Single-Storey Extensions Hampshire: Complete 2026 Design Guide

Key Takeaway

Explore single-storey extension layouts, planning considerations and budgeting factors for Hampshire homes, with a free feasibility check for your project.

Single-Storey Extensions in Hampshire: The Complete 2026 Guide

Whether you're in Winchester, Basingstoke, Southampton, or surrounding areas, a well-designed single-storey extension can transform your home. This guide covers layout, planning and budgeting considerations.

Cost figures in this older guide are historical examples, not current or verified 2026 prices. Confirm contractor pricing and current statutory fees before budgeting; the free cost calculator can provide an initial project-specific estimate.

Why Single-Storey Extensions Are Perfect for Hampshire Homes

• Open-plan living: Create the modern kitchen-dining spaces Hampshire families want
• Garden connection: Bi-fold doors bring outdoor spaces into your home
• Natural light: Roof lights and glazing flood your home with brightness
• Property value: Add 15-20% to home value with quality extension
• Planning friendly: Many qualify for permitted development

Popular Single-Storey Extension Types in Hampshire

1. Rear Extension (Most Popular)

Perfect for creating open-plan kitchen-dining-living spaces:

• Typical size: 20-40m² (6m x 4m to 8m x 5m)
• Cost range: £45,000-£90,000 + VAT
• Design fee: £1,950 + VAT
• Planning: Often permitted development
• Popular in: Winchester, Southampton, Basingstoke suburbs

2. Side Return Extension

Ideal for Victorian/Edwardian terraced houses in Hampshire towns:

• Typical size: 12-25m² (fills narrow side passage)
• Cost range: £28,000-£55,000 + VAT
• Design fee: £1,950 + VAT
• Planning: Usually permitted development
• Popular in: Winchester, Southampton, Fareham terraced areas

3. Wrap-Around Extension

Combines rear and side return for maximum space:

• Typical size: 35-60m²
• Cost range: £70,000-£140,000 + VAT
• Design fee: £1,950-£2,950 + VAT
• Planning: Usually requires planning permission
• Popular in: Larger Hampshire properties

4. Kitchen Orangery Extension

Traditional Hampshire style with modern comfort:

• Typical size: 25-45m²
• Cost range: £55,000-£110,000 + VAT
• Design fee: £1,950-£2,950 + VAT
• Planning: May require planning in conservation areas
• Popular in: Winchester conservation area, period properties

Single-Storey Extension Design Ideas for Hampshire Homes

Open-Plan Kitchen-Diner

• 6m-8m rear extension creating 30-40m² space
• Bi-fold or sliding doors to garden
• Kitchen island for food prep and entertaining
• Dining area seating 8-10 people
• Roof lights for natural light

Family Kitchen Extension

• U-shaped or L-shaped extension 25-35m²
• Snug area with sofas for family time
• Homework station or desk space
• Large kitchen for family cooking
• French doors or bi-folds to garden

Garden Room Extension

• 4m-6m extension focusing on garden views
• Maximum glazing (bi-folds, roof lights, side windows)
• Minimal kitchen - more living/entertaining space
• Perfect for Hampshire garden lovers
• Underfloor heating for year-round use

Planning Permission for Hampshire Single-Storey Extensions

Permitted Development Rights

Many single-storey extensions in Hampshire don't need planning permission:

• Terraced/semi-detached: Up to 6m from rear wall
• Detached houses: Up to 8m from rear wall
• Maximum height: 4m (3m if within 2m of boundary)
• Eaves height: Maximum 3m
• Coverage: No more than 50% of garden covered

When Planning Permission IS Required

• Extensions exceeding permitted development limits
• Conservation areas (Winchester, Romsey, etc.)
• Listed buildings
• Designated areas (AONB, National Park)
• Previous extensions using up allowances

