Knocking self contained annexe through to main house

[FlumpetCrumpet]

We are considering an offer on a house with that had an annexe built on to the side many moons ago and is self contained and a separate dwelling for council tax purposes. The house and the annexe are on the same title and they cannot be sold separately (this was a condition of the original planning approval for the annexe). We (a builder, this is not a DIY project on any level!) would want to knock through the adjoining internal walls and make it all one larger dwelling and eliminate the need to pay two lots of council tax in the process. Does anyone have an experience of having done this and have any advice? E.g. does it require planning permission? I assume that the council would reband it for council tax purposes if it was one dwelling? If it makes any difference the annexe has been used to house family members in the past and not for commercial, airbnb or other rental purposes. Thanks!

Highly unlikely to need pp. Generally the creation of a single unit from 2 is considered to be permitted development, but worth checking with the Council to see if there are any specific restrictions.

I’m sorry I don’t know much about it other than we have a bit of our house that was built as an annex but since the previous owners didn’t use it as such we don’t pay separate Council tax on it and they didn’t.
We use the annexe ‘kitchen’ as our utility room. It has a sink and fridge but no cooker - seem to remember the previous owners saying that if a cooker was put in it might then be considered as separate for council tax purposes.
We have doors through but it could easily be locked and blocked off. It has a separate ‘front door’ which we just use as another back door.
I guess what I’m trying to say is you might not have to knock down whole walls if you don’t want to! Could just incorporate the rooms into the main house but retain the flexibility for it to be an annexe in future.

Just a thought that if you were to purchase this property and it's over the stamp duty threshold you could get stamp duty relief if they are considered two separate dwellings. Not helpful to your council tax/wall reconfiguring query but might be helpful saving some ££

Thanks @Seeline I think that’s the conclusion I’m coming to from reading - worth spending the 50 quid writing to the council to confirm, but probably ok!

We definitely do want to knock through, speaking to the owners it made sense why they did it because of why they needed it but we have no need of a separate annexe and the house would work so much better as one home with bigger rooms.

It’s only 2 dwellings for council tax, it has a single title and cannot be subdivided

I thought it was having it's own kitchen that made it a separate dwelling for council tax purposes, rather than it being about walls/access? Couldn't swear to it, and hopefully someone here will know for certain, but dimly recall this from looking around a house that had turned the loft extension into a flat and it was the kitchenette that made the difference tax-wise - it was still part of the house otherwise.

You should also check whether there are two sets of utility meters as that would mean separate gas, electricity and water feeds.

It would be two dwellings for Stamp Duty regardless of the single title. If you knock it into one straight away you may not get the multiple dwellings relief but I suggest you check with a solicitor.

Thanks @Planttrees that's really useful information - just had a quick read up, worth making sure we explore that (you know, assuming we get anywhere with it, this is the 8th house we've offered on now )

We have just done this, converted an adjoining annex to incorporate it into the main house. Although we didn't have separate council tax we do have two boilers, kitchens etc. We removed a staircase and did other works. Personally I love two boilers, never any issues on the water pressure! In terms of building regs, the inspector came out before, during and after. Their main concern was fire exits. They needed to be sure there were adequate fire exits and detectors in the right places given we were removing an exit route. All in all it went very smoothly but you do need to get building regs involved, for a small fee it's peace of mind and you may be asked for paperwork for onward sale in the future.

oooooh I am thinking of doing this.
We have a large extension which incorporates part of the main house upstairs, (landing, large cupboard and family bathroom), with the remainder of it being a 2 floor, 2 room, kitchenette, bathroom annex.
You can enter via our utility room but it has its own outside entrance as well.

Its a single council tax and no questions were raised when we bought it. We are in Scotland.

I would like to incorporate the upstairs room of the annex into the main house, as we are a bedroom short. This could be done through the big cupboard.

Would then take away the stairs to make the downstairs of the annex bigger. With a view to it being a self contained granny flat /holiday let.

Have no idea if this would need planning, architects, engineers or whatever as I have never done anything this big.

Currently have a lodger in the downstairs annex room. She doesn't rent the whole. annex, just one room, although technically she has the kitchenette to herself as we don't use it and has her own entrance. We use the upstairs room for visitors and sleep overs.

I am a bit loath to ask the council in case they suddenly decide we are two dwellings for council tax!

“Unoccupied” annexes are exempt from council tax anyway