Key Takeaway
A complete guide to loft conversions in Hampshire — dormer, Velux and hip-to-gable options, what they cost, when you need planning permission, and what's changed in 2026.
Loft conversions remain one of the most popular home improvements across Hampshire. They add a bedroom, bathroom and usable floor space without touching the garden, and they typically add more value than they cost to build. But there's significant variation in what's possible depending on your roof type, your property's planning position and your budget. This guide covers the key decisions for Hampshire homeowners in 2026.
The Three Main Loft Conversion Types in Hampshire
Velux / roof light conversions: The simplest and cheapest option. Roof lights are installed in the existing roof slope — no structural changes to the roof outline, no planning permission required in most cases. The limitation is head height: you need at least 2.2–2.4m of existing head height in the loft for a Velux conversion to produce a usable room. Many Hampshire 1930s semis and Victorian terraces have sufficient pitch; 1960s–70s bungalows typically don't.
Rear dormer conversions: A dormer extends the rear roof slope to create a full-height room with a vertical rear wall. Rear dormers are Permitted Development on most Hampshire houses as long as they don't exceed the permitted volume limits and don't face the principal elevation. They dramatically increase the usable floor space compared to a Velux-only conversion and are usually the best value choice on semi-detached and terraced properties.
Hip-to-gable conversions: Common on the many hipped-roof detached houses built across Hampshire from the 1960s to the 1990s — particularly in Basingstoke, Andover, Fareham and Southampton suburbs. The hipped end of the roof is rebuilt as a vertical gable, extending the ridge and adding 15–20m² of usable floor area. Hip-to-gable conversions always require planning permission as they change the roof outline.
Loft Conversion Costs in Hampshire: 2026
Build costs vary significantly by type and finish:
- Velux / roof light conversion: £25,000–£45,000
- Rear dormer with one bedroom and en-suite: £40,000–£65,000
- Hip-to-gable with rear dormer: £55,000–£90,000
- Full mansard conversion (less common in Hampshire): £70,000–£110,000+
These are build costs paid to your contractor. Hampshire Build design fees are separate and fixed: Pre-Build Package from £1,950 + VAT; Premium Plus from £4,950 + VAT.
Planning Permission for Hampshire Loft Conversions in 2026
Permitted Development Rights for loft conversions allow volume additions of 40m³ on semi-detached and terraced houses, and 50m³ on detached houses, without planning permission. Most rear dormers on average Hampshire properties fall within these limits. However, planning permission is required if:
- The property is in a conservation area (no dormer additions to any roof slope visible from a public highway)
- The property has previously used its PD loft allowance
- The conversion involves a hip-to-gable or mansard alteration
- The property is listed
The conservation area restriction is particularly significant around Winchester, parts of Southampton's historic areas, Alresford, Stockbridge and many Hampshire villages. We check your planning position at every complimentary consultation.
What's Changed in 2026
Planning application fees increased from April 2025 — loft conversion applications now cost £258 for householder applications in England. Building regulations fees vary by local authority. Hampshire Build's fixed design fee covers the planning application fee payment on your behalf — there are no surprise additional charges.
Hampshire Build serves all of Hampshire for loft conversions: Winchester, Southampton, Basingstoke, Andover, Fareham, Eastleigh, Romsey, Alton, Fleet, Farnborough and Petersfield. Book a complimentary consultation and we'll advise on the right loft conversion type and planning route for your specific property.
