Crofter

The current sketches are for a box 9x7m, with an asymmetric pitched roof. It's a fairly straightforward shape really. I'll stick some pictures up once I've tweaked a few details in my SketchUp model.

I had a go with Onshape, but it was a bit frustrating. It looks like a good product if you invest the time. However after a bit of googling I discovered that a common problem running the web version of SketchUp is that it won't work unless you have at least 4Gb of free space on your HDD. I deleted a few things and voila, back in business! First draft of my new house project incoming...

Woodfinishesdirect are good, they carry a wide range and I think they have a calculator that helps you see how much you need. Osmo products are very good but they aren't cheap. Also worth checking the usual DIY places (Screwfix, Toolstation, Wickes, etc).

Or in my case, just materials and tools. I never employed a joiner last time and I don't expect to this time either. This is what I'm concerned about. Last time, being exempt from regs, I could just build it the way I thought would work best. I already had a fair amount of knowledge about TF design and just applied those principles, but there weren't a lot of calculations involved. It was a very small house (50m² footprint) and I used 6*2 studs and rafters primarily for insulation depth so I was confident that it was plenty strong enough. We have a local guy who I've already approached, and he had a good reputation, but he says he's moving away next year and my project might not go fast enough for him.

The problem is that when you open the door to light it, you break that circuit. Once up to heat, the stove draws fine. It's just lighting it that's a problem. What size is the one you're familiar with? I do think part of my problem is that my stove is so small.

There is no frame supplier. I'm building this exactly the way I built the last house, by buying a big stack of timber and using a nail gun and chop saw to turn it in to a house. I may use engineered joists (I used them last time and they were great to work with, and very cost effective compared to solid timber). But I may not end up using trusses. Ground floor is likely to be an insulated slab. I may be facing a bit of a reality check with my costs. The first house (2015-17) came to £40k total, excluding the plot, including VAT on everything because it was exempt from building regs and ineligible for VAT reclaim. The new project will be bigger (33% bigger footprint, plus rooms upstairs) but will be lower spec (uPVC instead of aluclad, no WBS) and eligible for a VAT reclaim. So I'm hoping that it will be only slightly more expensive to build. Of course there's been a fair bit of inflation since 2017. But £5k would be a huge chunk of my budget. I did all my own drawings for PP last time, and intend to do so again. How feasible is it to also do my own BR drawings?

Stain is a separate product to paint, it's generally green or brown and it soaks in to the wood. Used primarily for waterproofing and protection, but also gives a uniform colour to the wood which hides rust marks from nails etc. Satin paint is simply non gloss paint, completely different product and purpose. Oil is a specific timber treatment, historically linseed oil was used. The unscrupulous may use engine oil. It's just to protect the wood from water penetration. I would definitely never suggest using engine oil because it will stink, it's carcinogenic, and it will probably leach back out of the wood over time, getting on anything that touches the wood.

It's a new build house. Provisional sketches are leading towards a 65m² footprint, 1.5 storey. Timber frame, corrugated steel roof, larch cladding on the walls (or possibly a mixture of larch+steel). Basically the same as how I built the previous house.

Embarking upon self build no.2. First time round was building regs exempt, and was entirely a DIY effort. I'm confident with designing the layout and structure, and much of the detailing- I've done it all before, although I'm not trained or qualified in any way. I'm considering employing an AT to ensure compliance with regs. 1- is this the correct person to use? 2- is it feasible to go DIY? Or will I get hopelessly bogged down in SAP calculations etc? 3- how much should I budget for this?

My experience of a WBS in a low energy house is not especially positive. It's a very small house (43m² internal) built to approx twice building regs minimum u values, and as airtight as I could get it (I was building regs exempt so didn't do a test). I have MVHR. The stove is a 3kw unit with external air feed, via a vent in the north elevation. In certain conditions it can be an absolute pain. I learned early on that to stand any chance of getting it to draw, I had to leave a window or door on the house open, because the airtight house just can't support the draw of the fire when lighting it. If you don't get it to light first time, you're best to let it go completely out before you open the WBS door, otherwise you'll get all the smoke blowing back in to the room. I think the intrinsic problem is that it's a 90% efficient stove and it's at the lower limit of what is actually possible in terms of size. There just isn't enough heat going up the flue to get it to draw strongly. I may try adding an extension to the flue to bring it higher above the house ridge, and I could try repositioning the intake, as i do think that in strong southerly winds there might be some sort of vacuum effect going on. But it's all a lot of hassle for something that is really just there for aesthetics. The next house will not have a WBS.

I do have a pitched warm roof. But I don't have trusses, as all the cross beams would represent too many penetrations and thermal bridges. I've got a ridge beam and cut rafters instead. I wouldn't discount the idea of layering your insulation the way you describe, but I would seek more advice on it. It's a higher condensation risk but it may not be a show stopper.

It's certainly a higher risk for interstitial condensation. But I believe it's possible to make it work. On my build I did full fill wool between studs/rafters, and a layer of PIR on the inside. Seemed the safest method. I'm in no way a qualified or trained builder or engineer though.

