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Free 2026 London Planning ReportDouble Storey Extension Drawings in Collier Row RM5

Single-storey rear extension onto a garden behind an interwar semi-detached house in Collier Row RM5 in the London Borough of Havering
Collier Row · RM5 · Havering

Double Storey Extension Drawings in Collier Row RM5

Fixed-fee, MCIAT-chartered double storey extension drawings for Collier Row (RM5) homeowners — London Borough of Havering validation and local constraints handled from the start.

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Collier Row (RM5) took shape as an interwar suburb of Romford, expanding through the 1920s and 1930s across former Essex farmland. It is a planned residential district rather than a historic village core, with predominantly semi-detached housing, so almost every householder project here is an extension or loft on one of those consistent interwar pairs.

There is no conservation area covering Collier Row — that is a genuine, verified fact, not an omission. Its planning character is instead shaped by the uniformity of its interwar suburban roads and by the London Borough of Havering's householder design expectations, which favour keeping the semi-detached rhythm, the gaps between pairs and the original materials intact. We treat that suburban cohesion, rather than a conservation designation, as the reference point when we design an extension.

Demand for rear extensions, two-storey side extensions and hip-to-gable lofts is steady across roads like Mawney Road, Silvermere Avenue and Victoria Avenue, where regular plots and gardens are typical. We check each property's permitted-development position against Havering's borough-wide controls first, then prepare drawings that either stay within permitted development or are ready to validate as a full householder application.

Single-storey rear extension onto a garden behind an interwar semi-detached house in Collier Row RM5 in the London Borough of Havering
Isometric illustration of a Collier Row RM5 home double storey extension drawings design
Proposed floor plan
Collier Row RM5

Planning in Collier Row (RM5): what to know before you apply

Because Collier Row's suburban roads repeat so consistently, Havering assess extensions against the established semi-detached pattern, so matching original brick, render and roof form and preserving the gap between pairs matters more than on a mixed-typology road. There is no conservation area and no local Article 4 direction, so many houses retain permitted development rights for rear and loft work — but the finite gardens and shared building lines mean depth, height and neighbour impact are the points a householder application is judged on.

Typical Collier Row housing stock

Predominantly interwar semi-detached houses on planned suburban roads, with postwar and modern infill on regular gardened plots. The consistent pairs and generous front and rear gardens are what makes rear extensions, side extensions and hip-to-gable loft conversions the common projects here.

Streets we regularly draw for in Collier Row

Collier Row Road · Lodge Lane · White Hart Lane · Clockhouse Lane · Mawney Road · Lawns Way · Mashiters Hill · Carter Drive · Ravenswood Close · Hunter's Grove · Silvermere Avenue · Victoria Avenue

Double Storey Extension Drawings for Collier Row (RM5) homes: the package and the process

Every double storey extension drawings we prepare for an Collier Row property is drawn to London Borough of Havering’s validation standards and tuned to the RM5 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 Collier Row RM5 — 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 to extend a house in Collier Row?+
Not always. Many Collier Row semis retain permitted development rights, so a modest single-storey rear extension or a hip-to-gable loft conversion can often proceed without a full planning application. Because the plots are regular but finite and the gap between pairs is protected, we check your property's size limits and building lines against Havering's controls first, and prepare a full householder application where the project goes beyond permitted development — as a two-storey side extension often will.
Is Collier Row in a conservation area?+
No. There is no conservation area covering Collier Row. Its planning character is shaped instead by its uniform interwar semi-detached suburban roads and Havering's householder design expectations, which favour keeping the semi-detached rhythm, the gaps between pairs and the original materials intact when you extend.
How much do planning and building-regulation drawings cost for a Collier Row extension?+
We work to fixed fees agreed before we start, with a typical turnaround of around seven days for a standard rear extension, side extension or loft on a Collier Row semi. As a chartered architectural technologist practice we produce the same council-accepted planning and building-regulation drawings as an architect, usually for a lower fee, and include free redraws until your application is approved.
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