Mortgage dilemma - move mortgage to new residential property?

Parisian

I am currently living in an apartment that I purchased for £322,500 - it is worth similar or a bit less now, and I have a £220,000 offset mortgage left on it which is out of fixed term (so I can change it at any time) and is pretty much fully offset with savings. 

I have recently inherited a house in full, worth approx £550,000. I am thinking to do some renovations with savings and move into the house. I will then aim to rent out my current flat. 

Is there the option of moving the mortgage from my flat to my house? What is that mortgage or process called? I can't quite figure it out, as it doesn't sound like porting as I already own the house, but I might be wrong. 

I know putting the flat on a buy to let mortgage is also an option, but I was thinking the interest will be higher than a standard residential or residential offset mortgage. 

I can't quite decide if it's better to keep the risk of a mortgage on a buy to let/rented out property, or just have/move the mortgage to my house and pay it off over time whilst I am living there. Any advice/tips would be very appreciated?! Or anything I might not have thought of as mortgage option?

Thank you!

kingstreet

Most lenders won't permit a port to a property you already own. You will need to ask yours.

You will be transferring the terms from the old mortgage to a new one and it sounds like you don't have a product to port if you are "out of fixed term" so I'm not sure what you are trying to achieve?

Typhoon2000

I think you are asking if you can get a mortgage on the house as you are fully offset on the flat so effectively can choose not to have a mortgage on the flat by paying it off? 

No you cant move a mortgage from one property to another, you have to apply for a new mortgage. You can port the rate/product but you are not in a fixed term product so you have nothing to port.