House Extension Services in Westminster

Professional House Extension Solutions for Westminster Residents

Free Site Visit

Fast Turnaround

Local Westminster Expertise

High Planning Approval Rate

Professional House Extensions in Westminster

Looking for professional house extension services in Westminster? Our experienced team of qualified architects provides comprehensive design solutions for residential projects across Westminster and the surrounding Enfield area. With deep local knowledge of Westminster's planning policies, building regulations, and architectural heritage, we deliver innovative designs that respect local character while meeting modern requirements.

House extension project near Westminster

A recent extension project in the Westminster area

Local Expertise

Our Westminster expertise is built on years of successful project delivery across the Enfield catchment area. We understand the local context, from conservation considerations to development opportunities, helping you make informed decisions about your house extension project. Our established relationships with local authorities and contractors ensure smooth project progression from initial design through to completion.

Planning & Regulations

Our Westminster team ensures your house extension project complies with all current planning policies and building regulations. We understand Enfield Council's specific requirements and can advise on the most appropriate approach for your project. From permitted development rights to full planning applications, we provide comprehensive support to ensure regulatory compliance while maximizing your development potential.

Property Types We Work With in Westminster

Westminster has a diverse housing stock and we have experience extending all property types in the area. Our architects adapt designs to suit the character and structure of each home, whether that means matching original brickwork on a period property or creating a contemporary contrast on a more modern home.

Victorian terraces

Edwardian semis

post-war council houses

1930s semis

modern townhouses

period conversions

Free Quote for Westminster

Tell us about your project and get expert advice within 24 hours.

Get a Free Quote Call 020 3051 9430

Mon–Fri: 9am–5pm

Free site visit & consultation

No obligation quote

Covering SW1 & surrounding postcodes

House Extension Costs in Westminster (2026)

Guide prices for house extensions in the Westminster area. Every project is different — we provide a detailed, itemised quote after a free site visit.

Extension Type	Typical Cost	Build Time	Planning
Single Storey Rear Extension	£35k – £70k	3–4 months	Usually PD
Double Storey Extension	£55k – £120k	5–7 months	Full application
Side Return Extension	£25k – £50k	2–3 months	Usually PD
Wrap-Around Extension	£60k – £130k	4–6 months	Full application
Loft Conversion (Dormer)	£40k – £65k	6–8 weeks	Usually PD
Kitchen Extension	£30k – £60k	3–4 months	Usually PD
Basement Conversion	£80k – £200k	4–8 months	Full application
Garage Conversion	£15k – £30k	4–6 weeks	Usually PD

Prices are guide figures for 2026 based on projects in the Greater London area. PD = Permitted Development (no formal planning application needed in most cases). Actual costs depend on specification, site conditions, and scope.

Our Extension Services in Westminster

Single Storey Extensions

Professional single storey extension design and planning for ground floor expansions

Typical: 6-12 weeks

Double Storey Extensions

Two-storey home extension design maximizing space and value

Typical: 8-16 weeks

Rear Extensions

Garden-facing extensions creating seamless indoor-outdoor living

Typical: 6-10 weeks

Side Extensions

Narrow extensions utilizing side garden space efficiently

Typical: 6-12 weeks

Kitchen Extensions

Specialized kitchen and dining space extensions for modern living

Typical: 8-14 weeks

Loft Conversions

Converting attic space into valuable living areas

Typical: 6-10 weeks

Basement Extensions

Underground extensions creating additional living space

Typical: 12-20 weeks

Planning Permission Services

Expert guidance through planning applications and permitted development

Typical: 8-16 weeks

Wrap Around Extensions

Comprehensive extensions combining rear and side elements for maximum space

Typical: 10-18 weeks

House Refurbishments

Comprehensive whole-house renovation and modernization services

Typical: 12-24 weeks

Structural Alterations

Expert structural engineering services including underpinning and load-bearing work

Typical: 8-16 weeks

Garage Conversions

Converting garages into functional living spaces for bedrooms, offices, and studios

Typical: 4-8 weeks

How Your Westminster Extension Project Works

From the first phone call to moving into your new space — here is what to expect at every stage.

Step 1

Free Consultation

We visit your Westminster property, discuss your vision, assess feasibility, and give you honest guidance on costs and planning routes.

Step 2

Design & Drawings

Our architects create detailed plans, 3D visuals, and construction drawings tailored to your Westminster home and how you want to live in it.

