Bromley Council planning guide: side space, Green Belt and what the December 2024 list asks of your drawings

Side space: the Bromley rule that shapes a two-storey extension

Bromley's Local Plan was adopted on 16 January 2019, and the council's own page says it is under review, so it is the plan your drawings are read against today. Our Bromley planning permission page covers drawings for applications in the borough.

Policy 8 (Side Space) says that for a proposal of two or more storeys the council will normally require “a minimum 1 metre space from the side boundary of the site should be retained for the full height and length of the building”. Where larger gaps already exist in a street, it expects a more generous space. The reason it gives is to prevent a cramped appearance and unrelated terracing, which is why a first-floor side extension that touches the boundary is the scheme most likely to meet resistance here.

Policy 6 (Residential Extensions) sets the other test. The “scale, form and materials of construction should respect or complement those of the host dwelling”, gaps between buildings that contribute to character should be kept, and dormers should be sited away from prominent roof pitches unless dormers are a feature of the area. The supporting text adds that flat-roofed side extensions of two or more storeys to traditional houses will normally be resisted. A dormer loft conversion and a side return extension are both drawn with these two policies in mind.

What Bromley's December 2024 list asks of the drawings

The council's planning validation page says the current list was published after agreement by its Development Control Committee on 12 December 2024. Part 1 applies to every application including householder ones. Drawings go in as separate single-page PDFs, floor plans, elevations and roof plans at 1:50 or 1:100, each with a unique drawing number and key dimensions marked.

Three details catch people out. Key dimensions must include the overall height of the proposed works, “not just the height to the eaves”. For elevations, “Both flank elevations are required for example a rear extension even if the property is semi-detached or terraced”. And photographs must be taken within 30 days of submission and show all sides of the house plus front and rear street scenes with the neighbouring properties. Streetscene elevations with heights in metres above ordnance datum are asked for when a proposal raises the height of the building.

Roof plans are needed for first-floor and two-storey extensions and for any work to the roof, and site sections where ground levels change. The list also asks that existing and proposed drawings show only that development and not other works, such as permitted development not yet built. Once an application is in, extra drawings go to planning.admin@bromley.gov.uk and not through the Planning Portal, and an invalid application carries an administration fee. Our planning drawings and house extension drawings are set out to these rules from the start.

Flood zones and drainage

Bromley splits flood paperwork by size. For householder and other minor extensions in Flood Zone 2 or 3 where the added footprint does not exceed 250 square metres, the list asks for a declaration on the Environment Agency's form rather than a full report. A flood risk assessment is asked for in Flood Zones 2, 3 or 3b, in areas with critical drainage problems, and where the council's Strategic Flood Risk Assessment shows increased risk.

A foul sewage and surface water drainage assessment is asked for where a scheme increases surface water runoff, which includes building on garden land. For a rear extension that is usually a short statement; for a new outbuilding with a large roof it can be more. A planning constraints report shows the flood zone, and a flood risk assessment answers the list item where the larger report is needed.

Building control and party wall

Planning permission is not building regulations approval. Bromley's building control service offers full plans approval, building notice approval for small domestic work, and a regularisation application for work done without approval, and says it is a member of Local Authority Building Control. Our building regulations reports guide sorts the reports by where your project stands, and the building regulations drawings page covers the set that goes to building control.

A shared wall brings in the Party Wall etc. Act 1996, which runs alongside planning and applies even where no permission is needed. Our party wall services guide explains the notices.

Other documents the list can ask for

The same list asks every applicant for the national Biodiversity Net Gain information or an exemption statement, and a CIL form. For the exemption route see biodiversity net gain and CIL form preparation. It asks for a construction logistics plan mainly for larger schemes and for a structural survey where a Green Belt building is being converted or a listed building altered substantially. A fire statement under London Plan Policy D12 is asked for with new dwellings and conversions, and our fire safety statement page covers it.