This page offers guidance on major home renovation costs, based on real data from our projects over the past 14 years. Figures shown are VAT exclusive so you would need to add VAT at the prevailing rate. Project management and any of our design work is also excluded.
We’ve brought older figures up to January 2016 economic conditions (unless otherwise stated) by applying an annual inflation factor of 3.5%. However, we should point out that, since the EU Referendum, we’ve seen prices increase in some areas (construction, kitchens and bathrooms, and other products) by around 15-20%. You will need to take this into account when considering your project in current economic conditions. We’ve written separately on this in our blog concerning the impact of Brexit on home renovation.
Whilst it is important for you to see major home renovation costs, it is equally important to understand how you can control those costs. We spend significant time planning and preparing to make sure that total costs are known before our clients commit to a project; we then manage cost closely. To explain how we do this, we’ve provided further links at the foot of this page to our guides on how to renovate a home successfully. They explore the factors that affect cost and how you can avoid cost increases as the project proceeds. We hope you find these helpful.
We designed and delivered all of what follows, unless otherwise stated. This included facilitation of planning permission, building regulations, and party wall agreements. We produced designs for all the projects and oversaw contractors and trades. We also sourced all the fixtures and fittings: kitchens, bathrooms, floors and so on. Separately, you can read more on our home renovation and interior design service.
2 storey knock through extension with en-suite and open-plan kitchen diner – 30m2 additional floorspace
Here is the extension nearing its finishing stages.
and below is an internal view … The main horizontal steel is visible here because other steels already existed below ceiling level (usually we plan to lose the steel in the ceiling space to create a perfectly flat ceiling). This main steel shows the line of the original building through which we extended.
Major home renovation costs:
Structural and building work – £58 000
Plumbing – £7000 (inc UFH on ground floor and en-suite bedroom on first floor)
Joinery – £4000
Electrics – £8000
Decoration – £4000
Kitchen – £15 000 (medium spec with high spec worktop and splashback)
Flooring – £3000
En-suite fittings etc – £5000 (high spec)
Architect – £3000
Structural Engineer – £1000
Total – £118 000
You can see how a detailed description and more photographs of this house undergoing renovation on our page entitled two storey extension.
Also, to ensure that you cover everything in your home renovation project, you may enjoy reading our guide to property renovation.
Glass Side Return Extension with kitchen – 30m2 kitchen diner overall with 10m2 additional floorspace in extension
with interior views when completed:
glazed extension and roof
Major home renovation costs:
Structural and building work – £27 000
Glass structure – £39 000
Plumbing – £3000
Joinery – £3000
Electrics – £4000
Decoration – £2000
Kitchen – £24 000 (high spec)
Flooring – £3000
Architect – £3000
Structural Engineer – £3000
Total – £111 000
For a documentary record of this project, please read our page on the side return extension. It was carried out in conjunction with the basement conversion described below.
We have also produced a guide on the technical steps to house renovation; if you are interested in how to design a kitchen, you might also care to see our kitchen design guide.
Basement Excavation (full dig out and extensive underpinning) – small – 18m2
and finished:
Major home renovation costs:
Structural and building work – £48 000
Plumbing (inc UFH) – £5000
Joinery – £3000
Electrics (inc home network) – £5000
Decoration – £600
Architect – £1500
Structural Engineer – £2000
Party Wall surveyor – £3000
Total – £65 000
You can read more about this basement conversion along with our blog on how to convert a basement.
Side EXTENSION with glazed roof
Close up of kitchen:
and Sitting Area with Home Cinema Wall:
Major home renovation costs (2018 prices):
Structural and building work – £24 190
Aluminium doors and glazed roof – £15 000
Plumbing (inc UFH) – £3400
Joinery – £1800
Electrics (inc home network) – £3800
Decoration – £2600 (including labour to lay tiles)
Architect – £1000 (note Architect used our measured survey so saved £600)
Structural Engineer – £1650
Kitchen – £17 730 (includes cabinets, appliances, worktop, splashback, sink and tap)
Floor Tiles – £3000
TV Cabinetry – £6250
Total – £80 420
Basement Conversion (part excavation to existing space) to incorporate new high spec kitchen with access to garden through folding sliding doors (quotation) – medium – 50m2
Total – £165 000
Basement Conversion (part excavation to existing space) to incorporate new bedroom with en-suite and access to garden (quotation) – medium – 35m2
Total – £80 000
Side Return Extensions for 2 neighbouring properties (13m2 additional floorspace each side)
We built 2 neighbours’ extensions creating two open-plan kitchen diners, one with a utility.
