Is the cost of extension seems expensive?

[ALT72]

Hi - apologies in advance for a long list of the work being done. Does the costs seemed high for an extension? We are also having a new downstairs loo created as well as a new utility room - both of which will be in the old kitchen.

Building work to include

• Rear extension 3530mm out x 4220mm wide (approx size)please note this will require planning approval
• Removal of the wall between the dining area and new extension
• Horizontal steelwork to support the existing back of the house-no vertical posts allowed for
• 1 x set of 3 panel aluminium bi folding doors on the rear wall of the extension
• Flat roof to the extension
• Brickwork finish to the new extension and garden side wall of new storeroom
• Foundations will be taken to a maximum of 1 meter deep included in the quote
• 1 x Flat glass roof light 2.5m x 1m
• 1 x tall designer radiator in the new kitchen area (rawmetal)
• 1 x plinth heater run off the central heating
• Hot and cold pipework to the new sink location
• Waste pipe to the new sink location
• Relocation of the soil pipe drainage to the new wc
• 1 x door casing to the utility and wc-customer to supply the doors
• 1 x chrome heated towel radiator in the utility room
• Hot and cold feeds to the utility room
• 1 x toilet with soft close seat
• 1 x sink with mixer tap
• 1 x stud wall to create the wc area
• 1 x chrome heated towel rail
• 1 x fan to the wc area vented through the store room
• Demolition of the existing outhouse and keep existing slates for customer to use as spares in the future
• Render the neighbour’s outhouse wall which was inside the outhouse that was demolished to provide a water barrier for the neighbour
• Removal of the existing kitchen
• Remove the skirting boards
• Remove the coving
• Block up the doorway from the dining room to the existing kitchen
• 1 x new doorway from the dining room to the existing kitchen with crittall style door (clear glass)
• Block up the wall in the existing kitchen to close off to the new store
• Replace fascias and gutters plus downpipe on new storeroom with black PVC and half round guttering
• The felt roof on the store room will be cut back and made good
• Reduce the length of the new store room
• New foundation for the new storeroom wall
• 1 x Single security metal door to the store room
• 1 x UPVC half glazed white door to rear of property with upgraded lock including alteration of brickwork and new lintel
• Re render the long wall where the side door is installed on the store room
• Remove outside skin of bricks to ground level to front of store room and rebuild with new brick
• Open up the chimney as required.
• Build new stud wall behind sink to create splashback area and upstand behind new sink area
• Plastering of the new extension, kitchen, utility room and wc-no plastering in the new store
• Mdf double sunk skirting boards in the extension, kitchen, utility and wc
• Remove waste from site
• No making good of the groundworks included.
• Price to be confirmed once structural engineer has completed the calculations- planning, building control and architect fees are at an additional cost
• Boiler move shown in additional items

Subtotal inclusive of vat £79,200.00

I think that sounds about normal. My daughter was quoted £50 k for a single storey extension inside plastered and electrics done but nothing else. I also think it depends where in the country you are as to how expensive it is.

I thought at least 150k. Bargain!

Wouldn't surprise me. We're hoping to get planning permission to push out our kitchen, a bit smaller than your dimensions I think. One of our neighbours is a builder so we asked him for a ball park figure to have an idea. £52 000 to a plastered finish, basic plumbing, basic electrics.
We're waiting on the planning permission to be approved before getting any more builders in but I'm not hopeful on prices. I'm guestimating £70 000 which I can't decide if it's worth it!

We are renovating and finding everything much more expensive than anticipated. If it helps, I look at what it would cost to buy an equivalent house (once the works are complete) and how much extra that would cost to buy vs staying put and doing the works. You'll probably find even at £80k, you'd not be able to buy an equivalent house for an extra 80k. If you can, maybe then consider if it's worth it. If there are no other factors that tie you to where you are.

Not what you asked, but I find it helpful to reason it this way. We're looking towards £80-100k now on a house I thought would cost £50k to renovate 😫 we've not extended, but have made significant improvements. I certainly couldn't afford to buy something similar once we are finished.

I'd say that sounds a bargain to be honest.
Extensions are so expensive.
We were quoted over £100k for a very similar job a year ago (south east England)

£66,000 plus vat seems very reasonable looking at that list. There’s a considerable amount of work on there. We have just started on a 3.5x3.5m extension off the kitchen. Nothing too out of the ordinary. 2 windows, door, underfloor heating and tile. Velux window in roof, Cotswold stone walls and reclaimed roof tiles (grade 2 listed house) skimmed, decorated, relocation of manhole and we are looking at about £30,000 plus vat. No changed to existing house apart from knocking through to the extension.

My loft conversion (small but included bathroom) last year cost more than that. A lot smaller and less work than you are having done. SE London. Materials and labour are not cheap.

I’m another one who thinks “bargain”.

Thanks all for taking the time to reply. This is good to know.

Are they reputable because it seems too cheap?!

Sounds very reasonable, but make sure you allow for anything that hasn't been included in the quote - the last time I had building work done in 2015 I ended up paying an additional £20k for things that weren't specifically included in the original quote.

I'm just in the process of renovating, not extending at all, a single storey house and that's going to cost more like £150k - I am trying not to think about it...

That seems very reasonable!
We just got quoted almost that much for a single storey 3.5m x 3m which is literally just a room!
We're not going ahead as its too expensive for us and over what we had budgeted.

I'd add £30k to that as a budget.

That's a good deal - how big is her extension?
Since she has not opted for anything else, will she have bare floors and no kitchen units? Will she do this herself or source it from somewhere else. Genuinely interested. Thank you.

hi OP @ALT72
where are you in the country?

I am in Cheshire.

This is a really good point! My quote was for less than I ended up paying, as didn’t include the costs of plastering, decorating, etc. Then there was the cost of floor coverings, everything for the bathroom etc.

Because I am a deeply nerdy person, I made a detailed spreadsheet of costs. It actually was really helpful.

Hi OP, out of interest, is the work being done by one company/contractor, or by several different companies?

It’s being done by one company who will project manage everything.

That sounds about right. Where about are you?

If you are in London I recommend Bespoke Glazing Design for the doors & flat roof.

How much will the new kitchen cost you?

I think it will be more in the 100k to 120k in the end because the builders will find issues/problems that need to be remedies

That seems more than reasonable.

Hi. Did you proceed with extension?
Who wre your contractors?
Hoping to have double storey extension in near future