Benpointer

Norrsken asked us whether we wanted to reduce the window sizes or make sure the external cladding comes up lower than the window opening. We opted for the latter and they provided us with this helpful diagram for the amount of cill clearance needed.

They pinned it into the clay. You can just about see a couple of pins in the extreme bottom right of the second pic. Not sure what they were tbh thin plastic rods maybe.

The excellent SE we contacted on Thursday to design the depth of our foundations came back on Friday with the answer - deeper than we wanted at 1.95m in the corner closest to the neighbouring oak (15m away) but his quick response has saved the schedule. We need to add clayboards in the corner nearest the tree but overall it could have been a lot worse. His rapid turnaround was brilliant and it meant we were able to crack on this week. The groundworkers had already discounted Monday as I suspect they thought they’s be waiting for the SE but through the rest of the week dug all the trenches and on Friday we had 7 lorries of readymix poured. The only issue was they hit a shaley layer at the bottom of the deepest trenches, so with the BI’s agreement they poured a couple of loads of concrete in on Wednesday before digging out the rest of the trenches. So now we have all the foundation trenches filled with concrete. Next week the groundworks team plan to concentrate on the drains, installing the sewage treatment plant (we’ve gone for a Kingspan Biotec 2) and ‘losing’ the massive pile of spoil we have, across the paddock. Block and beam floor to go in the following week. Target for completion of the groundworks is 27 June, so three more weeks allowed. I’ve checked in with the timber frame company (Turners) and they are still on schedule to deliver and erect the frame between 7 - 18 July. I have also finally managed to get some quotes for scaffolding and that’s scheduled to go up 1 & 2 July. The company we have always previously used have singularly failed to respond to my repeated requests, so I gave up on them and got a couple of other quotes in, and selected one. Windows, roofing, screed, plumbing and electrics contractors all lined up - I need to sort out some plasterers. The first indicative price I had for boarding out and plastering was… Ouch! Hoping that might be an outlier; it’s certainly more than Homebuilder’s Bible was suggesting £ per m2. In other news, we’ve found somebody who wants the timber garage, which we need to remove to create enough space for deliveries. He, his dad, and a friend are taking it down today.

Thanks for the quick replies. It's a very quiet rural area but there are houses each side so I'm not sure about acoustic boards - but probably will go for them. The reason for the odd mix in the roof is the rafters are 254mm easi-joists which we're having blown with cellulose, VCL below, then we will have 100mm PIR below that to give the 0.1 u-value we want. Also going to run the MVHR duct through channels in that 100mm PIR. Service cavity below that and then the PB. Might have to go for 15mm on the ceiling then as the joists are 600 and the service cavity battens will need to be below them.

Am I ok to use standard 12.5mm plasterboard for the walls and vaulted ceilings throughout our single-storey timber-framed new build? I was planning to do just, that with a skim, however one of the plasterers we have contacted for quotes has suggested we should use blue acoustic PB throughout. However the Building Inspector has insisted we fit acoustic insulation to all internal stud walls and the vauled roof make up includes 250mm blown cellulose + 100 PIR, so I feel we will be fine on the sound front. (Plus it's just the two of us most of the time.) Also, I thought I saw somewhere in the building regs that we need to use fire rated PB on the external walls - but I can't find anything about that now I look again. Our external wall build-up is PB + 25mm service cavity + 50 PIR +140mm frame (with 120mm PIR) + 50 external cavity, then a mixture of timber cladding or render on render-boards. Thanks!

Are those diagrams the Aquarea L series or just illustrative of similar ASHPs?

Thanks, I've sized the heat demand using Heatpunk at 5.3kW so a 5kW is not technically quite big enough. But you've got me thinking: You sized at 6kW and it's twice what you need... so this sizing business is not necessarily that accurate. I might be sizing too high, I might be sizing too low. How would I know? Overall, I'd prepare to pay for a bigger pump and some over-capacity than risk having a cold house during the next 'Beast from the East'. I am told by the guy that's going to do my MCS certification that these Panasonic units modulate down efficiently.

Looking for some more advice please guys. I am looking at a 7kW Panasonic Aquarea L series but finding their literature less than clear. https://www.aircon.panasonic.eu/MT_en/model/kit-wc07l3e5-wh-sdc0509l3e5-wh-wdg07le5-kit-wc07l6e5-wh-sdc0509l6e5-wh-wdg07le5/ These units seem to be 'hydraulic split'. Presumably that means the refrigerant (R290 - aka butane?) passes through the wall and the part of the heat pump that releases heat sits inside the house (a plant room in our case). Does that mean noisy machinery inside the house? Is having R290 inside a timber house a great idea? Also what is Bi-bloc versus, presumably Mono-bloc? Sorry for the dumb questions - I seem to be having a bit of a Mental-bloc. Thanks for any help.

