Thorfun

ok, then I'd say it is on the expensive side! as those things not included will be quite a hefty chunk of cash. we hired a local groundworks company who did the digging and insulation under the slab and they then subcontracted the basement build to another company who came in and put up the formwork, steel, waterproofing membrane and poured the waterproof concrete. then when they left the groundworkers built the internal walls and put on the block and beam top. it worked out a very cost effective way of doing it. you can view how we did it on our blog: glad to hear it. and we love photos on here as they speak a 1000 words or so the saying goes.

welcome. sounds like an amazing space. there are a few on here that have basements and I'm sure @Bitpipe will add his experience in due course. I've just gotten to watertight stage with our build and we have a basement and, tbh, I don't think £500k is far off the mark for a 400m2 basement when digging down 4.5m! we have 3m ceilings and 120m2 and, if I subtract what I think the foundations without the basement would've been, I estimate it cost us about £1200 - £1250/m2. so £500k seems about right to me although I guess it all depends on what that includes. if it's all internal walls, watertight with 2 forms of waterproofing and all the light wells and dealing with the water etc then I'd say it sounds reasonable. I've heard stories of £1000's a week just on pumps to keep sites dry. good luck and I look forward to following your progress should you choose to post about it! ?

there are consultants for anything you could want and PHPP is among them. this might be a good place to start. https://passivhaustrust.org.uk/members/map/

I can only presume so. Like @SuperJohnG I paid using Paypal so can only confirm that but I see no reason why a CC should be any different. I just checked my PayPal history and it took 3 days for the refund to come through, but then I ordered on Christmas Eve so that delay could've been due to the Christmas period. but I definitely didn't request the refund, it did just happen.

it's not taken off at point of order. they will have sent a PayPal refund for the VAT.

yeah. they did for me. I got a refund for that EU VAT very promptly from Latzel. DPD then send you a payment request for the import duty before they'll deliver the goods.

ended up doing this room flush to the windows. tbh it wasn't a conscious decision I just realised that by the time I'd finished it I'd forgotten that I could've put battens! sorry @pocster. think I'll just do the same throughout now. save me a lot of time and faff adding extra battens especially as the majority of my windows are 2.1m high.

I presume that Travis Perkins and Toolstation are part of the same company then?

this is exactly what I was going to ask! I remember @ProDave saying that 25mm battens plus the 12mm plasterboard fits a 38mm backbox perfectly. am I misquoting you Dave? But I also note that many others have used 38mm x 50mm battens. as an electrician @ProDave which is best (or your preference) and why?

Internorm, Norrsken, Gaulhoffer, Idealcombi and Rational. there are so many companies that some got cut just coz we didn't like the pushy salesman. others just coz we'd had enough of walking around a show! not very scientific and we may have missed a potential gem but we just couldn't visit them all.

if that's aimed at me, then we found the Velfac windows just didn't feel solid when opening and closing. but everyone sees things differently so, seeing as windows are a very big ticket item normally, the best advice I can give is to go and see LOTS of window companies. the big shows are a great way to see the majority but then there are others that don't go to the shows so a visit to the company/reseller is required. we must've visited/seen at least 10 different window companies and 'tried' them out at shows before whittling our choice down to 5 or 6 that we got quotes from.

we saw Velfac at a show and discounted them early on as we didn't think they felt that good quality. might just've been us though I guess but, in my opinion, Norrsken are vastly superior quality but I am a bit biased seeing as we bought Norrsken! ?

cheers @nod. great info as usual.

thanks for this alternative option @nod! but it has raised a few extra questions. 1. how thick would the adhesive need to be? i.e. how much more of the frame would be 'lost' by sticking the PB on? 2. what would your preference be if you turned up to a job? the batten solution that @pocster used or the flush PIR and sticking the PB? 3. what adhesive would be best in this situation to use when considering that there will be an AVCL on top of the PIR so the PB will actually be sticking to that?

it's EPS300. our SE said the thickness didn't matter as long as it was EPS300. so I did the calculations and decided that 300mm EPS just gave a stupidly low U-value and the 200mm was sufficient for our needs so decided to save some money. the PIR was just something to staple the UFH pipes to! it was cheaper to use that than to pay for more screed and click tracks for the UFH pipes. we're going for 190mm Frametherm 32 between the rafters and 100mm PIR (maybe 90mm, I will revisit those calculations in due course) below the rafters. UFH on the ground floor and basement but don't ever anticipate using the UFH in the basement. I am really not worried about heat loss tbh, but I see a thermal bridge and try and resolve the issue. the curse of a mind that troubleshoots for a living! pi$$es the wife off no end as every time she talks to me about something I have to find a solution to it.

are we playing basement top trumps again? ? 200mm EPS below basement slab with 25mm PIR on top of slab under the screed and 200mm EPS outside basement walls. for areas above ground that don't have the basement underneath we have 300mm EPS under slab. 140mm Frametherm 32 between the studs and 80mm PIR inside the studs.

yep. and timber isn't a bad insulator anyway.

still a bit of a cold bridge there though through the timber frame stud, into the batten and then in to the house. but I guess there'll be AVCL on top of that all anyway so I wonder how much of an impact that bridge will have

summin' like this? as is at the moment: with a 25mm x 50mm batten: with PIR: I could then add some 25mm PIR between that batten and the corner batten like this?

yeah. sorry. on the front of the PIR will be AVCL and service cavity with battens. but I'm not sure about on the side? how does one attach plasterboard to the PIR there?

cheers. I thought it might come down to personal preference so I'll ask SWMBO. don't want to end up like @Adsibob and I presume it's ok to screw PB into the side of the PIR? it's not like it's going to split like screwing in to the end grain on wood?

Hi all, I'm not far off starting our internal PIR insulation and have a quick question as to what's the best way to install it against the windows, flush or a gap? e.g. Flush: a gap: obviously, flush reduces the cold bridge but after adding AVCL and tape and plasterboard and a skim would that take a stupid amount off the profile of the window? whereas by leaving a gap for the plasterboard to sit would allow more of the window frame profile to be visible. or is there a better way? or is it simply personal choice as to how much window frame you want showing? any advice is greatly appreciated.

yeah. definitely easier on a new build rather than renovation. but if you're having the roof re-tiled then it makes it easier (and potentially cheaper on not having to use tiles under the panels).

we used arbtech. very happy with their service and prices.

yeah.....we're aware ?