So, a quick update. I've been pondering roof hatches for a while... We had settled on two decent sized hatches at an early stage in the build. We were going to go with the normal large glass hatch, but after pricing them up and thinking about it, they always strike me as just another way for someone to break in... They are also pretty pricey for two large hatches. So, with that in mind we then thought about not bothering, but (as Wifetec rightly says) if we don't do it now, it'll never happen! I have taken a punt and an going to make two solid insulated hatches. We need ventilation, we need easy roof access, but we don't need light (especially 40 deg Aussie light!). We have settled on 700mm wide, and 1000mm long. We will have one above the bed and one above the kitchen. Yesterday I fabricated the two frames out of some light 45 x45 x 2 RHS.