Installing a basement
  • Anyone done this?
  • I had quote for it
  • U live in a flat in Dubai, I thought
  • combination of neighbour below and sandy subsoils makes it tricky 4 u.

Do you mean digging one out or converting an existing space into a more usable one?

The former is very expensive. If you have room for a rear and side or loft extension - do that first instead. 


  • Cheese, the former.
  • Yeh was thinking rear.
  • Just burrow outwards into the garden, yeh.

He means neither.  it's a thing that he thinks makes him sound like a player (like boasting that his shitty bean2cup uses lavazza supermarket beans).

  • Someone's not dealing with furlough very well today. 

A rear will require digging deeper foundations and annoying party wall notifications too if you are in UK and have neighbours close by. Probably far cheaper than digging out for a proper basement conversion though.  

Do you actually have any clue how to build a house Dolla?

You've been going on about it for years.

  • Yes I figured extending out under the garden would cost less. 
  • No I don’t have a clue.
  • But I know what I like and the war chest is primed. 

If this was a real question, I've got the info has my mate has done this and I have all his costing info. We had 3 quotes. There's a price per sq foot for dig from scratch, renovate existing space and then fit out. £280-420k plus vat demanding on footprint and fit out standard

Little Dollah needs one to hide his Love Dolls in when his Mum calls round to clean for him.

Remember it’s also no longer covered my permitted development in most of London and your neighbours will all object to your planning application.

My neighbour dug out a basement years ago in London and it went on forever including pneumatic drilling at weekends.

Neighbours objecting doesn’t mean shit. It’s either permitted or it’s not.

Robbie Williams wanted to dig out some massive basement in his north London house. His neighbour objected. One Jimmy Page. Legals ensued.

Quite funny, not sure how it ended up.

I read that post without seeing the name and knew it was chambo. 

I just looked it up. £2000+vat per sq m for the shell (so inverted swimming pool - keeps water out, membrane, tanking and pump). 


Fitout £1200-£2200+ vat per sq foot. Depends on spec.  £1200 is fairly basic. 

Doesn't include design and planning fees (about £15k) and CAR-non negligence extension (£5k), skips and parking suspension (that's very spenny and depends on your Local Authority (some don't allow double bay suspension so takes longer and you only have the small skip).  You need space for a portaloo (usually another parking bay). 


If your road has 1 or 2 hrs parking controls you're in luck. If it's 4+hrs it costs a lot more. 

Housing prices need to be over £800/sq foot to make it viable. But still, the sq footage goes up but the scale of your home doesn't. I prefer fewer large rooms than lots of small ones. 


You need to spec finished room ceiling height of minimum 2.8m. 3m is best. Otherwise it's gonna look dingy. 


Why does one need a basement, if one lives in a cardboard box in the Desert?

We have planning permission to do a basement in our house (didn’t do it in the end) and the quotes we got were nowhere near those prices jelly (and this is for central london). Although with stamp duty even at those prices it’s cheaper than moving somewhere else. 

I thought Robbie lived in kensington. Iirc he lost in the end? 

That wasn't the cheapest, but it was the most reputable and it's a fixed price. I expect there was a better deal to be done on the fitout. They also quoted for extra 2.5m X 3.2m loft pod at £40k, which should have been £26k, but didn't pursue as prefers to get a bigger house/garden than adding extra floor to what we have. And this *is* naice London, fankewevehrymooch.

I think Robbie and Jimmy settles but Jimmy’s case was helped by his place being grade I listed.

Jelly, those prices seem mental, but I have no idea. Was this one of those huge outfits that does million quid plus basements in Kensington, or a small local firm, with 2/3 builders.

My friends father is a a self employed plumber, does very well. He had one done by a local firm, and very nice it is to, whilst I am sure he makes a very nice living, doubt he can afford 300k plus for one.

A lot of loft contractors are doing basements now on the cheap. Some dude in North London asked a plumbing contractor who obliged. The house collapsed.  There's another on in SW London that's condemned currently. Think they need to pour in 200 cubic metres of concrete to remedy it. 

But average terraced house has a floor plan (for full footprint of about 90sq m). Assume you can negotiate to 3000 sq m, so adding vat and other prelims, you end up at about £350k for extra bedroom, bathroom, utility and large living area. 

Fair does, in my neck of the woods in south west London, there are a few very reputable ones, recommended by reputable agents, surveyors and architechts , a quick look suggest they are small.My friends father lives in what is far from the most salubrious area/street, but it is very nice. No way he can afford the numbers you suggest.

I would definitely invest a multi 6 figure dolla sum to develop a property I only own if it's convenient for me to own it to a medieval bunch of fuckits with an economy wholly dependent on an increasingly less valuable resource. 

Getting an extra 2,910 square meters is a hell of a basement given that that’s pushing 30,000 square feet...

Ah I just saw you were pricing in sqm not sqft. That makes more sense. 

basically basement will usually makes sense in london as you are paying a hell of a lot more per sqft to buy more space plus you have to pay ludicrous stamp duty on the entire property when you move which if you’ve already paid one insane set of duty feels like chucking good money after bad. 

