House Extension Architects UK — Design, Costs & How to Hire

What Does a House Extension Architect Do?

A house extension architect helps you plan, design, and deliver your home expansion project from concept to completion. They ensure your extension complements your existing home, enhances property value, and meets local planning rules.

• Concept and feasibility studies
• Measured surveys and existing drawings
• Extension design and 3D visualisation
• Planning permission and building regulations
• Coordination with builders and engineers

Types of House Extensions

Common house extension types in the UK include:

• Rear extensions — Extend your kitchen or living room space into the garden area.
• Side return extensions — Ideal for terraced or semi-detached homes, making use of narrow side alleys.
• Wraparound extensions — Combine rear and side extensions for maximum space and open-plan layouts.
• Double-storey extensions — Add extra bedrooms or bathrooms above a ground-floor extension.
• Loft and garage conversions — Optimise unused areas for home offices, studios, or guest rooms.

Average Costs of House Extension Architects UK

Architect fees for extensions depend on size, complexity, and location. On average:

• Small single-storey extension: £1,000 – £3,500
• Medium extension: £3,500 – £6,000
• Larger or double-storey extension: £6,000+

Many architects charge 5–10% of your total build cost, or offer fixed-price design packages. Some also provide hourly rates between £50–£120.

Do You Need Planning Permission for a House Extension?

Some smaller extensions fall under Permitted Development Rights — meaning no formal planning permission is required. However, you’ll still need to meet specific size, height, and boundary rules. Your architect can confirm this and prepare drawings for local council approval if required.

They’ll also ensure your extension meets UK building regulations for safety, insulation, drainage, and structural integrity.

How to Hire the Right House Extension Architect

• Choose a RIBA-registered or ARB-accredited architect.
• Review their portfolio of completed home extensions.
• Ask for references and previous client feedback.
• Agree on clear deliverables, costs, and timelines before work starts.

Through SCE Marketplace, you can post your extension project and receive free quotes from trusted local architects near you — saving time and money.

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Frequently Asked Questions (FAQs)

1. How long does a house extension design take?

Most architects take 2–6 weeks to complete design and planning, depending on complexity and council response times.

2. Can I get 3D designs of my extension?

Yes, many architects provide 3D renders or virtual walkthroughs to visualise your new space before construction begins.

3. Do I need an architect for a small extension?

While not legally required, hiring an architect ensures your design is efficient, compliant, and adds maximum value to your home.

4. How do I find local house extension architects?

Use SCE Marketplace to compare quotes from qualified architects across the UK — free and fast.

Final Thoughts

A well-planned extension can transform your home and boost its value. Partnering with the right house extension architect UK ensures your project runs smoothly from planning to completion. Start your journey with SCE Marketplace and receive no-obligation quotes today.

Post your house extension project on SCE Marketplace and connect with trusted architects across the UK — fast and free.