Please talk to me about basement conversions

[Chiana]

DH and I are moving back to England next spring and although we haven’t even put our house here on the market yet, and won’t for a few months, we’re still window-shopping on RightMove, as one does. We saw one house that looked perfect from the photos and the floor plan, now since sold (of course), but it had a cellar converted into a basement, and no photos of the basement room on the listing. Are basement conversions particularly dark and/or prone to damp?

We were looking at a few other houses in the same area, and all of them had cellars. We weren't specifically looking for houses with cellars, they just happened to have them. t few of the houses didn’t have quite as much space as we were hoping for. DH piped up blithely, “Oh, well we can always convert the cellar into a basement ourselves if we decide we need more space.” As if it’s that easy. How much does a basement conversion cost, very very approximately? And how long does it take to do, and how hideous is the process of trying to live in the house whilst surrounded by builders?

I am deeply afeared of renovations. Our current house started out as a fixer-upper, and getting it shipshape whilst living there with a 2 year old and a small baby was hell on my nerves. We lived in a glorified building site for months on end. I’m not sure I could take that again, and I’ve already warned DH that our next house has to be move-in ready, unless he wants to move in as a single parent, LOL! So I am very dubious about the prospect of us doing a basement conversions, even though I realise that one rather runs out of space to expand in any other direction if you've already done a kitchen extension and a loft conversion in a terraced house.

Also, I wasn’t working when we were doing up our current house (well, I was definitely working, but not outside the home), and now I work, so my services as unpaid project manager and general troubleshooter will be unavailable. I'm thinking perhaps we should just bite the bullet and accept that we won't have quite as much space as we would like, but learn to live with it and not be precious about it.

So, has anybody on here either done a basement conversion or lived in a house with a converted basement? If so, I would be happy to receive any words of wisdom. After all, by the time we're looking seriously, there might be another house in the area where we're looking which also has a basement conversion. Thanks, all.

[TooMuchRain]

We have a cellar which could easily be converted into a living space because it would just need damp-proofing - but that would cost around £7000 so we just use it for storage instead . It didn't sound like a very complicated / long job though, just something that is not worth the cost unless you can really use the room.

[Chiana]

Thanks!

[Hong888]

Haven't done it but I designed them as a structural engineer previously.

If you need actual living space, then you will have to convert cellars properly, meaning, getting the right headroom by underpinning (expensive) and tanking, with quite complex construction.

cost/sqm found online:
No underpinning (750-1200)
Yes UP (2k-3k) - in most cases, it will be yes.

I think most big basement conversions you found in London are situated in expensive area to justify the cost. Besides, underpinning is very disruptive/noisy/messy kind of work and your neighbor will surely hate it.

[minipie]

I guess you are looking in London?

A proper basement conversion or dig out is a major piece of work involving enlarging the existing cellar, digging down to increase head height, underpinning to support the house and damp proofing of course. You would usually put a light well in the front and possibly the back too.

People use them for playrooms, guest rooms, au pair/live in nanny room, laundry and utility, gym, study, wine cellar... not all of these of course unless the house is huge!

Costs - I've read about 2000-2500 sq m, depending on the spec. Basement space isn't worth as much as above ground space. So property prices really need to be well above this for it to be worth it.

Hassle - yes I think it's pretty awful (not done it myself) though not as bad as say a kitchen project (as at least you keep your kitchen). It also costs more if you are living onsite during the work as they have to be slower and neater. Would living elsewhere for a few months be feasible?

End result - I have seen some lovely basement conversions. Yes they will be darker than above ground space, but with good light wells/light pipes and lighting they should still be nice spaces. Damp should be fine if you have got a proper damp proof course installed (this may be tricky in some low areas very close to the water table!)

My view is - buy something that you could happily live in without doing the basement - that way the basement is something you could do in the future if finances/house prices/energy levels permit , but it isn't something you feel forced to do at the outset.

[AngieM2]

Watching with interest. We've often toyed with the idea of doing ours. We have large double fronted Victorian so the current cellar is big, can stand up in it and has two good size windows/light wells. About 6 years ago we were quoted £25k just to tank/fit a pump, so not even giving us a habitable room really. I would guess a full conversion for us would be £35k+. Were in Worcestershire so its not a done thing like in London.

[clairewitchproject]

We have a basement conversion. The previous owners did it so I can't comment on cost. It is darker and cooler than the rest of the house, we run a dehumidifier periodically but it is perfectly livable, my teenaged son has his room down there and loves it. I suspect our particular basement was quite high - windows are abiut a foot above ground and ceilings are 7 or 8 feet ( as opposed to 12 feet in rest of house). So that might be significant in the feel of the rooms maybe.

[Chiana]

This is all fascinating. MNetters really do know everything! Thank you very much, everybody.

Yes, we will be looking in London.

[coraltoes]

I dug out and tanked a coal vault to turn into a large larder. It cost nearly £15k. That's from a vault that was maybe 1m tall before, so needed digging out, underpinning etc etc. it ain't cheap.

[TooMuchRain]

There was an article about this in the Guardian today - it listed the average London cost and it really wasn't cheap

[Chiana]

www.theguardian.com/lifeandstyle/2014/aug/18/basement-conversions-disputes-digging-iceberg-homes

Just found the article. Good God! Off to show it to DH and put paid to any "oh, we'll just convert the basement ourselves" blitheness. I can think of much better things to do with 250K than spending a year converting a basement, pissing off all the neighbours in the process.

[Quangle]

both my neighbours are doing it - I live in a small terraced house

I'm guessing they are spending about £200k and ending up with an extra underground room. The footprint of the houses is really small so it's not much extra space for the cost. Another neighbour has done it and she has an extra study and utility room - for the cost and upheaval I just don't get it.

[Binkybix]

We were quoted about £60k for a small basement which would not be enlarged and wouldn't need too much digging down, and is already tanked. Didn't include access, which would involve structural work too.

[Chiana]

Quangle, 200K seems like a big investment for an extra bedroom and maybe a wine cellar. Like wine stays undrunk in our house long enough to need a cellar to put it in! I kid, I kid, we are not huge drinkers. Although the thought of having workmen in for six months to a year and pissing off all the neighbours in the whole street would drive me to drink.

Where was I before I went off on my "I swear I'm not an alcoholic" tangent (and it's probably a bad sign when you have to tell people that)? Oh yes, 200K for an extra room. If your neighbours have 200K lying around, couldn't they just move to an already done-up house that's 200K more expensive than their current one, and save themselves all the building works aggro?

As for our case, I think DH and I may need to manage our expectations a little better. Most of the houses we've been looking at on Rightmove.co.uk in our price range have as much space as we need, just not as much space as we want. Time to separate out needs from wants, methinks. Oh, and a propos of nothing, London house prices are a frelling disgrace. I know, I know, first world problems.