MCIAT chartered drawings · Fixed fees across all 33 London boroughs

Free 2026 London Planning ReportNew Build Drawings in Sidcup DA15

Kitchen extension interior in a 1930s Sidcup DA15 semi, London Borough of Bexley
Sidcup · DA15 · Bexley

New Build Drawings in Sidcup DA15

Fixed-fee, MCIAT-chartered new build drawings for Sidcup (DA15) homeowners — London Borough of Bexley validation and local constraints handled from the start.

Free Sidcup planning assessment

Tell us your Sidcup (DA15) address and project. A fixed quote and free planning appraisal land within one working day.

No obligation · No spam · Reply within 1 working day

Sidcup's DA15 stretches north and west from the town toward Blackfen, Lamorbey and Longlands, mixing broad inter-war suburban avenues with older hamlets along Halfway Street and Burnt Oak Lane. Side-return, rear and loft extensions on the 1930s semis are the everyday work, but two designated conservation areas change the rules on specific streets.

The Halfway Street Conservation Area, designated in 1985, protects some of the oldest cottages in the borough around Holy Trinity Church, while the Longlands Road Conservation Area of 1992 guards an almost unaltered inter-war estate. Both carry Article 4 Directions, so alterations that are automatic elsewhere in DA15 need a full application within their boundaries.

Kitchen extension interior in a 1930s Sidcup DA15 semi, London Borough of Bexley
Isometric illustration of a Sidcup DA15 home new build drawings design
Proposed floor plan
Sidcup DA15

Planning in Sidcup (DA15): what to know before you apply

Within the Halfway Street and Longlands Road conservation areas the Article 4 Directions withdraw permitted development for elevation, roof, window and front-boundary changes, so alterations that are automatic on nearby 1930s streets need a householder application here. Elsewhere in DA15 — the wider Blackfen, Lamorbey and Longlands suburbs — rear and loft extensions on the inter-war semis commonly remain permitted development, subject to the usual size and height limits.

Typical Sidcup housing stock

Sidcup's DA15 stock runs from some of the oldest houses in the borough — the 17th- and 18th-century cottages lining Halfway Street and Burnt Oak Lane — to the almost unaltered inter-war semi-detached estate of Longlands Road, with broad Edwardian and 1930s suburban avenues around Blackfen and Lamorbey in between.

Streets we regularly draw for in Sidcup

Halfway Street · Burnt Oak Lane · Longlands Road · Blackfen Road

What DA15 is actually built of

Measured from 387 classified residential buildings in DA15, not from a description of the area.

Sidcup DA15 housing mix

Residential building form across the DA15 postcode district, from 387 classified buildings.

Attached on more than one side42%
Attached on one side50%
Detached8%
Median building footprint67 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate1.04
Buildings classified387

Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.

New Build Drawings for Sidcup (DA15) homes: the package and the process

A new dwelling is a full application rather than a householder one, and the drawing set reflects that: site layout with levels and boundaries, floor plans and elevations for the new building, sections showing how it sits in the ground, and street-scene elevations placing it against what is already there.

Two packages follow the approval — the planning set and the construction set — and they have to stay in step. Foundation design, drainage strategy, thermal performance and fire strategy are drawn for Building Control against the same geometry that was granted permission, so the built house matches the approved one.

An infill plot is designed against its neighbours. Plot width, the building line either side, and the ridge heights next door set what the new house can be — and on a tight urban site those constraints usually shape the design more than the brief does.

Is my plot suitable for a new build in London?

A feasibility assessment looks at plot size and shape, access, existing boundary conditions, relevant planning policy for the borough, and the likely impact of a new dwelling on neighbouring properties before any design work begins. Infill plots — a gap between existing buildings on a street — and backland plots — a garden or yard site behind existing houses, reached by a shared access — each raise different issues: infill schemes are usually judged on how well they match the scale, spacing and character of the street, while backland schemes are judged heavily on overlooking, garden loss for neighbours, and whether the access arrangement is acceptable. A feasibility study gives an honest view of whether a scheme is likely to succeed before you commit to full drawings.

What does pre-application advice add to a new build project?

Pre-application advice is a formal, paid process most London boroughs offer, where planning officers give written feedback on a proposed scheme before a full application is submitted. For a new build — where the principle of development itself is often the main issue, not just the design details — this feedback can be invaluable: it surfaces concerns around density, massing, daylight and sunlight or heritage context early enough to be addressed in the drawings, rather than discovered for the first time as a refusal reason months into a full application. We prepare and submit pre-application enquiries as part of the new build service where it is likely to strengthen the eventual planning application.

