Goggs

I have a company that appears to be well known, lots of Build It awards etc., that have designed a wooden stair for my SIPS build. They cannot provide structural calculations which is OK as I have a structural engineer who is working on that. They cannot provide material strengths of the oak they are supplying. My engineer has specced D30 solid oak but the manufacturer is saying they never use that spec as it is unnecessary, however, cannot provide a me a spec other than it is knot free and Grade 1? I won't mention their name at the moment but they have 17 years trading in the UK, stairs are built in a factory in Poland, they have been mentioned in several articles in build It magazine for their designs. Does anybody have experience of stair building in Scotland and exactly what needs to be supplied to get the building warrant for the design? This is different in England where the rules are a bit more relaxed apparently.

Thanks for your comments. Spoke to Buildstore about a mortgage but because I am self employed and in my 60's, it was getting very complicated. Bridging loan seemed the way to go. However, I can see us having to sell up first. The plus point is that we can do a lot of the ground works and foundations our selves, SIPS house so goes up pretty quick.

We own our current house which is valued at 600k and we have a 100k mortgage. We plan to self build and have the land. Our budget is 450k. Our options as I see it are; sell the house and live on site in a residential "lodge" or rent a house nearby (rental market is not good in the area). The other option is to take a bridging loan for the 9 month build time and pay it off when we sell our current house. I want to be mortgage free at the end of the build. Has anybody got any experience of bridging loan agents/banks that they can share?

Sounds good. It is SIPS ECO that have quoted the thicker EPS panels. What was your experience with SIPSECO from a service delivery perspective?

Thanks and glad to be here. From what I gather PUR has a better thermal performance than EPS resulting in a thinner, lighter panel. I can imagine that PUR panels are more difficult to manufacture compared to EPS. As long as the thermal values are comparable, thicker panels are not a bad thing, just need to take into account transportation and handling.

Just sent out my architect drawings to 4 well known SIPS manufacturers for quotes. Its a 340m2 house, barn type structure. I have 2 quotes back, similar pricing but quoting very different panels. One has quoted 150mm thick panels for the walls and roof but they are polyurethane sandwich with a U of 0.024 w/m2 which seems incredibly low. The other is 194mm for the walls and 219mm for the roof but polystyrene sandwich with U of 0.18 w/m2 and 0.15 w/m2 respectively. The U value for the polyurethane SIP seems incredibly low and it is the thinner panel. Anybody got any experience of polyurethane vs polystyrene panels?