lizzieuk1

We used a Panoramic last time - quite happy with those but, will certainly take a look at Charnwood to compare, thanks for the suggestion.

That may be so but we're not going down that route this time. The last build we did we used 90mm kingspan (think porsche boxster in your walls just to pay for the tape!) as tighter site needed to avoid large cavity, along with lightweight 100mm blocks we achieved good u values but, we had so many weeks lost with poor weather it was painful, not to mention grim on site in the rain as took so long to get watertight. So many pros & cons with all the approaches so we can only weigh those up and go with what we're comfortable with.

Do you think its possible to screw plasterboard directly to the woodcrete? Thinking if we parged externally then that could be an option internally as ideally don't really want a void between board & blocks (we would then chase services in - or at least try to, any thoughts on that?)

Thanks Iceverge, All really useful points. Re the bifolds we've already decided to have large sliding doors instead, both for the point you raised and so we have a larger open viewpoint - realistically, with our weather, they will be closed for much of the year anyway!! The windows I think will be full panel with 'stuck on' bars (not my ideal but think far better thermally) we may well go with a more common 4 pane sash rather than 6 and certainly not 8. Need to research that a bit more though re thermal values, vacuum glass looks great but think still very expensive and looks only to be from timber sash companies, so, likely 3g instead as we'd prefer an aluclad type if possible, last build we had residence 9 in timber effect which we were quite impressed with (upvc not alu but very nice & for bit cheaper I think) We've had a stove for years and do love them, last build we had an external intake stove to protect the airtightness so will aim for that again and ensure a good seal for the flue outlet (no proper chimney stack, it will go straight out the wall in the 'mock' fireplace so will install pre-pour) we have quite a lot of trees round the farm so will have free wood for a fair while (and will plant more for future provision) U value we are trying to get as low as reasonably/practically possible not firmed up yet but ?0.12?, possibly will use an external brick slip sheet with in built insulation if budget allows. Will use the ecobrix 365 which gives a good 0.15 value to start though. Hear your thoughts on parapet roof, we had a lot of discussion about that, but we love the style and it will be natural stone copings made by hubby (we're wanting to incorporate lots of stone detail as have moved from living our whole lives the Cotswolds so more an emotive choice rather than practical!) we will have to concentrate hard on the detail for that to future proof it though! At least if we've built it we should know how to fix it in future! Thanks for the positive re the layout, I did take a lot of time designing it to work for us as a family home and as a home that can work as the kids & us get older, really pleased with how it's turned out though, as usual, we will need to work hard on the budget and do lots and lots of the work ourselves (whole point of self build though I think!)

That's what I thought may be the case re bc. I'm really thinking of how to integrate a patio that is at the same level as the FFL inside. We have an L shaped floor plan and will have sliding doors from both sides leading onto a patio so, ideally, would like it all on one level rather than stepped. I guess the rest of the perimeter can be stepped/sloped down and then the front & side doors can have sloping paths from ffl.

Is it possible to have a linear drain all round so that paving/patios can be level with FFL as well? Just been reading about the detail for the door thresholds and wondering if that's possible all round 🤔

Ooi how have others met the BC requirements for a level threshold? Was hoping to get level with garden paving but seems that's not an option with the raft design.

Yes, sorry I've caused confusion, what I meant was the dpm exits from under the concrete to finish level with the top of the concrete (as per your detail) not sure what happens under the Larsen truss though, does it have another dpc tied in or is the detail to minimise risk of water ingress between the insulation in the walls and the top of the raft insulation?(sorry I've not looked at TF details really so a bit ignorant on that aspect)

Yes, of course, was forgetting the dpc is directly on the raft top!

Gibdog - cant help with the query but your details aren't redacted on the pdf.

Thanks Ian, Not had a test done yet so don't know the bearing capacity. Hopefully it will be suitable. With the raft needing to be 150mm about Ground level, is that standard for all rafts? Am thinking of how to grade the 2 levels - do you raise the hardstanding around the perimeter then grade down?

This would be a great start if we could get away with a 450mm dig and 150mm type 1, not sure we will on deep clay??

