Converting a conservatory to a 'fixed' room

[ScoobyDoesnt]

Looking for some help / advice please!

I've viewed a house I really like with a conservatory on the back. Left hand wall is full brick, front and right hand side is dwarf wall with glass above, and a double french door on the front - plus what looks like a plastic (vs glass roof). Size is roughly 11 ft deep by 16ft wide. Roof is a simple slanting one from the house down to the front of the conservatory (i.e. not hipped at all).

It has central heating (2 radiators) and electric plug sockets.

I would want to change this to a proper room which I would want to move kitchen into to make a kitchen / diner space - i.e. with more brick, bi folds, windows, and a proper tiled roof maybe with velux.

Two questions:

1. Is this likely to need planning even if I'm not changing the footprint, pitch of roof etc.? I understand there is planning for the conservatory from a few years back, although have not investigated this yet. Not in a conservation area, house not listed. No party wall issues as both side walls are within the fenced boundary.
2. If you've done this - roughly what is the cost of just changing it to a proper room? (I can factor in kitchen cost, electrics, plumbing etc. myself). I'm making an assumption the foundations may already be ok if they're carrying the weight of brick and glass already.

I've just no idea with building costs currently whether this is a £10k or £50k job!

I don't like the conservatory as it is, but the opportunity to change it and have a large kitchen space facing on the garden makes it an attractive option as the house is about £40-50k under my max budget.

Thank you

My neighbours have just done this. Didn’t need planning and it cost 20k

OP You might not need planning permission but you'll almost certainly need building regulations approval.

You probably know all of what's described on these webpages, but just in case:
https://perfectwirral.co.uk/how-to-convert-a-conservatory-into-a-functional-living-space-or-kitchen-expert-tips-and-ideas

https://www.conservatoryland.com/frequently-asked-questions/building-regulations/

We put a roof on ours but didn't change any walls. It's a very big room and cost us about £14k but that was back in 2020. We had to get building regs but that was all. Definitely worth it.

@nameXname - thank you, those links are really useful. I had thought about building regs, but forgot to add into my post.

@Pringlebeak that's so helpful, thank you - I would need to change some walls, but that's good to get an idea. I just had no clue where to start!

Actually (derp) I've just remembered my mum had it done a few weeks ago on a smaller conservatory and that came to £10k.

If the conservatory needed PP (rather than building regs) then the extension will almost certainly need it.

We've got a wood conservatory that came with the house and we have had builders out to quote for making it into a proper extension. It has electricity etc but quotes came out between £40 and £50k. They need to replace the base, dig down further and start from scratch basically.

Be aware that putting a solid roof on will cut down the light in any room which currently accesses the conservatory. Our previous neighbours did what you describe, it made the dining room which had the French windows into the conservatory as the natural light source into a a very dark and essentially windowless room. It took them ages to sell the house, as people didn’t want the dark middle room.

We did exactly this last year and all in it was just under £20k. As PP say, no planning needed just bldgs regs

I put a proper roof on our conservatory but tbh I wish we'd started again from scratch with a proper extension. Heat retention is still abysmal.

Thank you. I've been trying to search for the alleged permission on the local council portal, but can't find anything. So may it was permitted development and the vendors are confused. They've only been there 4 years, and the conservatory is definitely older than that.

@Patienceinshortsupply thank you, yes there's always that danger I guess. The house as it is is still lovely, great location, nice garden and so on - just always wanted a big kitchen!

@Allthegoodnamesarechosen thank you, the conservatory / garden are south west facing so I'd be hopeful that with velux, light would be ok. The room it's off is one room, with a large front window and french doors to the conservatory.

@Baconsarnie great - that's good to know, thanks!

@Doitrightnow also good to know, and definitely worth thinking about if it's a scrap and start again job!

Lots to think about, thank you!

I don't know the details but think there's something in the regs for conservatories to do with having an external type door into it from the house and if it doesn't have that it wouldn't meet regs (??). Possibly something to do with EPC rating as they generally wouldn't be well insulated. It's worth checking with the vendor or the council if there was building regs sign off - there are lots of conservatories which have never had sign off which become an issue for the new owner if they want to make any changes.

I’ve been quoting for this exact job recently. I can’t afford a proper extension.

To have the frames replaced, solid rubber roof put on with a roof lantern (with a steel support) and new windows. The prices have come in ranging from £8-£18k!

It depends how bothered you are about building control and how likely you are to sell it. I’m sure lots of people will be disgusted at this but none of my house has building sign off (thanks to being hundreds of years old!) and has sold numerous times without issue.

Thats not including new floors, heating etc.

We did this 2 years ago and I’m afraid it was £75k plus flooring and kitchen. South East. Love it though!!

Are you planning on knocking through a wall into where the conservatory is now? If so there might be regs involved as you can't lose thermal efficiency.

We did this. We moved into a house with an old draughty conservatory, plastic roof etc. It did have a radiator but it was freezing. We had a roof put on and a ceiling fitted, plastered and painted. A few windows were replaced. Just had a new laminated flooring and blinds fitted. The one wall is wallpapered. No planning needed as footprint stayed same. It's gorgeous and my favourite room. Cost was approx £14k.

Building regs changed fairly recently to include much thicker insulation in the walls, so it is unlikely that the full wall already built will comply. I also wouldnt assume that the foundations are adequate, they may be poorly insulated plus two walls of block and bricks weigh far more than a single skin of half brick and windows.
A simple conversion with new roof is easy enough (although a full replacement roof can be costly - we did this in our last house) but if you want to move your kitchen into the space you will definitely have more work and building regs to adhere to, including drainage and extraction etc to think about.

Thanks again all.

@kitchenhelprequired there’s double glazed french doors from the lounge into the conservatory, so hopefully that’s sufficient. Will definitely check re building regs, I’m going to ask today as I’m considering an offer.

@Moll2020 thank you, that’s good to know!

@JollyMollyPolly I did try and look at the wall, and from the outside it does look like it’s thick enough to be double skinned, but definitely need to think about that. Foundations are a bit more tricky - but I will factor in that they may need redoing. In a previous house years ago we added an extension on to the top of an existing single story, and they had to add to the foundations, but did it without having to dig it all up from memory. Building regs of course may have changed now. There’s plumbing and drainage available as the other side of the brick wall is a utility room with a washing machine in.

Lots to think about! The house is fine as it, but I’d just like to replace the conservatory as it’s looking a bit knackered and just have this thing about a bigger kitchen that is out onto the garden!

This is the person who was house hunting saying she wanted a house with no major works to be done!

Following the thread with interest as we have a classic conservatory with one half wall and one full glass with the end shaped bit also glass.

id love to make it into a normal room as it’s freezing in winter and boiling in summer.

stupid question but what kind of company would do this work? A building firm?

Conservatory or double glazing companies will do it.

We looked at this... it came down to the angle with our neighbours property. While our conservatory was within regulations, a proper extension would have to be quite a bit smaller so as not to block the neighbours light.

However the maximum was 3m so your conservatory might be within that already