Multi unit freehold block

Property Investment

I have an old Victorian house which has been converted to 4 self contained apartments each with their own boiler, bathroom, kitchen, bedrooms, etc. The only shared area is the entrance hall and communal parking to the rear. The water supply is also shared.

I am about to re-mortgage and was surprised to see that rates for MUFB's are almost double that for an HMO, which is odd as there seems to be less risk - tenants stay longer as well!

I had a thought - what if I split the freehold and register each flat individually and then re-mortgage each one individually. I would get way better % rates.

Does anyone know how I would do that? i.e. how do I split the freehold and register each flat? I could then sell each flat if I wanted...

I think I would need to setup a Ltd company for maintenance, repairs, gardening of communal areas, shared water bill, etc but I'm not sure how to split the freehold..the property is mortgaged.

Can anyone offer any help of advice please?