sell or rent out?

[Celibin]

we have one bed flat that is too small for us to live in as we need 2 beds. Major work is planned for the outside which will mean we will have to extend mortgage (which only has 2 years to run) inside needs a bit of dglazing and heating replaced. we currently rent .Should we just sell so we can buy a bigger place ?

If I understand right, you are already letting out this flat?
I would say it depends on many things: is it in London or in a place where the market is slow?
It looks like the coming months are going to be/are a good time to buy but not such a good time to sell. I am tempted to say that if you can afford to buy elsewhere without having to sell and are prepared to put up with the hassle renting it out might give, I would rent it out.
Obviously you need to be financially secure enough to fork out any money necessary to fix broken things in the property you rent out.