I think you need to able to get a lot of light into it preferably with a proper terrace at that level. If not and its just a cellar effectively, then I wouldn't pay full whack per sq ft for it.

  • Cheers for the detail Jelly. 
  • No need for a pool. 
  • Pointless in the UK and I'm good for pools let me tell you. 
  • Not sure I ever want to see another. 
  • The basement would likely be a simple space for gym and den.
  • As AWU says, natural light would be key. 
  • Access and local house prices no issue. 
  • My gut says if you can get the job done for day half the price of a decent 2-bed BTL, you're winning. 
  • No stamp as everyone says. 
  • Do it well and you get it back if you sell. 

Inverted pool. 

A pool is a hole in the ground to contain water. 

This is a hole in the ground that needs to be water tight to keep water out. 

Well. Quite. Wouldn’t have happened in Edwardian times. 

Unless you have so many kids they are flowing out of the bedrooms a basement will not improve your life - you can only occupy one bit of space at a time .  You will put up with a year of disruption and misery  - feel more than usually happy for a month or two when it finished then revert back to your mean level of satisfaction.  Waste of time and  money

play room/second living room, utility room, gym, spare bedroom and ensuite, CLIMATE CONTROLLED WINE CELLAR

none of these things are worth the hassle Jelly unless you are genuinely short of space because of a large family.

I'm slightly unclear about something here hyoobert - which house are you  proposing for the new basement?

I don't think that you can mean the 'dream gaffe' that you bought in Solihull as at the time of purchase you were quite clear on its extensive size, so I can't see why you would want that extending (and if you did them sure you would just go sideways out into the extensive grounds that you were also kind enough to dwell on in some detail).

But also I don't think that you can mean the Clifton townhouse that you acquired as you mentioned that access and local house prices would not be an issue.

Have you gone and acquired some other house without telling us you wicked boy?  That would be so like you!

But seriously, I am worried about you.  Supervising this new basement construction as well as the new build that you are talking about, in addition to running your 2 existing UK homes, let alone the one in America and the one in the Balearics is going to be a huge task - even for a man of your abilities.  Just be careful and look after yourself is all I am saying.


Strutter cannot be the one in Clifton as that was four story anyway, who needs a fifth...

That is just little people talk and you should be ashamed of yourself.


  • I once bid on a choice gaff where the geeza had dug himself a wine cellar complete with glass trapdoor and spiral ladder.
  • It was one of the things that decided me against it.
  • He had also made the mistake of going too small. 

for me it was the extra playroom/living room.

We currently have the standard config of 2 reception rooms (but actually a living room and dining room with an open arch between, so not actually 2 rooms).  We've got kids and we live in London.  If you live in the arse end, you can expect your kids to fuck off for drugs and clubs aged 20 and come home for laundry and food at the occasional weekend.


So a second living space will make the next 20years bearable.  

See, this is what I mean about having too much on your plate.

In your rush to tell us about the glass trapdoor (killer anecdote by the way) you neglected to mention which house you are proposing to do this basement extension on hyoobert.

A second reception space for children is probably the best justification for one if you can't go back or sideways as many can't in London. The other stuff, gym, cinema etc is nice to have but not at the cost of doing a basement. Guest/ au pair bedroom as well but you'd definitely want a terrace off that or it would be a bit grim.

I haven't, but Mr Goldswain and Miss Hale did.

Mr E Goldswain and Miss J Hale v (1) Beltec Limited (trading as BCS Consulting) (2) AIMS Plumbing and Building Services Limited [2015] EWHC 556 (TCC).

Despite being pretty much blameless they are royally fucked forever.

Friends did this when they had the place built. Over the period of ownership, they had to move out for a total of 18 months while (a) the membrane was replaced, involving lifting the entire house onto an air filled cushion using hydraulics and then (b) when the pump failed. ALl in order to get a windowless library, windowless utility and a dungeon like games / spare bedroom and windowless bathroom. They moved house in the end and the new people were flooded within a week.

PS Jelly - I bought a lavazza foamer and it's way better than the steam wand on the b2c and way, way better than shaking the bonne maman jar

I had one of those sorts of things for a while when I was between coffee machines (a mate married late, and they each had a nespresso full montie machine).  It's ok, but you don't get the same density of foam as you do with a proper machine.  I used it more for cheat cullinary foam (apple juice, on cold froth mode and spoon off the top 2cm of foam each time).

this foams so dense you could walk on it. it's marvellous. really quite excellent.

(& next door also had a cinema room downstairs adn the new idiots immediately removed the specially designed seats that the insurers had made and put back in. What that basement has cost insurers makes my mind boggle, largely as am doing own household insurance renewal today)

  • The basement isn't a slam dunk but that's fine.
  • The other option is to build a new house from scratch. 
  • To be honest that's more tempting. 
  • I've surfed enough architecture to know I'd design it well. 
  • Execution wouldn't be cheap but it wouldn't be exhortbitant either. 

Shall we all chip in to buy Little Dollah a new Dolls House to play with, complete with underground bunker?