Humpty Dumpty

I also triple glazed and some of my windows are huge. I went with a half and half approach generally and placed the window partially on the insulated form work and partially on the concrete for smaller windows. However with larger windows I decided to build a Newton block plint directly off the floor then insulated them to the exterior.

A trusty warrior hoist 500kg to do all the lifting best 250 quid I ever spent

I have only built with velox but sismo was my other preference. Never built before. 1st time. Anyone with half decent carpentry skills can do it.

Sismo? Basically it’s an insulated metal cage which come in large format blocks and you just wire clip the cages together. It has to be used with a proprietary scaffold that clips to the cage internally to the build and holds it plumb for concrete pour..... whereas velox I built 3 storeys no scaffold (tut tut... I know but it was safe enough) , just working off the internal floor slabs with my trusty little tower and a big ladder. It can be done but with lots and lots of care.....

That’s the spirit

Bracing

No worries. If it helps all good. Velox does have a tendency to warp slightly in wet weather can become a bit banana shaped which makes alignment a bit harder. So the slower the build the more the difficulty. Don’t get me wrong. Warts and all overall all said and done I do like it and wouldn’t say don’t use it. also had a few boards split through the centre during pour but noticed them and managed to brace them in time. You learn as as you go along and will make mistakes... trouble and strife shared can make it a smoother process for others. gables are difficult though and really do need lots of bracing. I tended to brace using 4x4s every 2 meters and sometimes less.... you can also insert additional timbers between the WSD boards and the bracing screw lock the walls plumb..... takes some trial and error to get it right

No was ICF from the off. Off the traditional ICF’s and I went through the lot of them my overall preference was nudura and quadlock. Of the two I think quadlock win.

Render is easy enough if you’ve got the right clobber. I went here for my machine https://www.plasterers1stopshop.co.uk/ couldnt recommend them highly enough great bunch and they’re train you to spay when you collect the machine

Blow out bottom of a 2.5 Mtr wall through which I lost several tons of concrete.... happened twice on the same pour..... hell of a mess and clean up job while you have trucks backing up with wet concrete. Small off cut panel = weakness which needs shoring up very well to prevent.

Whatever system you go with decide on the system first before getting planning approval. Not so much of an issue with sismo and a completely freestyle build using hired shuttering, but if you go with velox do your drawing & dims to the build system, increments of 500mm/250mm height and 1/2/1.5 meters lengthways. Minimises wastage and cutting which all makes for a quicker cheaper build. I didn’t do that and wasted material because of it. Same goes for position and sizing of windows doors etc......

What can go wrong

It was a toss up. Was a solo self build. Something to keep me out of mischief at weekends. I though velox was easier but don’t think it turned out that way. Had Sismo quoted to include assembly and pour (they do that option as do velox) inc materials and build from memory Simso was circa. 65/70k ..... all in of which assembly was circa 25/30k and you get 3D scale drawings etc.... velox quoted 50k to assemble and build and mats cost me circa 70k. There’s a trade off as I still feel Sismo isn’t as good.... terms of insulation. I also thought about using metal shuttering laid to insulation slabs to exterior pre plugged to affix to concrete prior to pour and think that would have been as quick as Simso and cheaper than both build systems. The figures above don’t include concrete