If you can afford the initial outlay, roof insulation is an absolute must for all houses. In our last house, we had the standard fibreglass batts installed. They worked well, but I often felt guilty about using such a horrid, toxic substance. On one occasion when I was working up in the roof, I had troubles breathing for days afterwards and my skin was terribly itchy.

In our new house, we opted for recycled cellulose fibre, it was more expensive, but it has far better insulation quality than normal batts; therefore, over time there will be substantial cost savings - it's also a green option.

Recycled cellulose fibre comes in sheets, but in roof applications, it's usually sprayed on using compressed air.

The insulation is treated to make it fire retardant - so fire retardant in fact that if you scoop up a handful and apply a blowtorch to it, it won't flame, just go black and your hand won't be burned. Of course, this is something you should have the sales rep demonstrate :).

This fire retardant behavior gives recycled cellulose fibre the added value of helping to protect your house in case of a roof fire - it can slow the fire down. In most cases, as in ours, the flame retardant used is environmentally friendly.

The other benefit of recycled cellulose fibre is that it's treated to be a vermin repellent - no more mice and bugs in your roof!

We'd welcome any other green insulation tips you might have; please add them below.