Two-storey extension drawings for Lambeth homes — bedroom above, living space below, drawn against the 3-metre projection and 7-metre boundary rules and to Lambeth Council's design guidance, delivered in days and revised free until your decision.
Lambeth Council granted 89% of the householder planning decisions it made in its latest published year — 2 points above the 87% England-wide householder average. The loss of family houses to further flat conversion is resisted and frequently the deciding issue, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837), Victorian (1837–1901) and Edwardian (1901–1910) housing stock sets the design brief on most streets.
Before permission is required, Class B allows 40m³ of added loft volume on a terrace and 50m³ on a semi or detached house, and Class A allows a 3m single-storey rear extension on a terrace or 4m on a detached house. Lambeth carries at least one Article 4 direction, and conservation areas including Clapham Old Town, Stockwell Park and Angell Town remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Lambeth is determined against an 8-week statutory target.
Clapham (Georgian and Victorian terraces around the Old Town and Common), Brixton (Victorian terraces heavily subdivided into flats), Stockwell (Georgian and Victorian streets around Stockwell Park), Herne Hill (Victorian villas and terraces on the Dulwich fringe), Streatham (Edwardian terraces and mansion blocks along the high road) and Kennington (Georgian and Regency terraces near the river) — these are the Lambeth pockets our drawings cover most. Heritage designations here include Clapham Old Town, Stockwell Park, Angell Town, Herne Hill and Leigham Court Estate. Lambeth Council weighs each proposal against Lambeth Local Plan and the council's Alterations and Extensions SPD, where mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. Much of Brixton, Clapham and Stockwell is already converted flats and maisonettes, which hold no householder permitted-development rights.. On roofs the borough is butterfly and valley roofs behind the terrace parapets and mansard and pitched roofs on the taller stucco streets, over Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and estates.
Adding at first floor changes the question the case officer asks. A single-storey extension is judged mostly on daylight and garden loss; a two-storey extension is judged on overlooking, bulk against the neighbouring roofline, and whether it reads as part of the house or bolted onto it. Lambeth is largely Georgian and Victorian terraces, converted flats and maisonettes and purpose-built mansion blocks and estates, and butterfly and valley roofs behind the terrace parapets and mansard and pitched roofs on the taller stucco streets set what a matching roof actually means here.
The permitted-development route exists but is narrow: 3 metres of rear projection, a 7-metre stand-off from the rear boundary, eaves and ridge no higher than the original, and side-facing upper windows obscure-glazed and non-opening below 1.7 metres above floor level. Most two-storey schemes fail one of those, usually the 7-metre boundary rule on a shorter garden, and go in as a full application instead. We establish which route applies before designing, because it changes the drawing set.
The loss of family houses to further flat conversion is resisted and frequently the deciding issue. Alongside the controls in conservation areas such as Clapham Old Town, Lambeth runs a borough-wide Article 4 direction removing permitted-development rights for small shared houses, pulling many HMO changes into the application system.
Some two-storey rear extensions are permitted development. You will need a full application to Lambeth Council if any of these apply:
We set the projection and boundary distance on the site plan, prove the roof-pitch match on the elevations, and specify obscure glazing on the side windows — the three things Lambeth Council checks first — then submit a validation-complete pack.
Below is Lambeth Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Lambeth grants a high proportion of householder applications, but with so much of its stock already split into flats, protecting the remaining family houses is what shapes most refusals. Two-storey schemes attract more neighbour comment than any other householder work, so the overlooking and daylight case has to be made on the drawings.
Source: MHCLG planning application statistics (householder decisions, rolling year). Compare every borough on our London approval-rate league table.
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Across Clapham, Brixton and Stockwell, the schemes that succeed set the first floor back from the ground floor, keep the ridge below the original, and treat the flank wall as blank or obscure-glazed. On georgian and victorian terraces, matching the eaves line matters more than matching the brick: an extension that carries the existing eaves through reads as original even in a different material.
Mansards and roof additions on stucco-fronted terraces are measured against whatever original roofline survives on the street. We draw the 45-degree daylight test from the neighbour's nearest habitable window, show the window positions in section, and set out the steel and foundation implications early — a two-storey extension changes the load path, so the structural design and the planning design have to be developed together rather than in sequence.
