Instant Cost Estimator

Renovation Cost Calculator

Get a personalised ballpark estimate for your London renovation in under 60 seconds. Select your project type, property details and specification level.

Current London Rates Updated Quarterly No Obligation
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Project Type
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Details
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Specification
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Estimate

What type of project?

Select the renovation that best describes your project.

Loft Conversion
House Extension
Kitchen Renovation
Bathroom Renovation
Basement Conversion
Full Refurbishment

Project Details

Tell us about your property and project size.

sqm

Specification Level

Choose the finish level that matches your vision.

Standard

Quality materials, clean contemporary finish

Most Popular
Premium

Designer fixtures, engineered oak, stone surfaces

Luxury

Bespoke joinery, Carrara marble, smart home integration

Your Estimate is Ready

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How London Renovation Costs Compare

Core build cost per square metre before VAT and project-specific fees, based on current London guide rates.

Project Type Standard Premium Luxury
Loft Conversion £1,100 – £1,700 £1,700 – £2,300 £2,300 – £3,100
House Extension £1,500 – £2,100 £2,100 – £2,700 £2,700 – £3,300
Kitchen Renovation £400 – £750 £750 – £1,200 £1,200 – £2,000
Bathroom Renovation £700 – £1,100 £1,100 – £1,700 £1,700 – £2,600
Basement Conversion £1,600 – £2,400 £3,000 – £4,300 £4,300 – £6,000
Full Refurbishment £450 – £750 £750 – £1,150 £1,150 – £1,800

Use your estimate to plan the next step

Use the calculator result as early planning guidance rather than a fixed quotation. A realistic budget depends on the property, scope, specification, structural work, services upgrades, access, planning or building-control risk and the finish level you want to achieve. The same headline estimate can mean different decisions for a house refurbishment, flat refurbishment, house extension or basement conversion, particularly where hidden fabric, drainage, party-wall matters or staged access affect sequencing and risk.

Hampstead Renovations can review the result with you, identify likely cost drivers and turn it into a practical brief for design, procurement and delivery. This helps separate essential works from optional upgrades before the budget is treated as a commitment. That review can also highlight where a phased scope, different specification level or earlier planning advice could change priorities before commitments are made. If your project includes a kitchen renovation, bathroom renovation or planning-sensitive work, we can explain what should be checked before drawings, specifications and contractor pricing are developed. For a project-specific review, contact the team with the property type, intended scope and any constraints you already know.

Renovation Cost FAQs

Answers to the most common questions about renovation costs in London.

This calculator provides a ballpark estimate based on current London guide rates. It is accurate to within approximately 15-20% for most straightforward projects. Actual costs depend on site-specific factors such as access, ground conditions, structural requirements and your exact specification choices. For a precise quote, we recommend booking a free site visit with our team.
The cost per square metre covers the core works for the chosen project and specification level before VAT. Professional fees, planning, building control and party wall matters are applied only where they are normally relevant, then shown separately in the full breakdown.
Basement conversions involve significant structural work including underpinning, waterproofing (tanking), soil excavation and removal, temporary structural support and specialist drainage. The engineering complexity, the need for party wall agreements with neighbours, and the London-specific challenges of working below the water table all contribute to higher costs compared to above-ground renovations.
Yes, but the base calculator already assumes London labour and material pricing. Prime Central London postcodes receive a modest logistics premium, while Hampstead, Highgate and similar inner premium areas receive a smaller uplift for access, parking and period-property complexity.
These estimates do not cover loose furniture, kitchen appliances (unless built-in), curtains and soft furnishings, garden landscaping, external decorations, or any specialist items like home cinema systems, wine cellars or swimming pools. Demolition of existing structures and asbestos removal, if needed, would also be additional costs assessed during a site survey.
The specification level primarily affects materials and fixtures. Standard uses quality but widely available materials — good ceramic tiles, laminate worktops, standard sanitaryware. Premium steps up to engineered hardwood flooring, natural stone worktops, designer taps and better insulation. Luxury means bespoke joinery, Carrara or book-matched marble, underfloor heating throughout, smart home automation and architect-specified fixtures from premium European brands.
Timelines vary by project type: a bathroom renovation typically takes 3-4 weeks, a kitchen 4-6 weeks, a loft conversion 8-12 weeks, an extension 10-16 weeks, a basement conversion 16-24 weeks, and a full refurbishment 12-20 weeks. These are on-site construction times; add 6-12 weeks for design and planning beforehand. Our project managers provide a detailed programme during the quotation stage.
It depends on your project and property. Many loft conversions and single-storey rear extensions fall under Permitted Development rights and do not need a formal planning application. However, properties in conservation areas, listed buildings, flats and some larger projects will require planning permission. Basement conversions in several London boroughs now require planning approval. Our team can advise on the specific requirements for your project during a free consultation.
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