It's very rough and coarse grained, you might find that out soaks up paint like a sponge, and the paint will be liable to crack and peel over time. I would stain or oil it instead.

So far, I'm enjoying doing some rough sketches to figure out what we want from this house. I'm not an architect or engineer but I think I have a pretty good idea of what I want. Last time round, we went down the 'portable building' route which meant we were exempt from building regs. This time round we want to build slightly larger, with an upstairs, so we can't go down the same route. And anyway this house is for us to live in and we need the VAT reclaim. I understand that this means I have extra hoops to jump through. I'm happy enough doing my own drawings through the planning permission phase. In principle I'm pretty sure I have the knowledge to actually design the structure and to comply with the space requirements of building regs. But I'm not sure if my SketchUp files and hand drawn diagrams of the detailing would pass muster with the council? I'm also not really sure about meeting the energy efficiency part of the regs. I understand the principles and intend to, just like last time, build a very high efficiency house. But I gather that this isn't quite the same thing as meeting (arbitrary?) rules, and then there's the matter of actually proving it. I would like to tackle at much of this myself as I can, but maybe it wouldn't be a bad idea to get some professional input. Should I be talking to an Architectural Technician? Like I say, I'm not looking for somebody to design me a house, but I might feel more confident if a professional had gone over my plans and checked that everything will be compliant.

You want to design your layers in such a way that you eliminate condensation risk. So on the inside you have a vapour barrier, then your insulation layers need to, ideally, become progressively more vapour permeable as you progress towards the outside (e.g. PIR first, then mineral wool). Then you have a breather membrane which should keep most moisture out of the structure, but which will allow any moisture that does accumulate to escape. And finally your cladding which acts as a bulk rain shield. What you must avoid doing is creating a completely sealed volume from which moisture cannot ever escape. So you have one VCL, and either side of that a pathway for moisture to get out.

Manners please chaps. 'Sweating' is the product of poor design, poor understanding of condensation risk, and poor application of a vapour control barrier.

The little house we built has a lot of west facing glazing, and it's insulated to near PH levels, so on a sunny afternoon the temperature inside can fairly soar. However we're on an exposed hillside and on such days there's always a sea breeze blowing hard. Opening doors or windows on either side of the building drops the inside temperature to ambient in a few minutes.

I can't get it to run on my ancient Lenovo X220. Which is a shame, because the old version used to run just fine on this exact laptop.

Last time round I made extensive use of Google SketchUp, which at that time was completely free and worked just fine. I got it handy with it and could knock up 3D models in a few minutes. It really was invaluable in figuring out not just the basic layout but also many of the fine details of the build. Unfortunately things seem to have moved on, and my laptop no longer seems to run it- it also appears to be an online only program these days. Is there anything else out there that I should consider? I just need to build simple models, I don't need loads of textures or the ability to export to a 3D printer or anything like that. And the closer the UI is to SketchUp, the better, as I don't want to have to start from scratch...

We'll still own two properties with WBS so getting rid of wood won't be difficult. I'm not completely against fitting one, but it's a very obvious way to save some money on the next build.

As others have said, the extra cost depends on design and labour factors. On my very simple build it really didn't add any cost at all, other than the MVHR itself, was was about £700 plus ducting. I had a simple box with a warm roof, so minimal jobs in the membrane. You need a VCL membrane in a TF build anyway, I just made this my airtight barrier too. I spent a few quid on tape for the windows.

Wonderful tune from a fantastic musician.

We're at the very earliest stages of thinking about this, but at the moment we're considering copying some of the features of our previous project, and making some changes. Such as: - corrugated steel roofing. Definitely a win, for aesthetics, cost, and speed/ease of installation. - larch board on board cladding, same reasons as above - large windows without glazing bars. Thermally better, cheaper, just better on every way tbh. But this time round we'll have some non openers. - as before, high insulation and airtightness, and MVHR - open plan and vaulted ceilings where possible - bamboo flooring, painted MDF skirts/arcs. A premium look at low cost, also durable and repairable. Where we would diverge from the previous project: - uPVC instead of aluminium clad timber windows. Shock horror I know. But having had both types, it's just hard to beat plastic. We've had a few problems with our very expensive alu clad windows, whereas the uPVC was bombproof, and about a third of the price. - no opening glazing in the weather-facing elevation. It's just asking for trouble. - no woodburner. In a properly insulated house it's unnecessary, it's extra cost, mess, air leakage, etc. We'll fit a mini split for heating, and maybe V2L for power cuts, which really aren't that common with us. - PV and battery storage - we'll probably build on an insulated raft rather than a suspended floor

Last time around, people were building houses for under £500/m², and fancy stuff was maybe £1200. I think my own build worked out about £800/m², which was inflated by the small size and relatively high spec. What are the ball park figures these days?

Ok so not just a downstairs WC, but space for a shower too. That does ring a bell. What are the rules about how close a WC can be to a kitchen? I think there's a bit of an urban myth about needing two doors in-between?