Thanks again. Should there be substrate or soil in the bottom of the cold frame? I guess they will need a little house in there too? What is the hottest it can be there for them to be ok? J x

A cold frame is used as a warming spot within the out door enclosure, for cooler days and cool mornings, just pop it straight onto the enclosure ground ( soil) with a hole cut in one end ( if it's wood) so they can come and go as they please. You can open the top of it gets too hot ( above 32c) . There's no need for a house in it.

This is my babies enclosure with wooden cold frame on the left of the picture, the lid is open , it must have been hot, there is a hole cut out at the end so they can come and go as they please. Ignore the news paper in it, it doesn't need anything in it.
http://i1270.photobucket.com/albums/...ps5439n5oq.jpg

Looks lovely and all that sunshine too.

Interesting you have to borrow some space above for your washing!

I think a good idea is to make sure that there is some proper deep shade inside the coldframe somewhere. You might not be around to open the lid. Something like an upturned plastic washing up bowl with a hole for entry and exit. It can still get very warm in there but there won't be any direct convection from the sun's rays.

Soil in the bottom of the coldframe is good but they won't always dig.

The way my outdoor enclosures work there is always a wire mesh cover. This is because of magpies and cats. Without the mesh cover, magpies will attack small tortoises and cats like somewhere warm such as a coldframe. Younger cats will play with a smaller tortoise and can cause damage. But keepers in places where there are no magpies or seagulls often don't need mesh covers.

All my outside enclosures have mesh lids too - as Jonathan says, it keeps away birds of prey and cats and stops cats using the soil as a litter tray!!

loving the enclosure pictures !

Wondering about seagulls in Scotland ? Are there many Jonathan. They attack buzzards here its very strange when they do as the noise is terrific and the buzzards just soar, CB