Loft conversions, rear extensions, and side returns in BN3 — what permitted development covers, where conservation area rules apply, and what it typically costs.
Extending a Victorian or Edwardian house in Hove is one of the most common ways buyers add value and space to a period property. Most terraces and semis in BN3 have been extended in some form over the decades — but the rules around what you can do without planning permission, and what you can't, are worth understanding before you buy with extension plans in mind.
Permitted development (PD) rights allow certain extensions and alterations without needing to apply for planning permission. For a standard terraced or semi-detached house in Hove not in a conservation area, the headline allowances include:
PD rights are cumulative and based on the original house footprint (typically defined as how it was in 1948, or when built if later). Any extensions already done by previous owners count toward the limits.
In conservation areas, PD rights are significantly restricted. Parts of Hove — including most of Brunswick Town and some streets in Cliftonville and central Hove — fall within designated conservation areas. In these areas:
Check Brighton & Hove City Council's planning portal to confirm whether a specific property is in a conservation area before assuming any extension is straightforward. The portal also shows planning history for the property, which tells you what has already been done and approved.
Rear extension (single-storey): the most common extension in Hove terraces. Extends the kitchen or living space into the rear garden. A well-designed open-plan kitchen-diner is one of the most consistent ways to add value to a Hove terrace. Cost: roughly £1,500–£2,200/m² including structure, plumbing, and electrics, so a 15m² extension might cost £22,000–£33,000 before fitting out.
Loft conversion: adds a bedroom (often with en-suite) without losing garden. Dormer loft conversions are standard in Hove terraces. Cost: £40,000–£70,000 for a straightforward dormer, more for a full hip-to-gable conversion on a semi. Adding a bedroom typically adds more value than the cost in the current Hove market.
Side return extension: fills in the narrow side passage common in Victorian semi-detached and terraced properties. Usually combined with a rear extension to create an L-shaped ground floor. Cost: similar per-m² to a rear extension, but often higher because the narrow space complicates construction access.
Basement: feasible in some Hove properties but expensive and disruptive. Costs of £3,000–£5,000/m² are typical, and the process involves significant structural work and Party Wall considerations. Only worth considering if above-ground extension potential is exhausted.
Any extension work on or near a shared boundary — which is almost all work in a terrace — requires serving formal Party Wall notices on affected neighbours under the Party Wall etc. Act 1996. This is a legal obligation, not optional. Neighbours have 14 days to consent or dissent; if they dissent, a Party Wall surveyor (or surveyors) must be appointed. Build this into your timeline: from serving notices to starting work can take 6–8 weeks.
For anything beyond a very simple extension, using an architect or architectural designer adds cost but saves it more reliably than most things in a building project. A well-drawn set of plans reduces contractor pricing uncertainty, avoids problems during construction, and produces a better result. The RIBA Find an Architect service and local recommendations are the two most reliable routes to finding someone who knows Hove's planning environment.
Use our free valuation tool to get a sense of the current value range for the property type you're buying or extending — it helps calibrate whether a given extension budget makes financial sense in your street.
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