The open plan kitchen diner in one of the properties:
4 tenders were received. Total prices for both were similar; one neighbour required more work, but the other preferred more expensive fittings. Economy of scale saved each client around 10% of the construction and statutory costs. 50% was saved on Project Management.
Property 1 (inc small utility):
Planning drawings – £1100
Building Control – £1600
Structural engineer – £650
Structural and building work – £30 530
Frame structure and 3 roof lights – £6500
Plumbing – £4450
Joinery – £4400
Electrics – £2920
Decoration – £1680
Units – £7600
Appliances – £1100 (some re-used)
Worktop – £1800
Splashback – £800
Flooring – £1900
Other – £2350
Level garden, remove soil – £2300
Supply and fit fence to 3 sides – £4750
Build and render garden wall (4m x 1.5m) – £1600
Build 4m deep patio slab across property – £1750
Build face wall to patio and cast steps to garden – £1800
Supply slabs and lay patio (24m2) – £2400
Supply and fit hardcore and astroturf (£80m2) – £3900
Total – £88 000 + VAT
Note – from the 4 tenders, the highest price was around 20% over the price shown above.
Property 2:
Planning drawings – £1100
Building Control – £1600
Structural engineer – £650
Structural and building work – £31 480
Frame structure and 3 roof lights – £6500
Plumbing – £4800
Joinery – £2100
Electrics – £3350
Decoration – £1120
Units – £11 500
Appliances – £3964
Worktop – £4600
Splashback – £1300
Flooring – £1500
Other – £1800
Total – £77 264 + VAT
Note – from the 4 tenders, the highest price was around 25% over the price shown above.
You can read a documentary on this project under the heading side return extension.
Small single-storey Fill-in Extension with internal re-modelling – 8m2
Structural and building work (only one new external wall, but includes 4m steel to open out side wall, and new flat roof section) – £12 000
Plumbing – £1000
Joinery – £1000
Electrics – £1500
Decoration – £1500
Total – £15 000
3 Bed Edwardian House Renovation (typical British terrace house) with small extension, and internal wall opening to create large kitchen diner
internal view when finished …
Major home renovation costs:
Structural and building work – £26 000, of which £12 000 for small extension (2m2)
Roof – re-felt and batten, inc scaffold – £4000
Re-render and paint rear elevation – £2000
Plumbing – £7000
Joinery – £12 000
Electrical – £5500
Decoration – £9000 (whole house)
Kitchen – £14 000 (medium spec)
Total – £80 000
Read more about this full house renovation in Bristol.
Bedroom with en-suite over garage (Quotation)
With suitable foundations: £35 000 – £40 000
To rebuild if foundations unsuitable: £65 000 – £70 000
3 Bed Edwardian House Renovation (typical British terrace house with bedroom 4 in loft) – complete renovation (inc. new flooring, bathroom, create en-suite for existing loft room) – except for kitchen.
living room when furnished …
Major home renovation costs:
Structural and building: £23 000
Plumbing: £13 000
Joinery: £9000
Electrics (new): £7000
Electrics (re-wire): £6000
Decoration: £8000
Bathroom fittings: £6000 (high spec)
En-suite fittings: £2000
Carpets: £4000
Total – £78 000
We’ve recorded more information about this house renovation in Bath.
3 Bed Victorian House Renovation (typical British semi) – complete renovation (inc. new flooring, bathroom and external work) – except for kitchen
sitting room when refurbished
dining room before work started
and when renovated and furnished
Major home renovation costs:
Structural and building – £25 000
Plumbing – £13 000
Joinery – £8000
Electrics – £11 000
Decoration – £11 000
Oak flooring (2 reception rooms and hall) – £2500 (labour of £2200 in joinery price)
Carpets – £2000
Garden Excavation (5m3) and new retaining wall – £5000
Bathroom fittings – £7000 (high spec)
Total – £85 000
Here you can read more about this Victorian house renovation in Bath.
