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Hi all Just stumbled on this forum, looks good so thought I'd join. I have renovated several homes and completed my first self build last year. I have made many mistakes, and learnt a fair bit along the way. Maybe I can help someone on here, I'm hoping to learn a fair bit too. Jay

A busy couple of weeks on site has seen the majority of the timber cladding finished, the rendering completed, and first fix / plaster boarding progress inside. The render system used by my builder is made by Mapei. Having prepared the area to be rendered (as described in the previous blog entry) a base coat : was sprayed onto the EWI, then floated by hand to a 6 / 7mm depth finish. Fibre mesh (which you can see at the bottom of the picture) was then pressed in the base coat to provide long term strength. The base coat was left for a few days to dry before it was skimmed over by hand to take out any imperfections / ensure the fibre mesh was fully covered. A primer was then applied (using a paint roller) to the base coated surface ready for the final coat: Due to some unfortunate weather, some of the primer got washed off in heavy wind driven rain. Reapplied where required, the house was then ready for the top coat. The silicone based top coat : came premixed in 20kg tubs, and looks very similar to Artex! At around £100 a tub, quite expensive as well! The top coat was sprayed on, and floated / polished by hand. Let's keep any comments about the sprayer clean! With an aggregate size of 1.2mm, the final finish is fine textured rather than smooth. Having completed the top coat, the guys returned the following day to touch up anywhere that needed it - very easy to do when your render system can be applied (like Artex) with a paintbrush - and to remove all of the protective film from the windows and gutters. They also took the opportunity to apply base coat beneath the bellcast ready for painting in due course. With the protective film removed, and the render complete, you really do get a feel of what the finished article will look like. It certainly (to me anyway) looks very neat and crisp. The only niggle really is the roof tiles, which although nominally the same colour, we clearly have tiles from two dfferent batches on the roof, which shows when the sun shines. Redland (Monier tiles) will apparently supply a tub of the acrylic coating used to finish the tiles to paint on, but local experience suggests that after a winter of weathering the difference will disappear. Drainage works and final landscaping are due to start next week, so all being well, by the end of the month we will have everything done outside. Inside, work is continuing, with Electrical first fix complete, Plumbing first fix nearly completed and plaster boarding nearly finished. The decorator is due in a fortnight, so we have a bit of time in hand to get everything finished off ready inside.

What I found with the "standard" timber frame kit suppliers, was as soon as you mentioned you wanted a really good air tight well insulated house, and you would supplement their standard package with extra insulation and air tightness detail, then they suddenly refused to quote. One said "there is no synergy between what we offer and what you want"

How about what I am doing? Timber frame with external (wood fibre) insulation board and render direct onto the wood fibre board. A lot of this typer of build is possible DIY if you are on a tight budget.

It was literally 1 block thickness that was all. 1 layer of foamglass blocks that was all, like oranjebooms pics with the thermoblock (which we might substitute for the foamglass actually). The foamglass isn't going under the internal slab, K103 is. We have a 50mm cavity then real stone outer.

Hi and welcome to the forum. You are clearly a serial self builder in the making, admitting you "made mistakes" on your self build. It takes at least 2 to get it right. And yes some pictures of your creations would be great.

Just the kind of person we love to see. Welcome! When does the next build start?

What U Value are you targeting? While foamglass is better insulating than other block work, it's not quite as good as EPS, so to achieve a Passive-slab type level of 0.1 U value for the floor and perimeter you'd need roughly 350mm foamglass. But that's not the whole "issue" with SIPs. If you wish to eliminate cold bridging and condensation risk on the sole plate then you need an additional external layer of insulation that drops down passed the sole plate. Where as on a thicker twin-stud wall or I-Joist wall there is an opportunity to place an EPS upstand under the middle of the sole plate so that the inner face of the wall is over the warm floor and the outer face is over a cold ring beam (or on the EPS upstand itself in the case of the twin-stud) and therefore braking the cold bridge, you can't do this with a SIP panel. Hence the need for EWI to isolate the sole plate from the cold side. My experience is that SIP suppliers are much happier about additional insulation going on the inside than the outside, but I believe quite recently Kingspan have started to support EWI on their panels. It's worth looking into the Potton PassivHaus that used Kingspan SIPs, their foundation was very complicated to resolve the cold bridging issues and IIRC they specified EWI to cover down passed the sole plate. Seems to me there are easier solutions with twin-stud and I-Joist walls. Plus you get to use an insulation with better decrement delay and acoustic properties.