Hopefully this works! Plans. Should add there will be a 2nd floor in roof space as wellplans.pdfplans.pdf

Thanks Iceverge. The discussion certainly has brought lots of things to light! All really helpful though. Hubby is a stonemason but not a brickie - big difference- his main skill set is in carving architectural stone such as church door surrounds, window cills etc but, he can build a straight, level block wall and has the skills to work to tolerances etc. Hence the woodcrete as it is an easier diy option than block but offers what we want, not perfect by any means but we have to weigh the pros & cons. We're pretty on top of the airtightness issues, dealt with those on previous build so a good idea of where we need to focus our effort. Will see if I can post our plans with redacted info.

Was there a reason you didn't parge the outside? Am thinking that way the entire envelope is airtight and you can chase services/fixings in without worry internally.

😬 Well I guess that ensured a great air test result! Will let you know once we're ready to go 👍

Lol, seems any build is traumatic! We don't have a start date yet, already living on site in the old house (5 of us playing sardines!) Would be very happy for ypu to take a look.

Thanks JohnMo, lots of great info from you that has really helped us. Will probably go for a parge coat, ooi did you wet plaster?

Thanks Nick. We're going with Ecobrix (Durisol) have researched for quite some time now and feel that fits our needs/wants best, have a supplier very nearby so can tap them for advice etc. Pro is no props needed but Yes, aware of the air tightness needs - we will likely parge coat externally & wet plaster internally, warm roof with loft rooms likely easi joist with blown cellulose but still researching that. Def will be having mvhr so vital we get the air tightness correct. Managed a 4 on our last build so did OK- block & stone with dot n dab- and LOTS of foam! No mvhr on that one though. Aiming for far better on this one though (def under 3).

Thanks Ian. That's hugely helpful, I'm wondering if I should reach out to some of the raft suppliers and get some high level estimates.

Many thanks Gus, lots to digest there. I'd say we have a fair experience level - completed 2 detached new builds in 2023, traditional block & natural stone build, (hubby is a stonemason) we used b&b floor and lots of very expensive Kingspan!! I project managed but we had a MC for the shell as not done one before- we were on site everyday throughout though as it was a learning journey for us(done a fair few refurbs and moving onto new build for our property business) We had lots of involvement right through planning (and appeal!) and with the regs drawings but we're led by the architect (more old school) so a raft didn't come into it as he suggested cost prohibitive - was a project to sell so we were more profit driven, though the houses were A rated & beautiful! This one is for us to live in long term, we will both be on-site throughout 24/7, so heavily involved, want to 'diy' as much as possible. We have time to spend and happy to ensure everything is properly detailed. Yes, the woodcrete is for us to diy (been back n forth with the options and feel it meets our needs longterm) I am quite a detailed person, I like to understand all the elements and make a well informed choice, if a plan says x then I will ensure it is x not x+1 so, I'd like to think we're up to the challenge but, you don't know what you don't know! And, never sure who's opinion to trust hence the post to gather info & opinion.

Is it because b&b is the easy choice for SE design? We're wanting to get the best solution we can without being ridiculous with costs.

The thought of piles and the cost makes me quote anxious! What was the cost of the foundation?

Thanks, that's basically what we did on our last new build except it was b&b, my real concern is the thermal values and thermal bridge detail at floor to wall junction, we really want to try to achieve something that is towards PH level and insulation inside rather than outside feels a bit contrary. SE has suggested we may need 1.5m footing on hedge side though yet to design - we've not done plasticity/bearing samples sp assume he is using worst case. The strip with slab detail is certainly in our 'comfort zone' but don't want to just 'go with' the easy option if there's a better way.

Thanks IanR, Ideally, we'll be better than regs, our last builds were A rated so aiming for at least that again especially as this one is for us to live in long term! We are hoping to diy as much as we can, the OH is a stonemason & pretty good on a digger! Will certainly ask the SE for some examples and see what he comes back with. Reluctant to pay him to design if a company that supply rafts will do this as a package (though assume thats at a premium?) Yes, hedge has been managed previously but has been left to grow for past couple of years (max height 4m, managed height 1.6m) as property was vacant for a while before us.