Mortgage query..

I've a query about mortgages if anyone can help!

I'm a nordy who recently move to big dubs to take up a new job. I own a house in Belfast and currently renting it out as if I sold I wouldn't come close to a deposit for a house down here.

So my query is, if I was to sell my house in the north, could I get away as being a 'first time buyer' here, and hence only need the 10% deposit, instead of the 20% needed for trading up?

Either way, it'll still take a few years I reckon before I can afford somewhere, but would be nice to know. Cheers!