We draw two-storey extensions across Lambeth. A few of the areas where they come up most often:
Two storey extension drawings for Clapham — Georgian and Victorian terraces around the Old Town and Common — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
Two storey extension drawings for Brixton — Victorian terraces heavily subdivided into flats — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
Two storey extension drawings for Stockwell — Georgian and Victorian streets around Stockwell Park — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
Two storey extension drawings for Herne Hill — Victorian villas and terraces on the Dulwich fringe — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
Two storey extension drawings for Streatham — Edwardian terraces and mansion blocks along the high road — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
Two storey extension drawings for Kennington — Georgian and Regency terraces near the river — dimensioned against the 3m and 7m limits and drawn to Lambeth Council's guidance.
The first-floor limits are tighter than the ground-floor ones. This is how the common cases compare.
| Scheme | Permitted development? | Deciding limit | What Lambeth Council checks |
|---|---|---|---|
| Two-storey rear, 3m projection, 7m+ to boundary | Often yes | 3m projection / 7m boundary | Roof match, side-window glazing |
| Two-storey rear, under 7m to boundary | No — full application | Rear-boundary distance | Overlooking, daylight, garden loss |
| Two-storey side extension | No — full application | Side elevation | Gap to boundary, street rhythm |
| Two-storey wraparound | No — full application | Combined footprint | Bulk, massing, neighbour amenity |
| Any two-storey on designated land | No — full application | Designation | Character and appearance |
Limits from the GPDO 2015, Schedule 2, Part 1, Class A — two-storey rear extension conditions.
A fixed process built around how Lambeth Council validates and decides two-storey applications.
Send us your Lambeth postcode and garden depth. We measure the 7-metre boundary rule against your plot, confirm designation status, and score your odds against live Lambeth Council decisions.
We measure the original rear wall, eaves and ridge heights, garden depth and every neighbouring window that faces the site — the inputs the daylight and overlooking case is built from.
Chartered designers develop the two-storey addition to your brief with the roof and eaves resolved, and we coordinate the load path so the structural scheme and the planning scheme are the same building.
We submit the application, manage validation and case-officer queries, and revise the drawings free until Lambeth Council issues its decision.
Often, but not always. A two-storey rear extension can be permitted development if it projects no more than 3 metres, sits at least 7 metres from the rear boundary, does not exceed the existing eaves and ridge, and has obscure-glazed non-opening side windows below 1.7 metres. In Lambeth, the 7-metre rule is what most commonly forces a full application to Lambeth Council.
No part of a permitted-development two-storey rear extension may come within 7 metres of the boundary opposite the rear wall of the house. It exists to protect the neighbour behind you from being overlooked at first floor. On shorter Lambeth gardens this is decisive, and we measure it on survey before any design work rather than discovering it at validation. Lambeth Council is the decision-maker.
Not under permitted development — two-storey side extensions always need a full application to Lambeth Council. They are assessed on the gap to the boundary, whether the street's rhythm of spaces between houses survives, and whether the extension is subordinate to the original. Setting the first floor back from the front building line and down from the ridge is what usually makes the difference.
Overlooking is the most common objection, and it is answerable on the drawings. We position habitable-room windows away from neighbouring gardens, obscure-glaze and fix shut anything on the flank below 1.7 metres, and show the sight lines in section. Where the geometry is tight, a rooflight or a high-level window gives the same daylight without the mutual overlooking that draws objections. This applies to your Lambeth address specifically. Lambeth Council is the decision-maker.
Almost certainly. Excavating within 3 metres of a neighbouring structure and building on or up to the boundary both trigger the Party Wall etc. Act 1996, and a two-storey extension usually does both. It is entirely separate from Lambeth Council's planning decision, so we flag the notice period early and detail the junction on the drawings.
Yes. Adding a floor changes the load path from roof to foundation, so beams, padstones and foundation depths all need designing and calculating for building control. Planning and building regulations are separate consents, and the structural set is what building control assesses — we prepare both so the approved scheme is the buildable one. This applies to your Lambeth address specifically. Lambeth Council is the decision-maker.
We quote each Lambeth two-storey extension individually, because plot depth, roof form and structural complexity vary house to house, and send a fixed, no-obligation quote within one working day. It covers the drawing pack with free revisions until Lambeth Council approves. Call 020 7864 7245 to start.
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