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Free 2026 London Planning ReportStructural Drawings in Streatham SW16

Converted Victorian house interior in Streatham SW16, a typical Lambeth flat-conversion and extension project
Streatham · SW16 · Lambeth

Structural Drawings in Streatham SW16

Fixed-fee, MCIAT-chartered structural drawings for Streatham (SW16) homeowners — London Borough of Lambeth validation and local constraints handled from the start.

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Streatham (SW16) is a long, mixed Lambeth neighbourhood that runs from the terraces off the High Road out to the interwar semis of Streatham Vale. The most consistent control is the Streatham Common conservation area, which governs roof form, materials and frontages for houses around the Common — a very different context from the standard terraces further north where side-return and loft projects follow the usual pattern.

Because the housing grain shifts from terrace to semi across the district, the right extension approach genuinely varies street to street. We establish where a Streatham property sits relative to the Common conservation area and the High Road frontage, then prepare the drawings to Lambeth's residential design and validation standards.

Converted Victorian house interior in Streatham SW16, a typical Lambeth flat-conversion and extension project
Isometric illustration of a Streatham SW16 home structural drawings design
Proposed floor plan
Streatham SW16

Planning in Streatham (SW16): what to know before you apply

SW16 has no householder Article 4 direction, so many Streatham houses retain permitted development rights — but the Streatham Common conservation area is the exception, and the interwar semis toward Streatham Vale carry different design expectations from the Victorian terraces nearer the High Road.

Typical Streatham housing stock

Victorian and Edwardian terraces on the streets off Streatham High Road, interwar semi-detached houses toward Streatham Vale and Norbury, and mansion blocks along the High Road and around the Common.

Streets we regularly draw for in Streatham

Streatham High Road · Mitcham Lane · Leigham Court Road · Streatham Common North

What SW16 is actually built of

Measured from 471 classified residential buildings in SW16, not from a description of the area.

Streatham SW16 housing mix

Residential building form across the SW16 postcode district, from 471 classified buildings.

Attached on more than one side53%
Attached on one side38%
Detached9%
Median building footprint69 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate1.68
Buildings classified471

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.

Structural Drawings for Streatham (SW16) homes: the package and the process

Structural sheets are issued to be built from. Beam and lintel schedules give size, grade and bearing; connection details show how each element meets the next; and padstones, straps and restraint are drawn at the junctions rather than noted in general terms. Calculations are submitted alongside so Building Control can check the design rather than take it on trust.

Coordination with the architectural set is where the value is. A beam that is right in isolation but sits below the approved ceiling line, or a column that lands in a doorway, is a site problem that costs more to fix than it did to draw. We resolve those clashes in the drawing stage.

The existing structure sets the design. A terrace transfers load through party walls that are shared and often unrecorded, a semi through one; and floor construction — timber, concrete, or a mix from earlier alterations — changes how a new opening is supported and what has to be exposed to find out.

Do I need structural calculations to remove a load-bearing wall in London?

If a wall carries any load from above — a floor, a roof, another wall, or a chimney breast — you need a structural calculation before it can be removed, and Building Control will ask for it as part of a Full Plans or Building Notice submission. This covers the great majority of kitchen-diner knock-throughs in London terraces and semis, where the wall between the kitchen and the rear reception room is almost always load-bearing. A calculation confirms the size and type of steel beam needed to replace the wall's support, the padstones or pier that carry the beam's weight down to the foundations, and the temporary propping needed while the work is carried out. If the wall shares a boundary or the new beam bears on a party wall, the Party Wall etc. Act 1996 will also apply and needs to be dealt with separately from the calculation itself.

How steel beam sizing works

A structural engineer calculates the loads bearing down on a wall from the floors, roof and any walls above it, then sizes a steel beam (RSJ) — its depth, width and steel grade — so it can safely carry that load across the required span without excessive deflection. The calculation also fixes the bearing length at each end, the padstones or steel plates that spread the load into the surrounding masonry, and whether the existing foundations need strengthening to take the extra point loads. Because we coordinate the calculation with the architectural drawing set, the exact beam size, orientation and position shown on your plans is the one the calculation specifies — so your builder can order the correct steel first time, and Building Control sees a consistent set of drawings rather than two documents that disagree.

