Coldframe/greenhouse

[tootles]

Huge scarey winds have finally finished off my greenhouse. I had hoped that it would last for more than one season, but never mind.
I am now torn as to what to replace it with. I now realise that it will only be used for bringing on seeds early, I don't need to keep anything in it over the summer months. Luckily all greenhouse plants quite like the weather here outside.
I am wondering whether a coldframe might serve just as well?
How effective are they for starting seeds when it is still quite nippy outside?? Do they give adequate protection from frosts??
Is height off the ground a really important factor??
And, is it really possible to keep it warm overnight with a few tealights (read that one somewhere else today)??

Does anyone else use one as their primary 'undercover operation' and can you advise??

[OverWyreGrower]

We will be dismantling our lovely, huge, wooden, rotten greenhouse in a month or so, and plan to replace with a polytunnel, which means we can get a bigger one for less money.

Mind you, seeing as you are in France, you might be able to get away with a couple of coldframes? You could always fleece them up if it gets a bit nippy?

I'm sure I read about a 'hot box' somewhere, but honestly can't remember where!