Single-Storey Extension Costs: Historical Examples

Construction Costs per m²

• Basic spec: £1,800-£2,200 + VAT/m² (brick, basic kitchen)
• Good spec: £2,200-£2,800 + VAT/m² (bi-folds, quality kitchen)
• High spec: £2,800-£3,500 + VAT/m² (premium materials, underfloor heating)

Total Project Costs (30m² Extension)

• Design fees: £1,950 + VAT (Hampshire Build packages)
• Planning fee: Check the current fee with the relevant local planning authority.
• Building regulations: the current published fee (council fee)
• Construction: £54,000-£105,000 + VAT (30m² at £1,800-£3,500 + VAT/m²)
• Total project: £56,000-£108,000 + VAT

Building Regulations for Hampshire Single-Storey Extensions

All single-storey extensions require building regulations approval covering:

• Foundations: Depth and design for Hampshire soil conditions
• Insulation: U-values for walls, roof, and floor
• Glazing: Energy efficiency of windows and doors
• Ventilation: Air flow and moisture control
• Drainage: Foul and surface water management
• Structural: Steel beam calculations and support

Timeline for Single-Storey Extensions in Hampshire

• Design phase: Survey and drawing schedule agreed after instruction
• Planning (if required): 8-12 weeks
• Building regulations: 4-6 weeks
• Builder quotes: 2-4 weeks
• Construction: 8-14 weeks
• Total timeline: 6-9 months from design to completion

What Makes a Great Single-Storey Extension in Hampshire?

Design Features Hampshire Families Love

• Bi-fold or sliding doors: 3-6m opening to garden
• Roof lights: 2-4 Velux windows for natural light
• Underfloor heating: Comfortable warmth, no radiators
• Kitchen island: Central prep and entertaining space
• Open-plan layout: Visual connection between kitchen-dining-living

Materials That Work Well in Hampshire

• Brick: Match existing house (red, buff, or Hampshire stock brick)
• Render: Modern finish or period-appropriate lime render
• Roof: Flat roof with lantern, or pitched to match existing
• Windows: Aluminum bi-folds (grey or anthracite popular)
• Flooring: Large-format tiles or engineered oak

Common Mistakes to Avoid

• Too small: Go for 6m+ depth for proper kitchen-diner
• Not enough light: Add roof lights even with bi-folds
• Poor heating: Underfloor heating is worth the investment
• Cheap windows: Quality bi-folds transform the space
• Ignoring orientation: South-facing needs shading solutions

Choosing an Extension Designer in Hampshire

Look for designers who understand:

• Hampshire planning: Each council has preferences
• Local building styles: Victorian, Edwardian, 1930s, modern
• Soil conditions: Clay, chalk, gravel affect foundations
• Fixed-fee pricing: Budget certainty vs hourly billing
• Defined design scope: Planning drawings and building regulation drawings prepared for Building Notice submission

Hampshire Build's Single-Storey Extension Service

As Winchester-based extension designers, we've completed 150+ extensions across Hampshire:

• Local expertise: 20+ years designing in Hampshire
• Fixed-fee packages: From £1,950 + VAT (no hourly billing)
• Clear scope: Drawings and approvals are set out against your agreed package
• Defined design scope: Measured survey and drawings for planning and Building Notice submission

Getting Started with Your Single-Storey Extension

Ready to transform your Hampshire home with a single-storey extension?

1. Complimentary consultation: Discuss your vision and budget
2. Complimentary consultation: Discuss the initial planning route and project scope based on information provided
3. Choose package: Pre-Build Package, Premium Package, or Premium Plus Package
4. Design & drawings: Delivered against the agreed project scope
5. Planning submission: If required for your project
6. Building regulations: Building regulation drawings prepared for Building Notice submission; Building Control determines compliance
7. Builder quotes: Use your package documents for contractor pricing, or choose Premium for tender support
8. Build: 8-14 weeks to your dream extension

Book a complimentary consultation or view our fixed-fee packages to discuss a Winchester, Basingstoke or Southampton single-storey extension.

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