How much do structural drawings cost in London?

Structural drawings and calculations start from £650 for a single beam or wall removal, agreed as a fixed fee before work begins. The price depends on the number of beams or walls involved, whether foundations need designing from scratch (as with a rear or side extension), whether existing floor and roof structures need checking for extra loading (as with most loft conversions), and whether retaining or underpinning calculations are required, as they are for basement conversions. Where structural work is part of a wider extension, loft or basement project, the structural calculation is typically bundled into the overall building regulations fee rather than charged again separately.

Typical structural drawing scope by project
Project scopeWhat's includedFee guide
Single beam or wall removalOne steel calculation plus a drawing showing beam size, padstones and bearingsFrom £650
Loft conversion structural packageFloor and roof loading checks, beam calculations, staircase opening designIncluded within loft drawings from £1,100
Rear or side extension structural packageFoundation design, steel beam calculations, roof loading checksIncluded within planning and building regs packages from £2,200–£3,850
Basement or retaining structureUnderpinning, retaining wall and waterproofing-adjacent structural calculationsQuoted individually — ground conditions vary
Sheet from a structural drawings package drawn for a Streatham property in SW16, showing the existing and proposed arrangement at scale
A sheet from the structural drawings package we submit to London Borough of Lambeth for Streatham (SW16) properties.
FAQ

Structural Drawings in Streatham SW16 — FAQs

Do I need a structural engineer to remove a wall in my London home?+
Yes, if the wall is load-bearing — which most internal walls between a kitchen and reception room are. We coordinate the structural calculation in-house alongside your drawings, so you do not need to find and brief a separate engineer yourself.
How long do structural calculations take?+
Structural drawings are typically ready within about 7 days of instruction, in line with the rest of our drawing packages, and are produced alongside your architectural and building regulations drawings so everything is issued together.
Will the steel beam on my drawings match what my builder orders?+
Yes — because we produce the architectural drawings and coordinate the structural calculation together, the beam size, position and bearings shown on your plans are the ones the calculation specifies, so there is nothing for your builder to reconcile on site.
Can you produce structural drawings without handling my full planning application?+
Yes, a standalone structural calculation is available if you already have architectural drawings and just need a wall or beam calculated and signed off for Building Control.
Do structural calculations need to be submitted to Building Control?+
Yes — a structural calculation is a required part of a Full Plans or Building Notice submission wherever a load-bearing wall, beam or foundation is involved, and Building Control will not approve the work without one.
Do I need planning permission for a side-return extension in Lambeth?+
On many of Lambeth's Victorian and Edwardian terraces in Brixton, Clapham and Streatham, a single-storey side-return or rear extension can fall within permitted development, so a full application isn't always required. Conservation areas such as Clapham Common and Brixton Water Lane can restrict this. We check your street's designation first and can confirm permitted development with a Lawful Development Certificate.
My Lambeth home is a converted flat — does that change things?+
It often does. Many Lambeth houses are converted flats, so ownership, lease and party-wall considerations can matter as much as the planning route, and the freeholder's agreement is usually needed alongside planning. We resolve the ownership and shared-structure context before drawing so the scheme is deliverable, not just consentable.
What does Lambeth's HMO Article 4 direction affect?+
Lambeth applies an Article 4 direction removing permitted development rights for HMO conversions (C3 to C4) in designated parts of the borough, so a change of use to a house in multiple occupation needs a full application there. It doesn't affect a standard family extension, but we confirm whether it applies to your address and use before advising on a route.
How long does Lambeth Council take to decide?+
Lambeth determines most householder applications within the statutory eight-week period once validated. The terraced grids around Clapham and Brixton are party-wall-sensitive with well-established design expectations, so the commonest delay is a drawing query — we prepare submissions to the borough's residential extension guidance to keep them moving.
How much do planning drawings cost in Lambeth?+
We agree a fixed fee before starting, usually around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Lambeth approves. A side-return, a loft and a flat-conversion scheme differ in complexity, so we quote once we understand your street and project rather than charging by the hour.
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