Small extention - Is this quote about right - first one and waiting for another couple

[202617thjan]

So for context in London / small extension (we're going out by less than 2m). First quote in of £84k ish (inc VAT) here is the breakdown - does this seem about right? High / Low. Thank you.

Sorry it's quite a long quote!

Skips £5,000.00
Carpark/permits £0.00
Structural heavy lifters £500.00
Health and safety £375.00
Insurance £375.00
Access towers £800.00
Protection £870.00
Prints allowance £150.00
Temporary support design £550.00
"Demolitions, excavations and temporary works
"
General demolition £1,620.00
Removal of existing hard stand in the shed £240.00
Excavation for new floor buildup specified by SE in new extension area £702.00
Kitchen demolition £540.00
Chimney to remove £610.00
Floors and ceiling removal in the GF £870.00
"Walls removal in the GF
" £2,553.60
Roof removal from existing brick shed/extension £510.00
Footing excavation rear extension £1,170.00
Footing excavation under internal new block wall £221.00
Temporarily support PC sum £600.00
Electric temporarily supply and insulation £470.00
Gas cup off and unnecessary pipes removal. £350.00
"Structure & Envelope
"
Mass concrete footing
Formwork £802.50
Concrete fill - 600/600mm £1,444.50
Padstones £840.00
"250x215x10mm thick steel
plate" £100.00
"Structural steel specified by SE Ancore, including fittings, fixings,
shop and site installation" £4,554.00
Intumescent paint £700.00
Potential repairing works to first floor following steel work £530.00
£0.00
"Walls & DPC - extension
"
Bricks to match existing £3,090.00
Blockwork £1,650.00
Engineering bricks £440.00
DPC £17.50
Air bricks £17.00
Cavity containing £370.00
90mm Eurowall plus £280.00
Catnic installation £200.00

"GF floor buildup (extension)
"
Raised up floor in back section to make level with rest of the kitchen £730.00
C24 150 x 50 mm in extension area on hangers £517.50
Concrete Blinding - 100mm - extension area only £337.50
DPM £175.00
Insulation - Kingspan K103 - 100mm - whole floor in the kitchen £1,312.50
Polythene Vapour control Layer £137.50
Plywood WBP 22mm - whole floor in the kitchen/toilet £1,750.00

"Roof
"
ROOF STRUCTURE - Flat roof extension following detailas from drg.no 19FRBR41
Roof joist 50 x 150 £450.00
18mm wbp ply dec £283.50
150mm powerdeck F150mm by recticel £220.00
18mm wbp ply dec £283.50
Single ply membrane £825.00
Gutter and downpipe £420.00
Fascia £180.00
Roof above bay windows
New gutter and downpipe to the existing roof £420.00

"Plasterboarding/new studwalls
"
Ceiling GF - Plasterboard - 12.5mm £775.00
New stud wall to the GF toilet £630.00
Plasterboarding in the GF extension dab on the walls £429.00

"New mdf skirtings, architraves- ready for decoration
"
MDF Skirting £480.00

"Skim and Decoration
"
£0.00
Skim - 3mm £1,380.00
Walls and ceiling painting £2,384.20
woodwork paint £495.00

"M&E
"
"Electric points
" £2,550.00
Consumer unit £1,600.00
Drainage pipe installation £1,150.00
Hot/clod water distribution £1,400.00
Gas connection £800.00
radiators (2 new radiators) £430.00
Toilet GF 1st and 2nd fix £765.00
Kitchen 1st and 2nd fix £1,165.00
New boiler installation - Worcester Bosch Greenstar 8000+ 32kW £4,000.00
Honeywell T3R wireless thermostat £176.00
Commisioning and certificates of M&E £600.00
£0.00
"Work in the Toilet
"
Ditra matt £67.50
Tiling to the floor £112.50
Tiling to the walls £300.00
Extractor fan installation £389.00
"Kitchen
"
Extractor £350.00
Kitchen installation £2,700.00
Work top installation by others £0.00
Splashback installation by others £0.00
Ditra matt £1,000.00
Tiling to the floor £1,875.00

"Other
"
Installation and supply of Pocket door to the toilet £1,400.00
External surface preparing for new paving installation £1,200.00
New paving installation £2,100.00
Aluminium clad to new still column next to rear window not included in the scope £0.00
New windows and soor supply and install not included £0.00
External rendering and decoration not included TBC £0.00

This is just for building costs so all kitchen, windows etc is not included in the quote.

