[stephen_g]

Yeah, that's it. Luckily it's not actually too hard to remove the ceiling tiles - they're not standard size grid but are drop-in, so nothing has to be cut to remove them and we can have new ceiling tiles made with a non-asbestos fibreboard with an insulation panel glued to the back of it. We'll probably end up removing about a fifth of the tiles in strategic locations for access and ceiling mounted things, because the disposal cost is so high to do all of them. Ideally we could get it all gone but as you said, it's just finding the cost/benefit balance.