With ever-increasing house prices, many homeowners are choosing to renovate their properties rather than move. It’s one of the most popular topics I get asked about at the Homebuilding & Renovating Shows.
Whether it’s knocking through a kitchen-diner, converting a loft or refurbishing an outdated property, the question is always, ‘How much does a renovation cost?’
Based on years of experience helping people prepare accurate and realistic cost plans for renovating a house, here's what I recommend you budget if an upgrade is on the horizon.
Average total renovation costs
Of course, every project varies, but a full renovation of a three-bed semi-detached property tends to cost between £70,000 and £110,000 in the current climate.
That encompasses everything from rewiring and replastering to installing a new kitchen, bathroom, flooring and heating system. Structural changes, extensions or high-spec finishes will add to that figure, and often significantly.
Most importantly, the expense is not just materials, plant and labour, but also the decisions you make at every stage. My guide breaks down renovation costs, budgeting and planning, and what to expect to pay for every typical job.
The costs given are all based on the mid-range refurbishment of a 1930s three-bed, semi-detached suburban house in a UK town. This is the typical weekly project for which I’m asked to provide a cost plan before work commences.
It is worth noting, however, that the principles apply across most property types.
Cost factors to consider
The cost to renovate can be dramatically different based on early decisions. Here are the most important factors that will affect your renovation budget:
Location – Building prices differ significantly across the UK. In London and the South East of England, labour can cost 25-30% more than in places like the Midlands, North West or parts of Wales.
Access – If your trades can’t park conveniently or the materials must be ‘hand-balled’ in and out, expect delays and added costs.
Age and condition of property – Older homes add character, but they can also cost more. Rotten floor joists, vintage electrics and plumbing, damp or inadequate insulation are things to consider. Period houses may require lime plaster, breathable insulation and specialist trades, which will add to your budget.
Specification and design – All of your decisions regarding spec and design affect costs, from basic uPVC windows to bespoke hardwood casements, or laminate worktops and quartz. Last-minute variations (the dreaded design creep) are one of the biggest cost drivers, so get the spec right in the first instance.
Extent of renovation – How intrusive is your renovation, are you taking all the rooms back to the bare brick? Are you knocking through a wall to create an open-plan layout? Is your new kitchen in the same position, or are you relocating it?
Work that includes structural changes, steelwork or relocating services costs more and, in some cases, significantly more.
Professional trades vs DIY – Carrying out some of the work on a DIY basis can save money. Decorating bedrooms, tiling the WC or utility room, small demolition and rip-out, and even kitchen fitting are all within the scope of most homeowners. Don’t cut corners on structural or technical work, especially electrics and plumbing, as this can lead to compliance problems.
Planning – Even before you sign up to buy or work on a project, invest in a full building survey, especially for older homes. A full survey will identify structural issues, damp, condition of the roof, timber decay and signs of movement. With this, you can make informed decisions and avoid expensive surprises later. Use the right experts and get them involved early.
A builder will use the full potential of the property. A quantity surveyor will cost out the work and indicate where costs can be trimmed via ‘value engineering’. Structural engineers are essential for any project that includes knock-throughs, loft conversions or large extensions.
Installing a new heating system
Replacing an entire central heating system consists of removing the current boiler, fitting a fresh condensing boiler (most likely gas, while we still can as this is changing in 2035), new radiators or underfloor heating (UFH), thermostatic valves, changes to pipework and programmable controls.
● Typical cost: £5,000 to £7,000
● Add for UFH: £75 to £125sqm
● Boiler-only replacement: from £2,000
The final cost will depend on a number of factors, such as your boiler size (combi versus system), whether you opt for radiators or UFH, the number of zones you need, system cleaning/flushing and smart control integration.
Bleeding your existing system when fitting a new boiler will extend its life and prevent premature failure, but it’s one that plumbers could easily forget to carry out. Adding a magnetic filter to trap dust and debris is also a good idea.
Rewiring your house
Older electrical installations often aren’t up to today’s standards and insurers or mortgage companies may insist wiring is replaced during a renovation.
● Average price: £4,000 to £6,500.
This would include rewiring light circuits, socket rings, installing a modern consumer unit, and taking it all up to BS 7671 standards.
The size of your house and the number of fittings you require will have an impact on the price, as will whether the walls are chased or surface- mounted and if you have lath and plaster ceilings.
To keep costs under control, it pays to think ahead and plan your switch and socket positions and quantities thoroughly at first fix, as altering afterwards will mean re-chasing and replastering.
Replastering walls
Older houses sometimes require full replastering which leaves the decorating surface smooth, but it’s messy, costly and time-consuming.
● Typical cost: £4,500 to £7,000.
This usually includes skimming all walls and ceilings as well as bonding and repairs where required. Prices will vary depending on the level of surface preparation (hacking off), ceiling height, whether you are drylining or going for wet plaster and the disposal of waste.
