How much does a home extension cost in Hertfordshire in 2025?

Typical single-storey extensions range from £50,000–£90,000 including VAT, fees and fittings. Our free consultation provides a personalised feasibility budget.

Do most home extensions need planning permission in St Albans, Watford or Hemel Hempstead?

Many single-storey rear extensions qualify under Permitted Development, especially up to 6-8m. We assess your property free of charge.

How long does a full home extension project take?

From initial consultation to completion typically 6–12 months, depending on design complexity and planning route. Our dedicated manager keeps everything on schedule.

Will I have one point of contact throughout the project?

Yes — you’ll have a dedicated project manager from feasibility through to handover for clear communication and peace of mind.

Do you cover my area in Hertfordshire?

We serve St Albans, Hemel Hempstead, Watford, Enfield and Harrow with our complete design, planning and build service.

Complete Home Extension Services Across Hertfordshire

We design, approve, and build home extensions for families across St Albans, Hemel Hempstead, Watford, Harrow, and Enfield.With 30 years of local experience, one dedicated team manages your entire project – from initial consultation and architectural design through council planning approval to final construction. No handoffs, no hidden costs, just a trusted partnership that delivers beautiful, practical extensions on time and on budget.

Why Hertfordshire Homeowners Trust Us

100%
Planning Approval Success Rate
(3+ years running)

One
Dedicated Project Manager
From concept to handover

30+
Years Local Experience
Hertfordshire specialists

5
Local Areas Covered
St Albans • Watford • Hemel • Harrow • Enfield

“Clear from beginning to end, thank you for great communications and an excellent room.”

— Peter, St Albans (2024 single-storey rear extension)

A Complete Extension Service You Can Trust

One Team, Start to Finish

From initial design to final build, you work with the same dedicated team - no handoffs, no confusion, just consistent quality and clear communication.

Design That Works for You

Thoughtful layouts that respect your home's character while maximizing space, light, and long-term value.

100% Planning Approval

We navigate council requirements, building regulations, and local constraints - securing approvals without delays or costly resubmissions.

On-Time, On-Budget Builds

Professional project management keeps your extension moving efficiently, with trades coordinated, quality assured, and you fully informed.

Recent Extensions Across Hertfordshire

Single-storey rear extension example in St Albans

Single Storey Rear Extension Creating a Light-Filled Family Space
Transformed a mid-terrace home with an open-plan kitchen-dining space and garden connection.

Loft Conversion with Rear Box Dormer Creating a Compliant Bedroom
Upgraded a non-compliant loft into a safe, habitable bedroom meeting all Building Regulations.

Single garage conversion example in Hatfield

Single Garage Conversion into Home Office & Guest Suite
Created versatile work-from-home and guest accommodation within an existing single garage structure.

View other our completed projects →

Our complete home extension service covers key Hertfordshire areas including St Albans, Hemel Hempstead, Watford, Enfield and Harrow.

Serving Hertfordshire Homeowners

HomeExtensionsRUs provides professional home extension design, approval and build services across Hertfordshire and surrounding areas. The interactive map above highlights our full coverage area, including St Albans, Hemel Hempstead, Enfield, Watford, and Harrow.

If you live within or near these locations, we offer start-to-finish support for rear extensions, double-storey extensions, kitchen expansions, loft conversions, and complete home transformations.

Start Your Free & Personalised Extension Journey Today

Book your free consultation today and get expert guidance tailored to your home and objectives.

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