Which mortgage for refurbishing house?

Home_sweet_home

I have paid off the mortgage on my own home and 18 months ago inherited a flat and a house both in need of a major overhaul. I refurbished the flat with my own savings and have rented it out. Now I need to borrow £40K in order to do the same with the house. I’m not sure which mortgage I should be asking for re-mortgage or buy to let as neither really describe my situation. Should I borrow on the house which needs work on it as then I could offset the interest payments against future rent or could I borrow on the flat and still do this? I plan to repay the debt as quickly as possible over five years or less so am looking for a mortgage where the interest rates are calculated daily and there are no penalties for overpayments. Would be grateful for any comments or advice. I’m nearing retirement age so am hoping to repay this debt quickly and retire and live off of the rent on these two properties as I have no pension as I put it all into paying off my mortgage early.
Thanks for any help.

kingstreet

Raise a BTL remortgage on the flat you are renting out. The interest payment can be offset against the rental income for tax purposes. The rent will need to be around 125% of the monthly interest-only payments.

As the flat is already refurbed, it will be easier to remortgage this than it may be to raise a mortgage using the unrefurbed house as security.