It seems in line with quotes I have had, I decided not to do the work! 😆

@lazybone1 i am feeling the same way at the moment. 🙈

We also decided not to go ahead with a small extension due to cost. The cost/benefit just didn’t work for us.

Incredibly helpful thread, thanks Op and other posters . Op - would you mind posting the other detailed quotes here when they come in?

I am starting to think this - realistically we are looking at a conservative estimate of £150k for nothing terribly exciting. That said, my kitchen is in tatters and dark so we can't leave it as is.

And someone asked about how big the extension is going to be and it's 2.28 x 1.03M - so not exactly huge!

Post a floorplan of your house, OP, and we'll see what smaller tweaks can be made!

We redid the kitchen and utility room instead. We moved the boiler outside to give us more storage space inside and totally rejigged the kitchen in a way that gave us a lot more space.

Here is the current layout - the store at the back is just a very old shed which is attached to the house.

Here you go - it's not a great photo, sorry

Can't you just knock through the wall to the utility room? And make the door to the outside a glass door. More space and light instantly.

That actually was our original plan.

If you send me a DM I can give you plenty of advice as I have completed numerous loft conversions and extensions on my portfolio of houses that I let out which are in your area. I have probably completed 17 or 18 kitchen extensions in SW London over the last 7 years so have a wealth of experience, really good contacts and I accurate budget costs.

We did an extension which went out about 2m across the back of our house so I don’t know maybe 6wide?!
SE but not London. It was £30k plus VAT. Was for everything except the flooring.

We didn’t need a new boiler or anything though. This was in 2021.

How long are you planning to stay in your house? The thing that sticks out for me is that you have used him before and were happy. That is SO worth keeping in mind.

£5k for skips is horrendous but the costs have massively shot up and in the end I got a small skip and took the rest of the clobber to the tip. It took me 4-5 trips but free!

How long are you planning to stay there and do you have an idea of values before and after the work?

If its your home for life then its worth having it exactly as you want it. If its home for the next 4-5 years then you are unlikely to see a return on the money so it may make sense to stick with your original plan, improve the kitchen and light and keep what’s left over for the next move.

Building costs have escalated - both materials and waste removal and good skills are harder to find. If you have good experience with this builder it makes sense to at least get his breakdown and quite a few of those costs will be relatively fixed. I’d be asking myself about the value gained for less than 2.5 square metre of space at that price.

@C8H10N4O2 - probably another 10 years or so.

Can you post the drawing of the extension layout you were/are planning? There might be aspects from that that you could do, without doing the whole extension.

For instance, could you put a downstairs loo where your old shed is now.

@202617thjan Ideally i’m not staying in this house more than a few yrs so it’s not worth it.

Thanks for all the comments - DH and I are meeting the builder on Monday and will go through our options.

On a slightly different things - has anyone had a loft done lately? I know they've also gone up massively but wanted to check by how much.

The important thing about a loft conversion is having a sealable lobby to an outside door (fire regs), which you already have in your hall, so that's good. Open plan houses have problems with loft conversions for that reason.

Good to know. Does anyone have idea of costs for recent lost conversions?

Probably best if you start a new thread about loft conversions. You'll get more relevant replies.

That's a detailed breakdown, which is actually a good sign. Many quotes arrive as a single lump sum with no visibility of what you're paying for.
A few things worth noting. The quote excludes windows, doors, external rendering, worktops and splashbacks. Those will add significantly to your final cost, potentially £10-15k+ depending on specification. So your real total is closer to £95-100k before any surprises.
The new boiler at £4k is bundled in. If you don't need one, that's worth discussing. Consumer unit at £1,600 feels on the high side — worth querying.
For a sub-2m extension in London, £84k before the excluded items is not unusual at current prices, but it's not cheap either. The fact it's itemised means you can compare line-by-line when your other quotes come in.
Get at least two more quotes against the same drawings and spec. The variation will tell you a lot.