Has that detail been done? I've read it must be at least 18mm OSB? And the sheer load becomes a big factor but I'm no S. E.

How would one comfortably fix the 100mm EPS? And ensure the batons are fixed along with the tiles and the subsequent solar regardless of method?

Posted By: ArtiglioFT are you finding that councils are pushing hard for people to go the pre app route? In my area it’s essentially a full application with a bit of discussion that turns it into an application they are happy with and so can pretty much rubber stamped when submitted as a planning application

No, not finding such a push, and yes what has to be submitted (in the rules, not just your area) is almost a full application, because they'll only advise on what's on paper - a preApp is nothing like a freewheeling discussion, and you're lucky if it includes an Officer site visit. And finally, they make clear that they're not bound by their own advice, once a full application is made!

So skip it, go straight to the full application, but draw it up and argue the case really well, go to town on the Design and Access statement, explanations, photos, precedents if applicable. Don't play the 'ask for more so they can cut it down' game - they can smell manipulation a mile off. Don't assume unspoken 'rules' - decide what makes sense and looks good and what you really want and go for that, no more no less. They will be relieved to see and respect that, unless you have a real B for a Planning Officer. It's easy to make your application stand out, professionally and enjoyably, from the clueless dross that Officers have to wade through.