To improve your home’s energy efficiency, it’s worth the additional expense of drylining with insulated plasterboard in cold rooms.
Adding a new kitchen
The kitchen is perhaps the key space in the house and frequently the most costly room to remodel.
● Average price: £10,000 to £15,000, but a basic kitchen could cost £8,000 with high-end designs costing £25,000+.
The average price for a new kitchen includes brand-new appliances, worktops, plumbing, electrics, wall and floor finishes and fittings. The final spec of your finishes will have a big impact on overall costs, for example solid surface versus laminate worktops, flatpack versus bespoke joinery and freestanding versus built-in appliances.
If you are modifying the existing layout, this is also likely to incur additional costs as pipework and electrics may have to be re-routed or extended. For better deals on appliances and units, shop around and buy online, especially during sales events.
Installing a new bathroom
A new bathroom suite entails taking out the old suite, fitting updated ventilation, pipework, tiling, waterproofing and sanitaryware.
● Average cost for a bathroom: £5,000 to £7,500.
● Average cost for an en suite: £4,000 to £6,000.
Your choice of tiles and the number of walls you choose to tile can be one of the biggest cost factors, along with your choice of hidden versus exposed pipework and whether you opt to keep the existing layout.
You can reduce your tile costs significantly without sacrificing much in terms of aesthetics by tiling less important areas (such as WC walls which can be painted) to half height instead of full height.
Replacing the roof
A completely new roof is necessary for many older properties. A full roof replacement means removing the old tiles, replacing the battens, tiles and breathable felt, plus replacing the fascia boards and soffits.
● Average cost for a main roof: £8,000 to £12,000.
● Average cost for a flat roof: £2,000 to £4,000.
If timber repairs are also needed or you want to upgrade insulation, you’ll need to allow for additional budget. Your final tile choice will also impact the price, with concrete tiles being more affordable than natural slate.
Remember to factor in scaffolding costs, which can range between £1,500 and £3,000 for a typical home.
New doors and windows
In addition to increasing comfort, energy-efficient glazing is frequently a noticeable feature of remodelling and can add value to your home.
● Average cost: £6,000 to £8,000 for a three-bedroom house in uPVC, or £9,000 to £14,000 for aluminium/timber units.
Typical cost implications include your choice of frame materials, the number of openings, whether you opt for double or triple glazing, door styles, trickle vents and fire regulations, as fire-rated doors are more expensive than standard designs.
It’s worth remembering that you don’t always need triple-glazed windows – double glazing is cheaper and complies with U values.
Flooring upgrades
Although it is frequently put off, flooring replacement should be planned in advance to avoid upheaval at a later date.
● Typical cost: £4,000 to £6,500. Laminate flooring: from £25 sqm; engineered wood flooring £50 to £90 sqm; luxury vinyl tiles (LVT) £45 to £70 sqm (including fitting).
As well as your floor specification, costs could increase if extra preparation is needed before fitting the floor, such as removing the old flooring. Soundproofing measures or adding an underlay will also have an impact. To save money, purchase flooring during seasonal sales and always factor in 10% waste for offcuts and repairs.
Damp proofing measures
Moisture problems are common in older homes, but there are different causes. A full survey will help to identify the likely cause and suggest the measures you need to take.
● Cost: £2,000 to £5,000.
This could involve tanking, damp membranes, DPC injection, or repairing external flaws (such as clogged gutters).
It’s always best to have the causes determined by an impartial building surveyor as some contractors may suggest needless work, so don’t rely solely on their advice.
Painting and decorating
If you plan to sell, a professional finish makes all the difference.
● Average cost: £3,000 to £5,000.
Cost factors will include the paint type (budget vs designer), quantity of coats needed, preparation time and ceiling heights. If money is tight, carry out bedrooms or simpler rooms on a DIY basis and hire decorators for the difficult areas such as ceilings and stairs.
Converting the loft
One of the most common remodelling projects in the UK is a loft conversion. Although building regulations approval is always necessary, they can frequently be completed under permitted development rights and will add valuable space to your home.
● Average price: £40,000 to £55,000 (£1,100sq m) for a converted rear dormer loft with a single bedroom and a private bathroom
Although dormer windows cost more than Velux rooflights, they frequently increase the head height that can be used in the space. Structural reinforcements, the installation of a loft staircase, the construction of dormers, roof coverings, insulation and interior fit-out are all important cost considerations, too.
Keep in mind that updating fire safety regulations throughout the house is usually necessary when converting a loft. This could entail setting up smoke alarms with mains connections and fire doors on every floor.
Adding a rear extension
An open-plan kitchen, dining and living space can easily be achieved with a single-storey rear extension. However, because of the structural steelwork, foundations and roofing required, it may be more costly than most people think.
