Mark Eden
12 min read
Key Takeaway
Everything Hampshire homeowners need to know about single-storey extensions in 2025. Design ideas, costs, planning permission, and expert tips for Winchester, Basingstoke, and Southampton projects.
Single-Storey Extensions in Hampshire: The Complete 2025 Guide
Single-storey extensions are the most popular home improvement for Hampshire families in 2025. Whether you're in Winchester, Basingstoke, Southampton, or surrounding areas, a well-designed single-storey extension can transform your home. Here's everything you need to know.
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
- Design fee: £1,350-£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
- Design fee: £1,350+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
- 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
- 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
Hampshire Planning Success Rate
Our Winchester-based designers achieve 97% planning approval rate because we understand local Hampshire council preferences and planning policies.
Single-Storey Extension Costs in Hampshire 2025
Construction Costs per m²
- Basic spec: £1,800-£2,200/m² (brick, basic kitchen)
- Good spec: £2,200-£2,800/m² (bi-folds, quality kitchen)
- High spec: £2,800-£3,500/m² (premium materials, underfloor heating)
Total Project Costs (30m² Extension)
- Design fees: £1,350-£1,950+VAT (Hampshire Build packages)
- Planning fee: £528 (council fee if required, as of April 2025)
- Building regulations: £500-£800 (council fee)
- Construction: £54,000-£105,000 (30m² at £1,800-£3,500/m²)
- Total project: £56,000-£108,000
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: 2-3 weeks
- 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
- Complete service: Planning through to building regs
Hampshire Build's Single-Storey Extension Service
As Winchester-based extension designers, we've completed 300+ single-storey extensions across Hampshire:
- Local expertise: 20+ years designing in Hampshire
- Fixed-fee packages: From £1,350+VAT (no hourly billing)
- 97% planning success: We understand Hampshire councils
- Fast turnaround: Drawings in 2 weeks, not 8 weeks
- Complete service: Survey through to building regulations
Getting Started with Your Single-Storey Extension
Ready to transform your Hampshire home with a single-storey extension?
- Complimentary consultation: Discuss your vision and budget
- Feasibility assessment: Check planning and costs
- Choose package: Essential, Pre-Build, or Premium
- Design & drawings: 2-3 weeks to completion
- Planning submission: If required for your project
- Building regulations: Technical approval for construction
- Builder quotes: Get 2 quotes with our drawings
- Build: 8-14 weeks to your dream extension
Book your free feasibility call or view our fixed-fee packages to start your Winchester, Basingstoke, or Southampton single-storey extension journey.
