Building Costs in Hampshire 2026: Extensions, Loft Conversions & New Build Prices

Hampshire is one of the UK's most economically successful counties — and that success is reflected in its construction costs. A strong jobs market, proximity to London, the presence of major employers like the MOD and marine industry, and the constraint of the South Downs National Park all combine to push building costs 5–15% above the national average.

For homeowners and developers, understanding Hampshire's unique construction market is essential to getting an accurate budget. Whether you're planning an extension in Winchester, a loft conversion in Southampton, or a new build development in Basingstoke, the numbers in Hampshire are different from the national averages.

This guide provides real 2026 cost data for Hampshire, based on live project estimates from Page Building Consultants.

Hampshire Extension Costs 2026

Extension costs in Hampshire vary by location, with a clear North-South gradient and a Winchester premium. The county's diverse housing stock — from Southampton Victorian terraces to New Forest cottages to Winchester Georgian townhouses — means extension approaches and costs vary significantly.

• Single-storey rear extension (3m x 4m): £26,000–£42,000
• Single-storey rear extension (4m x 6m): £30,000–£58,000
• Double-storey rear extension: £54,000–£98,000
• Single-storey side extension: £28,000–£48,000
• Wrap-around extension: £74,000–£142,000
• Garage conversion: £15,000–£32,000
• Orangery or garden room: £24,000–£62,000

Hampshire Loft Conversion Costs 2026

Loft conversions are consistently popular across Hampshire, driven by high property values that make extending up more cost-effective than moving. The county's housing stock — with significant numbers of Victorian and Edwardian properties in the cities and larger towns — provides excellent loft conversion potential.

• Velux / Rooflight conversion: £26,000–£40,000
• Dormer conversion (single, rear): £38,000–£58,000
• Dormer conversion (full-width): £44,000–£68,000
• Hip-to-gable conversion: £52,000–£78,000
• Mansard conversion: £60,000–£95,000

New Build Costs in Hampshire

Land costs in Hampshire are among the highest outside London and the immediate South East. Development land in Winchester or the M27 corridor can cost £1.2–2 million per acre, fundamentally shaping what types of development are viable.

• Standard specification: £1,650–£2,600/m²
• Mid-range specification: £2,500–£3,400/m²
• High specification: £3,200–£4,800+/m²

What's Driving Hampshire Building Costs in 2026?

Hampshire's construction market is shaped by a unique combination of factors.

• MOD and defence presence: Portsmouth Naval Base, Army bases around Aldershot and Basingstoke, and defence contractors create steady construction demand
• Marine and maritime industry: Southampton's port and marine sector drives specialist construction demand
• South Downs National Park: Restricts development across a significant portion of the county, pushing demand into remaining areas
• London proximity: Hampshire's excellent rail connections mean the county competes with London for skilled labour
• University cities: Southampton and Winchester have large student populations driving demand for HMOs and rental property renovations
• New Forest constraints: Building in or near the New Forest involves additional planning complexity and cost
• Affluent demographic: High household incomes across much of Hampshire mean clients often specify higher-specification finishes, pushing average project costs up

Hampshire Town-by-Town Cost Comparison

Using a single-storey rear extension (4m x 6m) as the benchmark, here's how costs compare across Hampshire in 2026.

• Winchester: £34,000–£62,000 — most expensive in Hampshire
• Southampton: £30,000–£55,000 — competitive for a major South Coast city
• Portsmouth: £29,000–£53,000 — similar to Southampton, competitive
• Basingstoke: £28,000–£52,000 — good value in North Hampshire
• Farnborough / Aldershot: £30,000–£55,000 — Surrey border premium
• Andover: £26,000–£48,000 — most affordable among Hampshire towns
• New Forest villages: £32,000–£60,000 — planning constraints add cost

Get an Accurate Hampshire Building Estimate

Page Building Consultants provides professional construction estimates across all of Hampshire, from Southampton and Portsmouth to Winchester, Basingstoke, and the New Forest. Our estimates account for Hampshire's specific labour market, material supply chains, and planning environment.

We can produce a detailed Hampshire-specific estimate within 24 hours of receiving your drawings. Call us on 0800 688 9321 or submit your plans online.