I initially drew our floorplan up on graph paper, as I find this the easiest way of getting proportions and room sizes right. I subsequently spent a few hours on Sketch Up, drawing up a scaled 2D floorplan, and 3D renderings of the house which I used during pre-app planning discussions. The decision to go down the CAD route was primarily a pragmatic one, to have plans that were: I used one of the main online free lancing sites to find the chap who drew up my CAD drawings (his details are on the plans linked to on my blog). I sent him my 2D Sketch Up floorplan from which he produced floorplan and elevations of the house and detached garage in PDF and DWG formats. He also did my site and location plans for me.

Hi Jay, Can you post some pics? Be nice to see what you created. Welcome?

I would get something over those window openings. while waiting for my windows to arrive, the openings were sheeted with OSB to keep the rain out. That looks just like "ordinary" chipboard to me. Even the green "waterproof" stuff won't stand up to much. the only one that will is something like Weyrock (the name will be clearly printed on it) that has a sort of grey waterproof coating. Get the windows covered, let it dry out and see what it is like. Put a straight edge over it and see if the joints have swelled.

Standing charges are high as gas use in current house is £1500 a year. Probably around 50-60000 kWh. I haven't moved into my new super insulated house yet. Plus as mentioned elsewhere before my wife has 2 baths a day! We are 400sqm so running about 150 kWh a square metre which I guess would be consistent with the EPC, although the house has never been assessed. If it was just me the costs would be lower but a happy marriage is cheaper than lower bills! The break even for your gas contract versus mine will be around 17500 kWh a year, so looks like you are on the right contract for you. My electricity usage is similar to yours. I have a 4kw PV array so my costs are dominated by gas. I just put my current house which is a 15 yr old timber frame house into the heat loss calculator. It looks like it would have something like 4-5x the heating costs per square metre of the new place. These are guesses on the current place vs the new place. They give a figure consistent with my current energy usage. - Walls 0.3 vs 0.15 Roof 0.16 vs 0.12 Windows 1.6 vs 0.75 Air changes/hour - 1? vs MVHR - Not sure on this one. But the figuring for air heat loss is terrifying, it comes out at 2/3 of the cost of heating the current house. The current house has a suspended timber ground floor with rock wool strung between the joists. Wind blows up inside all the walls, through sockets etc. I was quite surprised that the house isn't on a concrete slab, I just assumed it would be before it was built. It really hammers home that due to the size of my new place airtightness is the thing to work on. Your tariff details About your gas tariff Supplier E.ON (E.ON Energy Solutions Ltd) Tariff name E.ON Saver Plus Fixed 1 Year v2 Tariff type Fixed price Payment method Fixed monthly direct debit Unit rate 1.689p per kWh Standing charge 63.441p per day Tariff ends on 12 months from the date you switch Price guaranteed until 12 months from the date you switch Exit fees(if you cancel this tariff before the end date) £30 Discounts and additional charges Paperless billing discount: £5.00 a year Dual fuel discount: £10.00 a year Additional products or services included Not applicable About your electricity tariff Supplier E.ON (E.ON Energy Solutions Ltd) Tariff name E.ON Saver Plus Fixed 1 Year v2 Tariff type Fixed price Payment method Fixed monthly direct debit Unit rate 8.904p per kWh Standing charge 26.754p per day Tariff ends on 12 months from the date you switch Price guaranteed until 12 months from the date you switch Exit fees(if you cancel this tariff before the end date) £30 Discounts and additional charges Paperless billing discount: £5.00 a year Dual fuel discount: £10.00 a year