G and J

I’m under the impression that it takes very little to constitute the above. I wholeheartedly applaud you waiting for the right one. As for kits, that I’m less convinced about.

We are about to self build for the second time in 35 years. I think it’s a brilliant thing to do, but… I also think it’s a stressful thing to do, big sums involved, either lots of people involved or if not then megatons of work for yourselves, maybe a bit of both, it’s a long slog, and it’s hard sometimes to imagine the end result and thus be confident on all the myriad decisions along the way. And I don’t think it’s an easy way of boosting your equity either. All these downsides….aren’t I a ray of sunshine! Well I am actually, because I would also say that if you, throughout the process, keep in mind why you are doing it, then you are likely to end up with a home that’s much more suited to you and yours than you could ever purchase. Where you know (and hopefully love) every nook and cranny, and although this is a bit of an ego thing, you might also have an individual, unique house you can be proud of. When we were planning to buy our plot, over three decades ago, I went to several builders for quotes for the whole thing. One of them asked why we weren’t doing it ourselves. I answered that it’s because neither of us are in the trade. He laughed, called me a rude name, and said that even if you’re in the trade you have to learn all the other trades, so I’d have one more trade to learn than others would. “So what?” he asked, and in hindsight he was so right. Plot finding is v hard though, especially in our lovely but overcrowded country, it’s taken us a third of a century to find our second plot, so good luck in your search.

That’s a timber frame cavity wall, and an excellent u value to width ratio if I’ve understood it correctly. May I ask why you didn’t do that?

@JackOfNoTrades was that with the cement board sheathing directly onto the OSB3 or was it battened first?

Woo hoo! I’m celebrating, I finally managed to produce a sensible looking ubakus wall build up dooberry thingy. Now I need my homework marked….. (should I be worried about the red colour on the drying reserve measure? It goes away if I turn off the PIR layer).

Goodness, thank you for sharing that. So your OSB skin is on the inside and is your main airtight layer in your wall. Not sure we can go that route due to fire resistance - I’m still not sure how I do address airtightness. Your framing timbers are I’m guessing circa 5.1m and your floor is hung from the side of them. Was there a specific advantage in doing that over what I think is called a platform floor? (I mean where you build downstairs, the floor sits on that and then you build upstairs directly on top of it.)

It accounts for how all the high energy hard sell is paid for for the SIP providers. I’m guessing the same is true for frame kit providers too. In our case the fire resistance requirements put SIPs at a disadvantage but I think that there simply isn’t a mature market for blank SIP panels like there is for other building materials, otherwise the cost of a SIP self build would be closer to stick built. With markets, volume is such a dominant factor. I think you’ve shared your wall build up before JohnMo, but I can’t find it. Would you mind sharing it again?

Well, I thought I’d feed back on all my investigations. Revising my earlier SIP figures, to include a cement board skin, the costs for the frame, not including barrier membranes, battening, cladding, PB or skim, roof trusses, and in the case of the SIPs, also excluding the attached garage (no idea why, but they all left this off): 1. Get a company in to do the lot and it’s just over 104k. Game over. 2. Have a different company make it in factory and deliver it for me to erect and it’s about 56k. 3. Buy blank PU SIP panels and build it myself, buying in joists etc. from other suppliers will cost about 39k. 4. Stick build it (excluding labour), assume cement board skin and osb3 skin, 140mm rockwool in frame, 50mm PIR inside that, 18k. Crumbs. I think my way forward is clear then….

We are keeping the larch down the sides for aesthetic reasons, and we are told we can, albeit treated for fire retardancy, but that we have to frame with cement board rather than OSB3. This is from the architect rather than the SE, as we haven’t got an SE yet. I think in my castings it would be prudent to assume both OSB3 and cement board, just in case… Thank you for sharing that.

We are replacing a bungalow which is on a narrow site which thankfully doesn’t taper front or back. Whilst we are extending the footprint a bit at the back we are under no illusions that the external finish has to be no nearer our boundary on either side than the current bungalow. But yours is a point well made.

Always good to understand your exit strategy, however heartbreaking….

Don’t know what a covenant consent thingy is, but… Presumably you’re settled with the fallback position of being limited to that outline planning permission (I didn’t know that still existing), or if not, you’ve an exit strategy of selling the plot if you can’t get what you want.

Ummm, did the parish council support your planning app?

One of the things I like about buildhub is that I learn from others mishaps, so I’m grateful to you for sharing as I can easily imagine me doing that. So I’ll sleep soundly in the knowledge that I’ll make other, perhaps worse mistakes. 😕

Noted. Makes perfect sense.

Reduced batten spacing makes perfect sense. As for the latch, we are thinking we’ll get it delivered treated for both fire resistance and this sacrificial coat stuff that helps it age prematurely (much like the self build process does to us all lol). We are of the perhaps naive belief that it will be maintenance free thereafter. No high level painting either, I’ve done enough of that over the last third of a century.

Thank you JohnMo, will read up.

One thing I have been pondering. Lots of peeps appear to include service voids - I’m looking at 25mm and it will have cables only in the main. But no one talks about stuffing insulation in those voids. I think the cable ratings will be fine even allowing for insulation, but is there another reason why it’s not done? Perhaps it’s just not worth it (I can’t work out how to drive ubakus yet but I’ll will!).

Can you imagine how awful it would be to be a planning officer? Bet you get a lot of nastiness thrown at you.

Oh no! Party Wall Agreement! We need these on both sides!

We’re softy Suffolk southerners in a sheltered location, so the general benefits of the enthalpy exchanger sound limited. The only possible factor is that I use a CPAP machine with a humidifier (sleep apnoea). Might just mean I have to turn up the wick on that and fill it up a bit more. Small price to pay for a comfortable, dry house.

Thank you, one of the issues with building is that one has to make many, many decisions that are so hard to reverse later, but MVHR seems like a no brainier. Where I’m less confident is whether we’ll need an enthalpy thingy which can be sorted later. We get used to nicer environments very easily - do you now notice when you go to houses that are more humid?

Oh crumbs good point. Are you thinking flex too much at fixing or otherwise? As I’m fixing the vertical battens to the cement board presumably I could double them up to reduce the span for the horizontal battens. This is the profile we are looking at….

That’s not the look we are going for and it would reduce room sizes by a fair bit too. And it wouldn’t help construction fire risk.

1m from the boundary I believe.