An Architect’s Guide to Bathroom Renovation Costs in the UK
Explore average costs with real project data, plus budgeting tips and ways to save on your dream bathroom renovation.
Aron Coates, Architect, BA (Hons), BArch, ARB | Designs in Detail | October 2024
Renovating a bathroom is a great way to enhance both the quality of your home and its value. However, understanding the costs involved is crucial to avoid overspending.
Using cost data from recently completed projects, this guide will help you navigate the various expenses associated with bathroom renovations in the UK, helping you make informed decisions when planning your project.
Supply and Installation
Before we get into specific costs, we should briefly summarise what goes into costs.
Building costs are essentially comprised of two parts:
Supply, the cost of materials, fixtures and fittings.
Installation, the cost of labour to install the component parts.
When budgeting for a project we need to keep both in mind. For example, choosing an inexpensive supply item can cost you more overall than an expensive item if it’s more time consuming to install.
When compiling builder quotes, separate supply and install costs, wherever possible. You’ll be able to manage your budget much more effectively and keep better control on costs.
When discussing prices, builders often quote exclusive of VAT, adding it at the end of their estimates. To avoid unexpected costs, keep these points in mind:
Ensure VAT is included in all cost discussions. This prevents any unpleasant surprises before work begins.
When budgeting for supply costs, deduct VAT from individual items for consistency. This prevents potential overpayment. As a non-trade customer, items you purchase directly from suppliers will include VAT, whereas VAT-registered builders can purchase items without VAT.
VAT is typically set at 20% for renovations, but you may be eligible for discounts on certain works, such as those that improve energy efficiency.
Average Bathroom Renovation Costs
While several factors affect costs (which I’ll cover later), expect to pay on average for the renovation of a typical family bathroom:
£5,000 plus VAT for a simple upgrade and redecoration.
£10,000 plus VAT for a complete renovation, including strip-out and installation to a good specification.
In excess of £10,000 plus VAT for a high-end renovation.
For a typical family bathroom of about 6-9 square metres, here are some key installation costs:
Plumbing: Fitting a new bathroom suite – bath, basin, and W.C. – costs about £1,200-1,500 plus VAT, including labour and general building materials like pipework and fixings. Plumbing a heated towel rail will cost about £350.
Walk-in shower: Waterproofing, re-boarding, and plumbing a walk-in shower will cost about £1,200-1,500 plus VAT.
Electrical installation: For downlights, power sockets, and an extractor fan, expect to pay about £500 plus VAT, excluding the fittings themselves (lights, faceplates, etc.).
Electric underfloor heating: Expect to pay around £450 for materials and labour.
Tiling: Tiling costs range from £30-60 per square metre plus VAT, depending on the type of tile and the area. Grout and sealants are normally extra.
Replastering: Replastering a typical family bathroom will cost about £500-750 plus VAT.
Redecorating: This will be around £400-700 per room plus VAT.
Joinery: A joiner will charge about £300 per day for built-in joinery such as cabinets, shelving, and boxing out.
Low-cost shower room by Aron Coates.
Supply Costs
When renovating a bathroom, you’ll need to budget for the following supply items:
Bath tub, waste, and taps
Wash hand basin(s)
Basin taps, trap, and waste
W.C. pan and lid
W.C. cistern and flush (if concealed)
Toilet roll holder
Shower head(s) and controls
Shower screen
Shower tray and waste (for a walk-in shower)
Heated towel rail and valves
Cabinets and storage units
Mirror(s)
Tiles and grout
Tile sealant (if required)
Extractor fan
Ceiling lights (downlights or others)
Wall lights (if required)
Faceplates
Hooks and rails
Paint
Silicone
An average supply cost for these items for a medium specification will be around £7,000-8,000. If you have a shower over the bath, the total supply cost will be slightly less.
Reductions can be made by focusing your expenditure on quality tapware while using more cost-effective items, such as ceramic tiling.
Shop around and get discounts, but be clear about who purchases the items – you or the builder.
Generally, it’s better to send the builder a schedule of all the items you’d like to include in the renovation, complete with retail prices, product descriptions, reference codes, and delivery times.
This way, the builder can take responsibility for the delivery. If you decide to purchase items yourself and there are delays, you’ll be responsible for any additional costs the builder incurs.
Factors Influencing Bathroom Renovation Costs
Size: Larger bathrooms require more materials and labour, increasing costs.
Location: Costs in London will be higher than in other parts of the country. Similarly, living in a remote area may add extra costs.
Scope of work: Minor updates are less costly than full renovations.
Quality of finishes and materials: High-end materials like marble or designer fixtures will increase supply costs.
Type of finishes: Small or irregular-shaped tiles can add to installation costs, as can non-standard tile patterns.
DIY vs Professional Installation: While DIY projects can save money, hiring professionals ensures quality and efficiency but comes at a higher price. A certified plumber and electrician will be needed for compliance with building regulations.
Plumbing: If existing plumbing needs upgrading or repositioning, costs will increase.
No matter your budget, these tips can help you stay cost-efficient:
Plan thoroughly: Provide detailed drawings of the bathroom design, including sanitaryware positions, tiled areas, and electrical and heating layouts, so everything can be properly costed and planned.
Check the drainage: Position the WC close to a soil vent pipe (SVP) to minimise plumbing costs and simplify drainage.
Check the existing structure: Plot the positions and span direction of floor joists and other structural members (such as steelwork), as you’ll need to navigate these when installing new pipework.
Prioritise quality: Invest in high-quality fixtures and fittings for durability.
Shop smart: Look for deals on supply items without compromising quality.
Hire professionals: Choose skilled professionals to avoid costly mistakes down the line.
Bathroom Renovation Checklist
Here’s a quick summary of the key considerations when planning your bathroom renovation:
Separate supply and installation costs in your budget.
Factor VAT into all cost estimates.
Expect average renovation costs between £5,000 and £10,000, depending on scope.
Plan thoroughly to avoid unexpected costs.
Shop around for the best supply deals.
Hire experienced professionals to ensure a high-quality finish.
The information provided in this article is intended for general guidance and educational purposes only. For specific expert advice on your project, consult a skilled residential architect featured on Designs in Detail.
About the Author
Aron Coates is an architect with over two decades of experience, working on projects ranging from historic building restoration to contemporary home design.
