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Free 2026 London Planning ReportDouble Storey Extension Drawings in Bromley

Detached London brick house with garage and driveway, characteristic of Bromley's suburban plots
Bromley · London

Double Storey Extension Drawings in Bromley

Fixed-fee, MCIAT-chartered double storey extension drawings for Bromley homeowners — London Borough of Bromley validation and local constraints handled from the start.

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As London's largest borough by area, Bromley offers the generous interwar detached and semi-detached plots that make substantial rear and double-storey extensions genuinely viable. The housing stock runs from suburban semis around Beckenham, Penge and West Wickham to larger detached homes and edge-of-London properties toward Orpington, Hayes and Chislehurst. The right Bromley application is usually about maximising a large plot within policy rather than squeezing a tight terrace, and the room to build is exactly why so many owners here extend rather than move.

Two constraints shape what is achievable. Green-belt designation across the borough's outer edges restricts the scale of additions on properties toward Orpington and Chislehurst, where extensions are assessed against strict limits on disproportionate additions to the original dwelling. Conservation control in Chislehurst, Keston, Hayes, Park Langley and Bromley Town governs materials and design in those areas. Bromley has no borough-wide Article 4 direction affecting typical householder permitted development, so detached homes here often retain fuller rights than inner-London terraces, which we always check first.

We prepare Bromley planning drawings that use the available plot fully while respecting green-belt and conservation constraints, confirming permitted development limits for detached and semi-detached homes before we draw and evidencing green-belt cases carefully where they apply. Because the plots allow larger schemes, we design to the project rather than a standard template, and we agree a fixed fee up front, typically around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Bromley approves. The council determines most householder applications within the statutory eight-week period once validated, so a complete, correctly scaled, validation-first submission is the best way to hold that timescale.

Detached London brick house with garage and driveway, characteristic of Bromley's suburban plots
Isometric illustration of a Bromley home extension design
Proposed floor plan
Bromley

Planning in Bromley: what to know before you apply

Bromley has no borough-wide Article 4 direction affecting typical householder permitted development; the binding constraints are green-belt policy on outer properties and conservation-area control in Chislehurst, Keston and Bromley Town. Detached homes here often retain fuller permitted development rights than inner-London terraces.

Typical Bromley housing stock

Large interwar detached and semi-detached houses with generous plots, plus green-belt and edge-of-London properties toward Orpington and Chislehurst.

Areas we regularly draw for in Bromley

Bromley · Beckenham · Orpington · Chislehurst · Penge · Hayes · West Wickham

Double Storey Extension Drawings for Bromley homes: the package and the process

Every double storey extension drawings we prepare for a Bromley property is drawn to London Borough of Bromley’s validation standards and tuned to the local constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.

A double storey extension builds a second floor above a single-storey side or rear addition, typically adding a bedroom and bathroom upstairs over a widened kitchen or reception room below. Because the foundations and roof of a single-storey extension already carry most of the fixed cost of building, adding a floor on top is often the most cost-effective way to gain two rooms rather than two separate projects. The trade-off is scrutiny: a two-storey addition sits closer to eye level with neighbouring windows and gardens, so councils examine massing, roofline and boundary distance more closely than they would a single-storey extension.

DrawingsDirect draws double storey side and rear extensions for full planning and building regulations, with structural calculations for the additional floor load and foundations produced in-house by our MCIAT-chartered team, on a fixed fee. If a single storey is enough, see our Rear Extension and Side Return Extension pages, or combine both with a Wraparound if you are extending sideways as well as up.

Do I need planning permission for a double storey extension in London?

Almost always. Permitted development rights for two-storey extensions are far more restrictive than for single-storey work, particularly on how close the new structure can come to a boundary and how closely its roof pitch and eaves height must match the existing house, so most double storey projects are drawn and submitted as full householder planning applications rather than relying on permitted development.

Where the property sits in a conservation area or is subject to an Article 4 direction, any remaining permitted development allowance for a second storey is typically removed entirely, reinforcing the need for a full application. We check your property's status and your borough's design guidance before drawing.

How do councils control the impact of a double storey extension on neighbours?