Kitchen-Diner Knock-through, with folding sliding doors to garden
dining area when complete
Major home renovation costs:
Structural and building work – £28 000
French Doors – £7000
Plumbing – £10 000
Joinery – £3000
Electrics – £5500
Decoration – £1000
Kitchen – £25 000 (high spec)
Total – £80 000
We’ve produced a detailed page where you can read more about this knock through kitchen extension in Bath.
Lean-to, single storey side extension with access from kitchen to create utility and WC – 10m2
Total (including building work, new roof, floor slab etc, WC suite) – £37 000
Property Renovation (5 bed) with knock-through kitchen diner and removal of chimney breasts (no new kitchen)
Structural and building work – £15 000
Plumbing – £4000
Joinery – 5000
Electrics – £12 000
Decoration – £5000
Flooring – £8000
Carpets – £4000
Vinyl floors – £1000
Total – £60 000
SINGLE STOREY EXTENSION 5m x 3m WITH TILED, PITCHED ROOF, COMPLETE (REGULAR CONTRACTOR’S PROJECT) – 15m2
Total (including building work, new roof, floor slab etc) – £43 000
SINGLE STOREY EXTENSION 3.5m x 8m WITH TILED, PITCHED ROOF, rubble stone construction (REGULAR CONTRACTOR’S PROJECT) –
Total (including building work, new roof, floor slab etc) – £60 000
Two single STOREY EXTENSIONs on same property WITH TILED, PITCHED ROOFs (REGULAR CONTRACTOR’S PROJECT) – Total 60m2
Total (including building work, new roof, floor slab etc) – £110 000 basic construction and building work; £150 000 including en-suite and kitchen.
30’s semi – extension options (current price estimates – project pending)
For this project, we provided price estimates for several options of which two are shown below:
Option 1: Two-storey side extension with additional wrap-around single storey glazed extension (knocked through from existing to create open-plan space) with additional utility and new bathroom:
Structural and building work – £95 000
Bifold doors and rooflights – £13 000
Extra to remove 2 pairs of chimney breasts right through and decorate – £8500
Simple driveway modifications – £3000 – £4000
Install central heating – £4800
Other plumbing inc underfloor heating – £5500
Kitchen installation – £2500
Rewire House – £6000
Project specific electrics – £5200
Decoration – £3800
Kitchen (medium spec inc flooring) – £14 500
Utility fit – £1500
Bathroom fittings (inc flooring) – £2800
Other fittings and furnishings for extra rooms – £2500
Total – £168 000
Option 2: Wrap-around single storey glazed extension (knocked through from existing to create open-plan space) with additional utility:
Structural and building work – £40 000
Bifold doors and rooflights – £15 000
Extra to remove 2 pairs of chimney breasts right through and decorate – £8500
Simple driveway modifications – £3000 – £4000
Install central heating – £4000
Other plumbing inc underfloor heating – £4000
Kitchen installation – £2500
Rewire House – £6000
Project specific electrics – £4000
Decoration – £1400
Kitchen (medium spec inc flooring) – £14 500
Utility fit – £1500
Total – £101 000
Major home renovation costs
We hope you’ve found these indicative costs from real projects informative. In our experience they help clients to budget more carefully and to enter into renovations with their eyes open.
As we said at the top, the final cost is influenced by factors including management of the renovation from start to finish. For instance, we spend a lot of time getting the design and specification right – if you don’t, then you run the risk of significant cost overruns. To help you manage your renovation successfully and control the cost, we’ve included the following guides which we hope you find helpful.
Other Guides
We offer more advice for successful home improvements in our various guides. Here are some links.
- Controlling the Cost of Home Improvements – Making sure you’ve considered everything in the total project cost
- Property Renovation Guide – The steps to a successful renovation including your choice of main contractor.
- How to Renovate a Property – Preparing for a home renovation and a guide on services offered by various professionals.
- How Much to Invest in a Property – Considerations on the amount of money you might consider spending on home improvements.
- Home Design – If you are struggling to visualise your new home, this shows how basic 3D images can help without costing the earth.
- Property Renovation Companies – What a good property renovation company should do, and how they can help you.
- Kitchen Design – Practical steps for designing your dream kitchen
- Bathroom Design – Considerations for a stylish yet practical bathroom
We also provide a planning applications service for major projects in Bath, as well as engaging structural engineers and architects in producing building control and construction drawings.