm shocked, and so will farmers up and down the land. Check again.

Why lower the walls? - as I said, loss of useable volume (can equal mezzanine floorspace if nec in future) that you already have and will actually have to pay extra to get rid of, incl having to demount and later refix your roof trusses. Why not leave as is? 2 or 3 more courses of strawbales; OK more volunteer mouth-days to feed; not a problem structurally as all is unusually well stabilised by the existing walls, compared with normal strawbale methods; additional heat-loss area insignificant.

Roof 1m wider/longer - does that mean 50cm at each edge? That only just covers the straw-bale thickness - why not go for an additional 50cm overhang all round - will make you boring old shed look good, and shelter the walls. Once you've done the labour to extend 50cm, an additional 50cm is nothing, just a bit more Onduline and rafter or whatever. Have you thought of extending (or making future provision to) part of the roof to form a covered play area/porch on a couple of telegraph pole columns?

Assuming you're going to be insulated to excellent standard (no reason why you shouldn't, starting from scratch), then your sources of heat loss, in order of significance will be:
1. accidental air leakage (unless you really go to town on that - again no reason why not)
2. conduction through windows and doors (taking it that you'll have nice fat squishy better-than-builders-merchant-ordinary airseals)
3. floor (but see below)
4. roof
5. walls, if straw-bale
Maybe 3, 4, 5 might be in different order. Anyway, heat loss through your straw-baled walls will be the least of your problems, so you can afford to leave them taller.

Notice that none of the above list of heat-loss sources has anything to do with the height of the spaces. It's a popular misconception that taller spaces require significantly more heat, at any rate when insulation is good. Sure you have to heat up more air but that's done in a flash, is negligible compared to heating up the surrounding solid materials.

Even with intermittent use, given excellent insulation, it's right to go for the 'stays pretty warm all the time' strategy, rather than the 'whack it up just before opening time' strategy. Actually, with heavy blockwork wall surfaces exposed internally, plus maybe heavy solid floor surface (or thinly overlaid), you've no alternative. The surrounding surfaces don't have to be re-heated every time - they stay pretty warm, even if heating goes off or goes to a reduced setting overnight. In this scenario, tall spaces really won't take any more heating at all.

If you really want to minimise heating costs, then as I say, really go to town on airtightness - that's where most of your remaining heat loss will go, once you've insulated really well. This takes knowing design and specification, including sealing all the many difficult/hidden corners and junctions - hairlines and pinholes are the target - don't skimp - the result will only be as good as the weakest point. Also long-term durability - forget reliance on any kind of sticky tape. Then your only ventilation is deliberate. If anyone suggests that leaving the building leaky is a good idea for ventilation, just blow in their ear. Order windows without those awful plastic trickle-ventilators; order 2-stage cockspur latches or preferably espagnolette multipoint locking; then open windows a crack or a lot, or look into passive stack ventilation (can someone else advise?) or for even more economy and superb, cool freshness, invest in heat-recovery ventilation. That would work very well in your barn, as it's shaping up.

Do you feel you must have a low horizontal ceiling,like 2.3m standard house height, for any other reason? Sounds depressing. Cheapest possible is to use the underneath of the roof slope as your lofty ceiling, no separate horizontal ceiling. Generally open-plan, partitions up to various heights as needed. If certain rooms must be completely separated, then put a ceiling over just that bit, maybe make that bit into a mezzanine gallery for the kids to rest or make a den or something. I do think you could do with some spacial concept input - your own practicality plus Amazon Nails' constructional priorities won't necessarily add up to something delightful.

Floor - what's the existing like? Level enough to use, or all up and down, typical agricultural-style?

Given the heavyweight stays-permanently-warm scenario, then the floor and the gound under it can heat up over an initial period of days or even weeks, but then stay as a great reservoir of warmth. To achieve that, you don't need underfloor insulation, just good perimeter insulation, provided you're going to dig down all around the perimeter. You'd lean something like 15cm of closed-cell plastic foam insulation - foil faced Cellotex or unfaced Kingspan - vertically against the foundation wall, from ground level down to say 1m below, before re-filling the trench with earth, or blockwork foundation wall.

If you're not digging down that deep, then do the above to as deep as you can, plus underfloor insulation - but not all over the floor area, just in a band say 1.2m wide around the perimeter.

Doing the above, the floor might still feel a little chilly to sit on, so maybe you're thinking of some kind of wooden (or inevitably I guess woodgrain printed MDF laminate) floor. This can be quite thin and the heavy floor underneath will still lend most of its benefits of massiveness.

Architects (apparently) get 7.5-8% of a project my size but would rather work on one that costs twice as much as mine (iyswim) - I expect to pay between 7K & about 10 K for the architect - I just can't find one

I'm still getting to grips with the post before (about the floor)

I really don't mind paying - I have rung numbers of of the bible....honest - I must have been in touch with about 22 architects (they are too small, too big, not my thing or you have to spend £1000's more) 2 were interested but too busy

Yep (over by Yarmouth)

Posted By: fostertom (or inevitably I guess woodgrain printed MDF laminate) floor.

I don't think so

Marmoleum (if I can afford it)

Carpet isn't really ideal for the nursery

But I will be buying second hand carpets for the non child bits (office/staff room)

Marmoleum - I have had a quote for £6K fitted

£30 psqm fitted

Hmmm

Like cork - how do you prevent the children to picking the bits out?

The cork tiles are normally sealed with a sealant like os hardwax finish which is very tough.
Interesting range of prices you have been getting.

insructions for treatment: http://www.osmo.co.kr/hardwax.htm

The finish is made up of natural oils and waxes. No solvents.

Hi there

just a couple of points to bear in mind, If its been a grain barn the floor will be one of 2 types 1:- solid concrete 2:- suspended brick either will have been built to support a substantial weight of grain so will be quite deep. Walls will also be built to support a good depth of grain so I'd guess the steel frame has substantial foundations to stop them splaying outwards. I've seen a few of these converted and I know you're very keen on straw bales but were you to clad the building externally with timber then you could add as much insulation as you like, it would let you retain the internal blockwork wall which could then be either rendered or could have plasterboard stuck to it. As for higher up were the outside clad you could simply do an internal ply and plasterboard facing with insulation between the two. Roof wise talk to the farmer most of the corrugated "fibre" cement roofing ends up in a hole in the ground which a lot of farms have for more general waste. Its criminal the costs you are being given for removal and disposal of something thats legal to remove yourself as long as you are sensible and this then simply gets bunged in a landfill site anyway!

Hi Guest

What sort of insulation would you use, how much would it cost and how much would the wood cladding cost?

The floor is concrete

I still don't think there is a frame

I am getting a structural engineer to look at the roof trusses & do a calc to see if they will support a new roof & a suspended ceiling & I will ask him about a frame........

I am also getting a third quote for the asbestos from Norwich rather than GYarmouth

Will this work?