● Average price: £50,000 to £70,000 (from £2,500sq m) for a 4x5m single-storey rear extension
Excavating, foundations, block and brick walls, roof coverings and structure, structural steel, glazing (sliding or bifold), plastering, electrical work and finishes are all included in this cost.
Decoration, flooring and kitchens are frequently extras. The cost is greatly impacted by the quantity of glazing, such as skylights, roof lanterns and bifold doors, with aluminium or wood frames raising the overall cost by several thousand pounds.
Find out how much your dream extension could cost using our bespoke extension cost calculator.
Converting a garage
It is quite popular these days to turn an integral or attached garage into living space by undertaking a garage conversion using permitted development rights. This is one of the most economical ways of adding an extra room to your home.
● Average price: £12,000 to £20,000.
Insulating the walls and floor, replacing the garage door with windows or doors, extending your heating and electricity from the rest of the house and completing the interior finishes are typically all part of the project.
Make sure the area conforms with current thermal regulations and that the floor level is raised to match the rest of the house. Additionally, you might need to think about ventilation, particularly if you’re turning it into a bedroom.
Additional costs
Beyond labour and materials, even relatively simple projects have extra expense. Although these can change, you should always account for them when creating a budget.
Professional fees
- Architect: £1,500 to £4,000, depending on service level
- Structural engineer: £400 to £1,200 for calculations and site visits
- Planning consultant (if needed): £500 to £2,000
- Project manager: £2,000 to £5,000+
- Quantity surveyor (QS): from £350 for an early cost plan and £950 for a Bill of Quantities
Make sure you verify what is and is not included in the service, as some design-and-build firms include these costs in the overall quotation. Always aim to get a fixed fee too, rather than a percentage that is based on the build cost.
Planning and Building Regulations fees
- Planning fee (extensions, alterations): £613 (England)
- Building regulations drawings and submission: £1,000 to £2,500
- Party wall agreement (if required): £1,000 to £2,000 per neighbour
- Site surveys (topographical, drainage, asbestos, etc): £300 to £1,500
Many homeowners overlook these expenses. However, they may account for 10-15% of the project’s total budget.
Getting quotes for your renovation
It is crucial to get the right trades on board. Start by creating a precise scope of work or specification, complete with layout drawings and a simple timeline.
My mantra is to always go out to tender to get a minimum of three written, detailed quotes from builders or individual trades.
Every quotation should include:
- VAT where applicable. Clearly define what is and is not included
- Lay out terms for payment and a work schedule
- Provide information about guarantees and insurance
- Give examples of prior work
- Type of contract to be used
- Priced Bill of Quantities/Schedule of Works
Avoid lump-sum quotes that don’t provide a breakdown. Determining which portion of the work is covered can be challenging if problems occur. Therefore, use a QS to produce a Bill of Quantities for tender, contract sum and valuation purposes.
Request quotes from builders for similar tasks as otherwise comparisons become challenging. Additionally, confirm that the provisional amounts (like kitchen or bathroom) are feasible.
Ways to save on renovation costs
There are many ways to be budget-friendly without sacrificing quality, it’s what quantity surveyors refer to as ‘value engineering’.
Here are some tried-and-tested methods:
- Reuse or upcycle: sanding down floorboards, reusing bricks or retaining original doors can save money and maintain character
- Phase the works: working on a job in stages can help to spread costs, although it may extend timelines
- DIY: If you are experienced, taking on the project-management role yourself will save 10-15%
- Do your own buying: provide kitchens, bathrooms and floors direct to cut out percentage mark-ups
- Utilise industry standard sizes: made-to-measure doors, windows and joinery add considerable cost; remember anything ‘bespoke’ adds costs
- Avoid late changes: layout or spec changes halfway through construction incur delays and reworking cost, especially as the builder isn’t in a competitive tender situation any more, so can increase their margin on the variations
- Take VAT savings into account: some works to listed buildings or conversions will be zero-rated or reduced-rate – consult with a VAT specialist for advice
- Assess quotes: don’t choose the cheapest quote without understanding why it’s the cheapest. It’s better to pay a little extra for a good builder with clear pricing via a Bill of Quantities and good communication.
Renovating a home is an investment, not only financially but emotionally and logistically, too. Knowing clearly what the costs are at every turn can help homeowners make better decisions, stay within budget, and have the home they want without compromise.
The key thing is planning. Be clear on what you need, have an early cost plan prepared by a quantity surveyor and include a contingency sum of at least 12-15% for a typical renovation.
Choose contractors sensibly and be rational on what you can undertake yourself on a DIY basis. A well-organised renovation can add long-term value, comfort and character to your home.
To understand more about the process, find out the renovation truths experienced home renovators want you to know, and make sure you have realistic expectations of how long your renovation will take.