Step 3

Planning & Approvals

We prepare and submit your planning application, liaise with the local authority covering Westminster, and handle building regulations documentation.

Step 4

Construction

Our vetted builders bring the design to life. We oversee the build, conduct regular site visits, and manage quality at every stage.

Step 5

Completion & Sign-Off

Final inspections, building control sign-off, snagging checks, and handover — your new Westminster space is ready to enjoy.

House Extension Services

Specializing in residential extensions across Westminster, we provide tailored design solutions for every type of project. Our services include architectural design, planning applications, building regulations compliance, and construction drawings. We work closely with homeowners to create extensions that enhance their living space while maintaining the character and value of their property.

Planning Permission

Whether your Westminster project requires planning permission or falls under permitted development rights, our team provides expert guidance and support. We understand Enfield Council's specific requirements and can advise on the most appropriate approach for your extension project. Our comprehensive planning services ensure your project progresses smoothly through the approval process.

Completed house extension in Westminster area

Extension completed in the Westminster area

Building Control

Our Westminster building control services include detailed construction drawings, structural calculations, fire safety assessments, and accessibility compliance reviews. We understand the specific building control requirements for extensions in the Enfield area and can advise on structural solutions, thermal performance standards, and sustainability requirements.

Why Choose Us in Westminster

Choosing the right architect for your Westminster project is crucial for success. Our team offers a combination of professional expertise, local knowledge, and personal service that sets us apart from other architectural practices. We provide comprehensive extension services with a focus on quality, efficiency, and client satisfaction.

Helpful Guides for Your Westminster Extension

Loft Conversions in London: The Complete 2026 Guide to Costs, Planning & Design

Everything you need to know about loft conversions in London in 2026. Dormer, hip-to-gable, mansard and L-shaped options explained with costs, timelines and planning permission guidance.

Kitchen Extensions in London: Ideas, Costs & Planning Permission Guide 2026

Plan your dream kitchen extension in London. Explore side-return, rear and wrap-around options with 2026 costs, planning tips and design inspiration for every budget.

House Extension Costs London 2026: Area-by-Area Price Guide

Updated 2026 price guide for house extensions across London. Costs for single storey, double storey, loft conversions and more — broken down by area and project type.

Frequently Asked Questions About House Extensions in Westminster

How much does a house extension cost in Westminster?+

House extension costs in Westminster vary by type and size. Single storey rear extensions typically range from £35k – £70k, double storey extensions from £55k – £120k, and loft conversions from £40k – £65k. These are guide prices for 2026 — we provide an accurate, itemised quote after a free site visit to your Westminster property.

Do I need planning permission for a house extension in Westminster?+

Many extensions in Westminster can be built under permitted development rights without a formal planning application. This typically covers single storey rear extensions up to certain size limits. However, if your property is in a conservation area, is a listed building, or if the extension exceeds permitted development limits, a full planning application is needed. During our free consultation we assess your Westminster property and advise on the best route — and handle the entire application if needed.

What types of house extensions can you build in Westminster?+

We design and build all types of extensions in Westminster: single storey rear extensions, double storey extensions, side return extensions, wrap-around extensions, loft conversions (dormer, hip-to-gable, mansard), garage conversions, basement conversions, and kitchen extensions. Westminster has a mix of Victorian terraces, Edwardian semis, post-war council houses — we tailor every design to the specific property type.

How long does a house extension take in Westminster?+

Timelines vary by project: a single storey extension typically takes 3–4 months on site, a double storey 5–7 months, and a loft conversion 6–8 weeks. Before construction, the design and planning stage usually takes 8–12 weeks. We map out a detailed programme during your free consultation so you know exactly what to expect.

Do you handle planning applications with Westminster council?+

Yes — we have extensive experience submitting planning applications to the local authority covering Westminster. We prepare all drawings, design & access statements, and supporting documents, then manage communication with planning officers through to decision. Our knowledge of local policies helps avoid unnecessary delays or objections.

What areas near Westminster do you cover?+

We cover Westminster and all surrounding areas within a 20-mile radius. This means we can handle projects across the wider Westminster area, with the same level of local knowledge and expertise you'd get from a firm based in Westminster itself.

Ready to Start Your Westminster Extension?

Transform your Westminster home with our professional extension services. Contact us today for a free consultation and discover how we can help you create the perfect extension for your property. Our experienced team combines local knowledge with innovative design to deliver exceptional results that enhance your home's value and living space.

Get a Free Quote Call 020 3051 9430