Thinking about a side-return extension in Winchester? If you live in St Giles Hill, Hyde, Cathedral Close, Fulflood or St Cross, conservation rules will shape what’s possible. Here’s a quick, homeowner-friendly guide for 2025.

At-a-glance checklist (for quick approval)

• Location check: Confirm if your home is in a conservation area or listed (Winchester City Council maps).
• Scale & massing: Keep additions subservient to the host house; avoid over-dominance on the street scene.
• Materials: Use matching brick, clay tiles/slates, lime mortars where appropriate; avoid visually jarring cladding.
• Roofs: Modest pitched or discreet flat roofs with neat parapets; avoid bulky forms visible from the street.
• Openings: Slimline glazing; align head/ cill heights with existing windows; limit visible rooflights fronting the highway.
• Boundaries: Respect shared walls; avoid guttering over neighbours’ land; consider Party Wall procedures.
• Daylight/privacy: Demonstrate that outlook, daylight, and privacy for neighbours are protected.
• Drainage/services: Show rainwater management (soakaways) and unobtrusive flues/vents.
• Sustainability: Add fabric-first upgrades (insulation, airtightness) and low-carbon heating readiness.

What typically needs permission (2025)

In Winchester conservation areas, side-returns usually require planning permission. Permitted Development rights are often restricted by Article 4 Directions and heritage context. Listed buildings need Listed Building Consent for works affecting character.

Design moves that win support

• Step the extension down and back from primary façades.
• Use matching brick bonds and scaled brick specials for lintels.
• Introduce slim rooflights tucked behind parapets.
• Consider conservation-grade aluminium for discreet, thermally efficient frames.

Common pitfalls (and easy fixes)

• Over-glazing to the side boundary → add clerestory glazing or obscure glass above 1.7 m.
• Boxy massing → break with a set-back, parapet, or green roof edge.
• Service clutter → plan hidden external services screens.

Timeline & next steps

• Pre-app advice: 2–4 weeks
• Planning decision: ~8 weeks
• Building Regulations & tender: 3–6 weeks
• Build (typical single-storey): 8–12 weeks

Pro tip: Ask a Winchester-based architect to run a quick heritage/design statement and sunlight assessment to de-risk the application.

Common Questions We Are Asked:

• Can I use zinc or timber cladding? Sometimes to the rear/side, if low-visibility and high quality.
• Do I need a daylight study? Often helpful on tight plots to address neighbour amenity