Prohaus guides

Plain answers before you build

Costs, planning rules and practical advice for extensions, loft conversions and renovations in Kingston, Surbiton, Richmond, Barnes, Putney, Fulham, Chelsea, Clapham and Wimbledon. Written from the projects we build, with official sources linked.

Real guide pricesProhaus starting figures, plus VAT, and what moves them up or down.

Official rules, sourcedPermitted development, building regulations and the Party Wall Act, linked to GOV.UK and the Planning Portal.

Local to south-west LondonThe councils, house types and conservation areas in the areas we work.
Latest guides

Start with the question you have

Single-storey rear extension in London stock brick with slim-framed sliding doors, Staunton Road, KingstonCosts

How Much Does a House Extension Cost in South-West London in 2026?

What a house extension costs in Kingston, Richmond, Putney and nearby in 2026: real guide prices, cost drivers, extra fees and how to keep your budget on track.

9 min readRead guide

Rear of a house with new full-width glazing and a stepped garden terrace, Park Way, WimbledonPlanning and rules

Do I Need Planning Permission for an Extension? A Council-by-Council Guide for South-West London

Permitted development limits, prior approval and the council for Kingston, Richmond, Putney, Fulham, Chelsea, Clapham and Wimbledon, explained simply with official sources.

8 min readRead guide

Loft conversion double bedroom with rooflights and a built-in desk, Grange Road, ChessingtonCosts

Loft Conversion Types and Costs: Dormer, Hip-to-Gable, Mansard or Rooflight?

Dormer, hip-to-gable, mansard or rooflight? Compare loft conversion types, costs from £50,000 plus VAT, planning rules and head height for south-west London homes.

8 min readRead guide

Rear of a renovated house with full-width glazing and a stone terrace, Upper Richmond Road, PutneyLocal guides

How to Choose a Builder in Kingston upon Thames: 12 Questions to Ask Before You Sign

12 questions to ask before you hire a builder in Kingston, Surbiton or south-west London: quotes, contracts, insurance, certificates, payments and guarantees explained.

7 min readRead guide

Brick extension with slim black-framed sliding doors opening onto a paved garden, Denmark Road, WimbledonPeriod homes and design

Side Return Extensions for Victorian Terraces: A Practical Guide for Fulham, Clapham and Putney

How a side return extension works on a Victorian terrace: planning, party walls, light, drainage, structure and cost from £60,000 plus VAT, with tips for south-west London.

7 min readRead guide

Open-plan kitchen with an island and sliding doors to the garden in a rear extension, Montolieu Gardens, PutneyCosts

Kitchen and Bathroom Renovation Costs in South-West London: What You Pay For

What a kitchen or bathroom renovation costs in Kingston, Putney and Richmond: guide prices from £4,500 plus VAT, the biggest cost drivers and the rules that apply.

6 min readRead guide

Single-storey rear extension with slim sliding doors and a new lawn, Montolieu Gardens, PutneyPlanning and rules

The Party Wall Act Explained: Notices, Timescales and Costs for London Extensions

When you need a party wall notice for an extension or loft conversion in London, the 1 and 2 month notice periods, the 3 m and 6 m rules, and who pays the surveyors.

7 min readRead guide

Vaulted dining space lit by rooflights inside a rear extension, Staunton Road, KingstonLocal guides

Extending a House in Surbiton and Kingston: Local Planning, House Types and Recent Projects

Extending a house in Surbiton or Kingston upon Thames: local house types, conservation areas, Kingston Council planning, costs from £60,000 plus VAT and recent Prohaus projects.

5 min readRead guide

White timber-framed glazed doors and windows on a brick period housePlanning and rules

Building Work in a Conservation Area: What Homeowners in Richmond, Barnes, Kingston and Chelsea Need to Know

Which extensions, lofts, windows and outbuildings need permission in a conservation area, how Article 4 directions work, and how to get approval in south-west London.

7 min readRead guide

Side view of a single-storey extension with sliding doors and stone steps, Barnfield Avenue, KingstonPlanning and rules

Prior Approval for Larger Rear Extensions: The 6 Metre and 8 Metre Rule Explained

How the prior approval route lets you build a single-storey rear extension up to 6 m (8 m detached) without full planning permission: rules, process, timescale and pitfalls.

5 min readRead guide

Brick garden office with black-framed glazed doors at the end of a garden, Maple Road, SurbitonPlanning and rules

Garden Offices: Planning Rules, Building Regulations and What to Ask Before You Build

Do you need planning permission or building regulations for a garden office in London? Height limits, the 15 and 30 square metre rules, power, foundations and what to ask a builder.

7 min readRead guide

Single-storey wrap-around extension with anthracite sliding doors and a raised terrace, Barnfield Avenue, KingstonCosts

Extend or Move? The Real Cost Comparison for South-West London Homeowners

Should you extend or move in south-west London? Compare stamp duty, agent and legal fees with extension and loft conversion costs, with worked examples and a decision checklist.

6 min readRead guide

Renovated bedroom with a white timber window, Mysore Road, ClaphamPeriod homes and design

Timber Sash Windows: Repair, Upgrade or Replace? A Guide for Period Homes

How to decide between repairing, upgrading or replacing timber sash windows in a period home, with conservation area rules, double glazing options and building regulations.

6 min readRead guide

Open-plan kitchen and dining room lit by rooflights, Barnfield Avenue, KingstonLocal guides

Renovating a 1930s Semi: Extensions, Lofts and Layouts that Work in Tolworth, Berrylands and Chessington

How to extend and renovate a 1930s semi in Tolworth, Berrylands, Chessington and New Malden: hip-to-gable lofts, wrap-around extensions, layouts, planning and costs.

