I apologise, I should've mentioned that I am not in the US. Since most of the members here know me from the other sites I didn't think to mention it.
Our voltage is similar to the UK, yes. As for building requirements, as I mentioned before it is a grey area and differs from town to town, especially the enforcement of said requirements! We do plan to stick to whatever requirements is set in our area though.
The roofs sheets are about 0.5 inch thick and made from fibre cement, I don't know if you are familiar with it? And it is quite secure, we checked it out already

We do not have hurricane winds in our part of the world, but being so close to the sea we do have a fair amount of wind and it hasn't caused any problems yet.
Well, I'm sorry you feel that way. I have put this thread in the "Off topic" section as my intention was simply to share our project with whoever is interested in following our story, comment, offer advice and have the occasional laugh or cry with us. I am aware that the way we do things here are different from the way you do things there. If you are interested in seeing how we do things here though, stick around. There's more to come...
