Do I need an architect for a house extension?

Not legally, but for anything beyond a small permitted development extension, an architect's drawings are usually needed for planning and building regulations. An architect also helps avoid costly design mistakes before building work starts.

How long does a house extension take from design to completion?

Design and planning typically take a few months. Build time depends on size and complexity, a single storey side return is far quicker than a two storey rebuild.

Can I extend without planning permission?

Many single storey rear and side return extensions qualify under permitted development. Larger extensions, wrap-arounds, and properties in conservation areas or listed buildings usually need a full application.

Do I need a party wall agreement for a house extension?

If your extension involves work on or near a shared wall or boundary with a neighbour, you'll usually need a party wall agreement under the Party Wall Act. We flag this early so it doesn't hold up the build once work is ready to start.

Does a house extension add value to my home?

A well-designed extension usually increases a property's value, though the actual return depends on the local market, the quality of the finish, and how well the new space suits the house.

Leading Architects in Wimbledon

Wimbledon Park is where Design United Studio is based, not just an area we say we cover. That means planning applications drafted with a working knowledge of Merton Council's requirements, and a site visit that doesn't involve a trip across London.

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Fewer Objections, Faster Approvals

The Local Track Record Behind Every Wimbledon Approval

Every planning authority has its own preferences, precedents and pinch points, and Merton is no exception. Knowing which extension depths, roof forms and material choices tend to get supported locally, versus which ones invite objection, comes from working in the borough repeatedly, not from a national planning database.

As architects in Wimbledon, we've built that local track record project by project, which is part of why our planning approval rate sits at 99%.

Working Within Wimbledon's Conservation Areas

Wimbledon Village and a number of surrounding streets sit within designated conservation areas, where the usual permitted development rights are often restricted or removed entirely.

We check a property's conservation status and any Article 4 directions before design work starts, so a scheme is shaped around what's actually achievable rather than redesigned later after a refusal.

One Local Team for Extensions, Lofts and Interiors

Wimbledon's housing stock, Victorian and Edwardian terraces, 1930s semis, mansion flats around the Village, tends to suit a small number of proven moves: a loft conversion for extra bedrooms, a rear or side return extension for kitchen and living space, or an interior remodel that makes better use of what's already there.

We handle loft conversions and interior design as part of the same service, so the structural design and the finished room work as one project rather than two separate briefs handed to different people.

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A Studio That Knows the Streets, Not Just the Borough

Being based in Wimbledon Park means we can walk a site, meet a neighbour, or attend a pre-application meeting without it becoming a logistical exercise.

That proximity shortens the feedback loop on a project considerably, particularly during the survey and design stages.

Planning Applications Built Around Merton's Validation Requirements

A surprising number of applications get delayed at the validation stage over missing documents or drawings that don't match the local checklist, not over the design itself. We prepare applications against Merton Council's specific requirements from the outset, so submission doesn't become the bottleneck.