6 min readRead guide

House exterior during building work, with new glazing and site hoarding, Florian Road, PutneyPlanning and rules

Planning Permission vs Building Regulations: What Is the Difference?

Planning permission decides whether you can build; building regulations decide how it is built safely. What each covers, when you need one or both, and who approves them.

5 min readRead guide

Rear extension with glazing installed and the terrace being finished, Montolieu Gardens, PutneyProcess

How Long Does a House Extension Take? A Week-by-Week Timeline

A realistic timeline for a single-storey rear extension in London: design, planning, party wall notices, then about 10 to 14 weeks on site, with a week-by-week example programme.

5 min readRead guide

New timber staircase and hallway, Florian Road, PutneyPlanning and rules

Loft Conversion Building Regulations: Fire Safety, Stairs, Insulation and Head Height

The building regulations every loft conversion must meet: structure, fire escape, fire doors, smoke alarms, stair headroom, insulation and ventilation, explained for London homeowners.

6 min readRead guide

Loft living room with a vaulted ceiling and steel-framed glazed doorsLocal guides

Loft Conversions in Wimbledon and Putney: House Types, Planning and Costs

Loft conversions in Wimbledon (Merton) and Putney (Wandsworth): which loft suits each house type, conservation areas to check, planning routes and costs from £50,000 plus VAT.

5 min readRead guide

Kitchen and dining space under a flat rooflight, Montolieu Gardens, PutneyPeriod homes and design

Open-Plan Kitchen Extensions: Light, Layout and Structure

How to plan an open-plan kitchen extension in a London home: layouts, islands, light, steel, heating, acoustics and fire safety, with real Prohaus projects and costs.

5 min readRead guide

Renovated house seen from the garden, Upper Richmond Road, PutneyCosts

What Does a Whole-House Renovation Cost? Budgeting a Period Home Refurbishment

What a whole-house renovation costs in south-west London, from £100,000 plus VAT at Prohaus: what is included, cost drivers for period homes, the order of work and how to budget.

5 min readRead guide

Building work in progress with a temporary steel stair and exposed structure, Florian Road, PutneyCosts

Hidden Costs of Building Work: 12 Items Missing from Cheap Quotes

The 12 costs most often left out of extension and renovation quotes in London, from party wall surveyors to skip permits, and how to spot them before you sign.

5 min readRead guide

New staircase with oak treads, handrail and slatted screenProcess

What a Good Building Quote Looks Like: Itemised vs Lump Sum

How to read a builder's quote for an extension or renovation: itemised vs lump sum, provisional sums, exclusions, payment stages and variations, with a comparison checklist.

4 min readRead guide

Living room with tall windows and built-in lit shelving, Mysore Road, ClaphamPlanning and rules

Article 4 Directions in Fulham and Chelsea: What They Mean for Your Windows, Roof and Extension

What Article 4 directions mean for windows, doors, roofs, boundary walls and basements in Fulham and Chelsea, how to check your street, and how to get approval.

6 min readRead guide

Garden office with wall lights on at dusk, Maple Road, SurbitonPlanning and rules

Lawful Development Certificates: When You Need One and Why Buyers Ask for It

What a Lawful Development Certificate is, when to get one for a permitted development extension, loft or garden office, how to apply, and why buyers' solicitors ask for it.

5 min readRead guide

Slim-framed aluminium sliding doors across a rear extension, Montolieu Gardens, PutneyPeriod homes and design

Aluminium vs Timber vs uPVC: Choosing Doors and Windows for an Extension

Compare aluminium, timber and uPVC for sliding doors, bi-folds and windows in a London extension: sightlines, insulation, maintenance, conservation areas and building regulations.

5 min readRead guide

Painted staircase and landing lit by a rooflight in a sloping ceilingPeriod homes and design

Rooflights and Glass Roofs in Extensions: What Works in London Terraces

Flat rooflights, lanterns, pitched roof windows and glass roofs for London extensions and side returns: light, heat, condensation, planning and building regulations explained.

5 min readRead guide

Floor-to-ceiling bespoke shelving wrapping the corner of a roomCosts

Bespoke Joinery Costs: Fitted Wardrobes, Alcove Units and Staircases

What bespoke joinery costs in south-west London, from £1,200 plus VAT at Prohaus: fitted wardrobes, alcove units, media walls, window seats and staircases, and what affects price.

4 min readRead guide

Painted alcove cupboard with floating shelves beside a chimney breastPeriod homes and design

Bespoke Storage for Victorian and Edwardian Homes: Alcoves, Eaves and Under-Stairs

Bespoke storage ideas for Victorian and Edwardian homes: alcove units, fitted wardrobes in chimney recesses, eaves storage in lofts, window seats and under-stairs drawers.

4 min readRead guide

Green shaker kitchen opening onto a long room with parquet flooringProcess

Can You Live at Home During an Extension or Loft Conversion?

What it is really like to live at home during an extension, loft conversion or renovation, when moving out makes sense, and how to set up a temporary kitchen and stay safe.

4 min readRead guide

Ground-screw foundations being installed for a garden office, Maple Road, SurbitonProcess

Preparing Your Home and Neighbours for Building Work: A Checklist

A practical checklist before an extension, loft or renovation starts: neighbours, party wall notices, permits, insurance, asbestos, clearing rooms, parking and working hours.

5 min readRead guide

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