top up mortgage

Just wondering how a top up mortgage works for the future...
i.e. How long do you have to wait on your first mortgage as a first time buyer?

A year, two or more?

I assume the house would have to go up in value by the amount required and the LTV ratio would have to stay the same?

How do you prove the new value? Would you need a valuation or the price of a new house in the same estate?

What criteria would the lender apply? i.e what would improve your chances?

Any information appreciated.

It depends on how quickly in value your house goes up by. Banks will generally lend at least 85% so if the value if your house goes up quickly then you should be able to release equity on this providing they feel you can afford the extra payment. Generally you need a valuation but sometimes they don't bother asking if they there is a huge gap between what you have owed and the value of houses in your area.