Re pocket doors. I realised I posted an out of date plan - we've made some tweaks since then, in including losing two pocket doors. We may potentially drop some of those yet. One reason for using them is that I'm a wheelchair user and pocket doors are easier to open and shut in some situations. @SteamyTea Vaulted ceilings are u-value 0.09, see below

Geoff Cole from PWCR in Shaftesbury. Comparable price to WDA (we spoke to them too). We felt Geoff listened and understood what we wanted, and built on that with some ideas of his own.

Demo notice?? Thinks... are we planning a demonstration? Ah, a demolition notice, for the timber garage (nothing else is coming down)... Eeek!! The council website says: "Exempt work No counter notice is required for the following work: ... a greenhouse, conservatory, shed or prefabricated garage forming part of a larger building" I'm classing the timber double garage as prefabricated, so I'm going to assume not. But good shout.

More likely sticking his spade in the ground surely? 😉

Not sure why the BI can't use the tables any more but the SE was more cautious than the NHBC tables, see below. We haven't done any plasticity tests - was hoping to avoid the cost, which I guess we have done.

Our groundworkers arrived on site as promised on the Tuesday after Spring Bank Holiday. Raining all day of course! Though tbf it’s fairly light rain. They made a good start removing a concrete slab left over from a long-demolished, clearing the oversight and creating a temporary spoil dump site on the paddock. Three issues this week: An unexpected armoured cable is discovered on day two - our groundworker Marcus is unsurprisingly cautious. Quick call to our electrician Nick. Nick thinks it’s probably the a redundant feed from the neighbouring house to what was their workshop - should be fine. He comes to inspect it and concludes it is dead. We explain that the groundworkers have asked him to cut it if it’s safe to do so. “You want me to cut it?” he asks, slightly incredulously. Yep. Nick angle-grinds through the cable - cable is dead, electrician is still alive - problem sorted. Second issue: We found out on Thursday that the Building Inspector unexpectedly wants a “Structural engineer to design depth of foundation due to clay soil and the nearby oak tree”. Both our architect and groundworker expected that the BI would be happy to agree the foundation depths based on the NHBC tables. But no, the BI is no longer allowed to do that he says. So, we are in a hole so to speak but just not sure how deep a hole... A rapid scrabble to find a SE who is able to help and help quickly, as we want to dig the trenches next week. On Thursday we got hold of a chap we used for another project 15 years ago - he thinks he could help in short order. We await a result. Third issue: We had hoped to keep the existing timber double garage for the duration of the build, for storage through the build. But the groundworkers are worried about access and off-loading our beams for our B&B floor. The timber frame and window companies also think the space is very tight. I conclude the garage will have to come down - now. It was a mistake on my part to try to keep it; we could have dismantled it carefully during the ‘phoney war’ ahead of construction proper. Annoying. Fortunately our PP includes demolition of this garage so, we are fine on that front. Our chippie knows someone who may want it and will dismantle and remove for nowt at their expense, hopefully in the next two weeks. Failing that the groundworkers will knock it down with a digger, but it would be a shame not to recycle it. Edit: The SE has come back with the foundation calculations over the weekend (what a hero!) so we should be all sustems go for digging the foundations next week. Hurrah! Pre-start "One day my son, all this will be yours" Making a start. In the rain obvs: End of week 1. Happy with that!

We’re starting our build so I thought I’d attempt a blog. I can’t promise to keep it up throughout the build but I start with good intentions. Apologies for the inevitable typos along the way. A bit of background: We have previously done a lot of alteration and refurb projects for our various homes over the years, the most recent a major eco- refurb and extension of a 1960s bungalow. Last year we decided to bite the bullet, sell the house, buy a plot and build. We sold in October, bought a plot in November, and engaged some local architects to create a design to our brief. The plot is 0.85 acre on the edge of a Dorset village. It already had PP for a conventional 3-bed chalet but we wanted a near-Passivhus contemporary single storey house with vaulted ceilings - incorporating low u-values, ASHP, UFH, 3G windows, MVHR, PV, batteries... just about everything we could think of to make the house comfortable and sustainable. We’ve opted for off-site timber frame construction, clad in a mixture of timber and render, zinc roof. I am sure more of the construction details will get covered if and as I keep the blog going. I am a retired IT project manager so have decided to self-manage contractors rather than employ a Principal Contractor. I’m also a wheelchair user so, much as we would like to*, we won’t be doing much of the hands-on build ourselves (* Mrs. P. may not agree with that sentiment). We applied for fresh PP on the 28 January 2025, received permission on 1 May, and our architects submitted a building regulations application a couple of weeks later. We broke ground last week (see the next blog entry for details). For now, I attach a floor plan and some elevations to give you an idea of the build.