Cost of renovations and extension

Calleja

Hi all,

We are hoping to buy a house which is a little dated and therefore we would like to do some work. It's a 3 bed semi detached house with garage. We'd ideally want to knock through to create a kitchen/diner (and leave the remaining reception room as the lounge) and add an extension to the back and / or side to create a bigger kitchen/diner. I'm also budgeting for a full rewire, new windows (including a bay window) and new boiler (replacement of current combi boiler). 

I've never done this before and we don't have anyone handy in the family. Everyone I know who has had extensions had them done a few years ago, so aren't sure of current prices. I've done some online research and wondered if anyone on here had some thoughts as to whether I am in the right ball park? It is very much ball park at the moment, our offer has been accepted but we are still awaiting surveys etc. But I just want a feel for whether I've completely overestimated/underestimated or somewhere about right! Or I've missed anything major! The floorplan estimates the total floor area for the house to be approx. 100sqm. I'm in NW England.

The total of the below comes to £137,963. 

Thanks in advance for any advice! 

Item	Estimated
Rewire incl moving fittings	£6,000.00
Replaster	£5,500.00
New windows	£10,000.00
Extension (20msq)	£48,000.00
Extend driveway	£3,000.00
Knock through	£3,750.00
Re-render	£12,000.00
New kitchen	£20,000.00
Redecorate	£500.00
Carpets/flooring	£2,000.00
Boiler	£3,000.00
Other extension costs	£5,613.00 (architect fees, planning etc)
Extension doors and windows	£8,100.00
Flooring extension	£2,500.00
Underfloor heating extension	£5,000.00
Misc extension eg extractor fan, skirting etc	£3,000.00

rentalforever

Architecture fees and planning: We paid just over £4k for technical drawings, structural engineering, building control, planning submission and SAP certs and that was in the South East a year ago. We knew what we wanted and briefed it in, they did the rest. If you’re looking for someone to help you work out what you want and you need mood boards, 3D renders, interior design, multiple site-visits and the rest then £5k is under budgeting. Costs for that sort of thing start at £10k.

Flooring: What’s the difference between flooring extension and carpet/flooring line items? Do those prices include materials or just labour? We had 60 sqm of final flooring plus oak cladding for the stairs. That must have come to about £6-8k by the time all was said and done. About £4k in materials and the rest in labour. We had to do some light sanding and oil the stair treads and risers ourselves. If your subfloor needs work and material then that’s extra.

Kitchen: For a small/medium kitchen with a mid-range finish, quartz worktop from £3-6k, £6-8k on cabinets. Integrated appliances plus American fridge freezer, £3-5k. Cabinet fitting and services install will be extra on top of those costs. Then there’s flooring, tiles, are you using a vented extractor hood and does a new hole need drilling, any special lighting, boiling tap supply and install? £20k is a lot of money and seems a lot but the costs can escalate quickly here.

Tip: If you’re getting appliances and they’re not in stock in the usual shops then you’ll need to order them now if you want them arriving within the next 6 months. My oven ordered at the end of March is still nowhere to be seen - I’m thinking I might not see it before Christmas. There are plenty of options available that are readily available but if you’re particular about the model and you don’t see it stocked anywhere then it’s special order and that can mean a long wait in current climate.

Extension doors and windows: How big will the doors be? Are they bi-folds/sliding doors? Bespoke 6 metres of sliding doors from a mid-range provider might set you back about £12k. Doors off-the-shelf and smaller will be a lot less - prices usually available online.

Boiler: That seems on the low side, I’d budget £5k for a straightforward mid-range boiler job. If the boiler vent is inaccessible they’ll need scaffolding to do the job unless you’re getting it put up as part of other works already then that’ll be extra.

Redecorate: Is that price for you to do it or to hire someone? I’d be surprised if you can get supply and labour for £500 to redecorate which I assume you mean painting, caulking, etc.. Maybe if you get the absolute cheapest paint available and an amateur handy person to do it you might achieve that

Doozergirl

Not a bad ballpark.  We usually get people thinking they can do the same for about £100k less than you've worked out, so congratulations on that.  

There's always swings and roundabouts, some will be more, some less, but budget looks realistic.  I take it you're planning to do the decorating? 

Redwino222

If it helps my extension started last week.

it’s a wrap around and about 25m2 - costing £60k.  I have budgeted £20k for the new kitchen, £10k for the utility room and £10k for flooring (flooring is for all downstairs- 8O m sq).

so £100k just for a kitchen extension and new utility room! I am hoping I have built in enough contingency for price rises.

extension costs includes electrics and plumbing.

I have already spend £3k on architects, structural engineer and planning fees.  A depressing £1k went to live the gas meter!!!

DRP

Redwino222 said:

If it helps my extension started last week.

it’s a wrap around and about 25m2 - costing £60k.  I have budgeted £20k for the new kitchen, £10k for the utility room and £10k for flooring (flooring is for all downstairs- 8O m sq).

so £100k just for a kitchen extension and new utility room! I am hoping I have built in enough contingency for price rises.

extension costs includes electrics and plumbing.

I have already spend £3k on architects, structural engineer and planning fees.  A depressing £1k went to live the gas meter!!!

We’re just finishing a similar sized 5x5m extension, and ours is coming in around the same price. A kitchen diner extension , kitchen not included. 

Redwino222

DRP is that £100k or £60k for the extension? 

DRP

Redwino222 said:

DRP is that £100k or £60k for the extension? 

That’s 60k for the extension with Karndean flooring.

Calleja

Thanks everyone for the responses! It is a wish list - none of it needs doing - but I am keen that if there are big messy jobs to do, we try and do it all in one go rather than live in a mess for years! The flooring in the rest of the house can probably wait and we will decorate ourselves to keep costs down. Things such as the driveway is definitely a desirable so that could wait too. 

I get confused with websites which give estimates for the costs of extensions by sq metre - they are helpful but it's never completely clear what they include (or more importantly, don't include). But from your responses, I'm hoping that my budget is somewhere in the right direction. Thanks all! 

Calleja

Just an additional thought @DRP & @Redwino222 - I've budgeted separately for the doors and windows of the extension - do your costs include these? Or is that an additional cost on top of your £60K?

Thanks.

Redwino222

My £60k includes doors and windows, plastered out with electrics and plumbing.  

Buy flooring and kitchen fitting will be extra on top of that.

im not getting the fancy bi folding doors though - just French doors.  

DRP

Calleja said:

Just an additional thought @DRP & @Redwino222 - I've budgeted separately for the doors and windows of the extension - do your costs include these? Or is that an additional cost on top of your £60K?

Thanks.

3.2m aluminium sliding doors (taller than average too, so a bit more expensive) & an adjacent aluminum window (1000x500) included.

As an aside, I wouldn't go for white aluminum again - looks quite scruffy compared to dark grey I had previously as any tiny 'gaps' between panels are accentuated.


Also if you're getting Karndean, make sure your builder is an approved fitter or includes the price of hiring one in the quote. We're having no end of problems because our builder has cut corners with subfloor prep and fitted the karndean themselves...