How do daylight, sunlight and overlooking affect a new build design?

London boroughs assess new dwellings against their effect on the daylight and sunlight reaching neighbouring homes and gardens, commonly using the 45-degree rule as an initial check on a proposal's massing and position relative to neighbouring windows, alongside more detailed daylight and sunlight assessment on sensitive sites. Overlooking and loss of privacy from new windows, upper floors or roof terraces are assessed similarly, and often shape decisions on window placement, floor-to-floor heights and the overall footprint and massing of the new building. Designing with these constraints from the earliest sketch stage, rather than adjusting for them after a refusal, is one of the main advantages of instructing feasibility and pre-application work before a full planning set.

New build project stages
StageWhat it establishesTypical fee guide
FeasibilityWhether the plot can support a new dwelling and the likely constraintsQuoted individually, from within the £2,500 new build fee
Pre-application adviceWritten borough feedback on the scheme before a full applicationQuoted individually alongside the planning fee
Full planning drawingsThe complete drawing set submitted for planning permissionFrom £2,500
Building regs and structuralConstruction-ready drawings and calculations for buildingFrom £2,200–£3,850, quoted once planning is settled
Sheet from a new build drawings package drawn for a Sidcup property in DA15, showing the existing and proposed arrangement at scale
A sheet from the new build drawings package we submit to London Borough of Bexley for Sidcup (DA15) properties.
FAQ

New Build Drawings in Sidcup DA15 — FAQs

How much do new build drawings cost in London?+
New build drawings start from £2,500 for feasibility and a full planning drawing set on a straightforward infill or backland plot, with building regulations and structural drawings quoted separately once the planning design is agreed.
Can any garden or backland plot be built on in London?+
Not necessarily — backland and garden plots are assessed on access, overlooking, loss of garden amenity for neighbours and borough policy, and a feasibility assessment gives an honest early view of whether a scheme is likely to be supported.
Do I need pre-application advice before a full new build application?+
It is not mandatory, but for a new dwelling — where the principle of development is often the main issue — pre-application advice can surface concerns early enough to address them in the design, reducing the risk of refusal.
Do you handle building regulations and structural drawings for a new build, or only planning?+
Both — the full new build service covers planning, building regulations and structural drawings from one in-house team, so the design stays consistent from feasibility through to construction-ready drawings.
How long does a new build project take from feasibility to planning permission?+
This varies with site complexity and whether pre-application advice is sought, but a full planning application is determined within the statutory period the borough applies to the application type, once submitted via the Planning Portal.
Do I need planning permission for an extension in Bexley?+
Bexley has no borough-wide Article 4 direction affecting typical householder permitted development, so its semi-detached homes often keep fuller rights than inner-London terraces — larger rear and single-storey extensions can qualify. Conservation areas such as Old Bexley Village and Danson Park, and riverside flood-zone constraints toward Erith, restrict this. We check your address first and can confirm permitted development with a Lawful Development Certificate.
Can I build a bigger extension because Bexley plots are larger?+
Often, yes. The generous interwar plots across Bexleyheath, Sidcup and Welling make substantial rear and double-storey extensions viable where a tight terrace could not. The limit is usually design and amenity policy rather than space. We design to use the plot fully within permitted-development allowances or a well-evidenced full application.
What extra control applies in Old Bexley Village or around Danson Park?+
These conservation areas carry design control over materials, rooflines and front elevations, and the Upton area of Bexleyheath includes the setting of William Morris's Red House. Permitted development is often restricted there, so we design to the area's character and prepare a full, context-led application where a standard permitted-development route doesn't apply.
How long does Bexley Council take to decide?+
Bexley determines most householder applications within the statutory eight-week period once validated; conservation cases can involve additional consultation. A complete, correctly scaled submission is the best way to avoid a validation query — we prepare Bexley drawings to the council's checklist to keep the application on track.
How much do planning drawings cost in Bexley?+
We quote a fixed fee upfront, typically around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Bexley approves. Because plots here allow larger schemes, the fee tracks complexity — a single-storey rear differs from a double-storey — and we confirm it once we understand your plans.
Free Fixed Quote

Get your free Sidcup planning assessment

Tell us your Sidcup (DA15) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.