Converting two flats back into one house

[itellyouwhat]

Does anyone have any experience of the above? We are looking into how we would go about it. We own one of the flats in a Victorian 3 storey terrace (and live there) and there may be an opportunity to buy the 2nd so we would like to convert back into one house. I understand we'd need planning permission. But what are the legal costs involved and how lengthy is the process? Would we buy the flat first so we own two deeds then apply to convert afterwards? We would then need to put in an internal stair case from ground level to basement. Wondering how much might be? Any advice gratefully received!

We did exactly this, you don't need planning permission but apply to the council for a certificate for change of use. We had to submit floor plans to show how we would reconfigure the property. I did these myself as it was a fairly straightforward merger that involved removing one partition wall. The whole process from application to being granted took around 6 weeks. I think it's highly unlikely the council would refuse. We owned the lower flat (2 floors) and bought the upper flat (2 floors) and our mortgage lender would only allow us to complete when we had the paperwork in order. We also had to deal with mortgage lenders being weird about it, and wanting proof that we would convert it back into one property, and weren't buying it to let the second. In the end we used a broker who was brilliant.
We didn't have to put in a new staircase but had to rebuild the existing staircase ( when we took the wall out there was no handrail on the stairs), which cost us about 2k. We still haven't figured out how to merge the gas and electrics (2 meters), but now have a huge and wonderful 6 bed home in London that we could never have afforded any other way. We removed the duplicate kitchen ourselves, and have gradually done it up. It's a very cost effective way to gain more space, no moving costs or hassle!

We also did this to a Victorian terrace. No planning needed. The council is simply involved in building control and change of use for council tax. The finance can be tricky but we manage to put all the mortgage on one flat and buy the other outright. We did it in a gentrifying area and made a fortune...

Westminster have a blanket policy of refusing this Dort of thing, I believe. Camden too? So take advice before you do anything - write to planners

Thanks for your replies. I'll speak to our council first.

Completely off the track but would that mean you'd have two leaseholds stuck together? Guessing/presuming flats can't be freehold. What are the leasehold agreements? Are they the same? How many years left on the leases? who actually owns the building? Would they need to agree too? :)

A friend of mine did this. I believe she didn't have to pay VAT on the costs of converting it back to one dwelling. Worth checking.

we jointly own the freehold with the other flat so if buying and converting back to a house we would apply to change the deeds into one. Interesting about avoiding VAT costs of converting :-)