Roof Terraces and Balconies in Merton

Creating elevated outdoor space—whether cutting a terrace into a high roof pitch or placing a balcony on top of a single-story rear extension—is highly coveted across the London Borough of Merton. However, it is fundamentally the most difficult feature to push through the local planning system.

Merton planners view elevated outdoor space as an inherent threat to the privacy and quiet enjoyment of neighboring gardens.

The Privacy Algorithm

Any proposal for a roof terrace must proactively neutralize the threat of overlooking:

• No Permitted Development: Roof terraces and balconies are never Permitted Development. Even if you are building an otherwise entirely legal PD loft conversion, adding a structural balcony or establishing a usable roof terrace instantly forces the entire project into a Full Planning Application.
• The 18-Meter Face-to-Face Distance: Planners enforce rigid separation distances to protect privacy. If your proposed terrace allows a direct line of sight into the habitable room windows of the house behind you, and the distance is less than 18 to 21 meters, the terrace will be refused unless aggressive screening is deployed.
• The 'Screening' Dilemma: To prevent overlooking into the immediate adjoining neighbors' gardens, architects often propose 1.8m high opaque glass or timber privacy screens around the terrace perimeter. However, planners frequently veto the screens themselves, arguing that towering timber hoarding towering above a rear extension creates an ugly, overbearing visual mass that constitutes poor design.

Official Merton Council Resources

Before committing to any major architectural project, we strongly advise cross-referencing your ambition directly with the local authority. The following links provide direct access to Merton Council's live planning portals and heritage registries:

• Merton Planning & Building Control Portal
• Search Live Merton Planning Applications
• Merton Heritage, Conservation Areas & Article 4 Directions

How We Can Help

If you are considering a major refurbishment, extension or basement in Merton, our in-house architectural and construction teams are highly experienced with the specific constraints and policies of this council. Do not leave your planning application to chance—our Planning & Permissions and Architecture services are explicitly designed to handle strict London authorities from initial conceptual design through to final, legal consent.

Once permission is secured, our Refurbishment & Interiors division carefully manages the execution, guaranteeing the design integrity is maintained throughout the build phase.

*Published in the Hampstead Renovations Planning Guide Collection — delivering expert design and build strategies for London's most heavily guarded conservation boroughs.*