Because a second storey introduces new windows and massing at first-floor level, London boroughs apply design guidance aimed specifically at protecting neighbouring light, privacy and outlook.

  • The 45-degree rule, tested at neighbouring windows, to check the extension does not block an unreasonable amount of daylight
  • A common design expectation that a two-storey side extension is set in roughly 1 metre from the shared boundary, rather than built hard against it
  • A first floor commonly set back from the ground floor front elevation, so the upper storey reads as subordinate to the main house from the street
  • Obscure or high-level glazing on flank walls facing directly into a neighbour's garden or windows, to limit overlooking
Extending once vs twice: single versus double storey
OptionWhat it addsTypical fee
Single-storey rear extensionA ground-floor kitchen-diner only, may qualify for permitted developmentsee Rear Extension Drawings, from £1,100
Double storey side or rear extensionTwo rooms across two floors, usually needs full planningFull Planning pack ~£1,600–£2,400
Double storey + Building Regulations (structural)Combined pack including structural calculations for two-floor loads and foundationsPlanning + Building Regs pack ~£2,200–£3,850
Wraparound (rear + side return)Combines two single-storey extensions into one L-shaped ground floorsee Wraparound Extension Drawings, from £2,200
FAQ

Double Storey Extension Drawings in Bromley — FAQs

How much does a double storey extension cost to design in London?+
Double storey extension drawings start from £2,400, covering full planning permission and structural design for the additional floor. A combined planning and building regulations package with full structural calculations runs up to around £3,850, fixed and agreed upfront.
Do I need planning permission to add a second storey?+
In almost all cases, yes. Permitted development rights for two-storey extensions are much tighter than for single-storey work, particularly around boundary distance and roof matching, so we design double storey projects on the assumption a full householder planning application is required.
Will a double storey extension overlook my neighbour's garden?+
That is exactly what planning officers check, using the 45-degree daylight rule alongside boundary set-in and first-floor set-back guidance. Where a new flank window would look directly into a neighbour's garden, we typically specify obscure or high-level glazing to address it before submission rather than after an objection.
Do I need an architect for a double storey extension?+
No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings and in-house structural coordination as an architect, for a fixed fee typically around 30% lower, with structural calculations for the additional floor produced by the same team rather than a separately appointed engineer.
How long does it take to get double storey extension drawings?+
Drawings are typically ready around 7 days from survey. A householder planning application then has a statutory 8-week determination period once submitted.
Do I need planning permission for an extension in Bromley?+
Bromley has no borough-wide Article 4 direction affecting typical householder permitted development, so its detached and semi-detached homes often keep fuller rights than inner-London terraces — larger rear and single-storey extensions can qualify. The binding constraints are green-belt policy on outer properties and conservation control in Chislehurst, Keston and Bromley Town. We check both and can confirm permitted development with a Lawful Development Certificate.
Can I build a bigger extension because Bromley plots are larger?+
Often, yes. Bromley's generous interwar plots make substantial rear and double-storey extensions viable where an inner-London terrace could not accommodate them. The limit is usually policy rather than space — green belt restricts scale on outer properties, and conservation areas control design. We design to use the plot fully within those limits, checking permitted-development allowances for detached homes first.
How does green-belt designation affect my Bromley project?+
On green-belt properties toward Orpington, Chislehurst and the borough's edges, extensions are assessed against strict limits on disproportionate additions to the original dwelling. It does not rule out an extension, but scale and siting matter and the case must be evidenced carefully. We confirm whether your property is green belt and design a scheme that stays within policy.
How long does Bromley Council take to decide?+
Bromley determines most householder applications within the statutory eight-week period once validated. As London's largest borough by area, its casework spans suburban semis to green-belt properties, so a complete, correctly scaled submission is the best way to avoid a validation query and keep to that timescale.
How much do planning drawings cost in Bromley?+
We quote a fixed fee upfront, typically around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Bromley approves. Because plots here allow larger schemes, the fee tracks the project's complexity — a single-storey rear differs from a double-storey or a green-belt case — and we confirm it once we understand your plans.
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