Dormer, hip-to-gable and mansard loft conversion drawings for Langley St Mary's homes — prepared to Slough Borough Council's design guidance, delivered in days and revised free until your decision lands, with a free approval-odds score first.
Slough Borough Council granted 82% of the householder planning decisions it made in its latest published year — 5 points below the 87% England-wide householder average. Langley St Mary's contains St Bernard's School, St Mary's Church, Langley conservation areas (St Mary's Church, Langley designated 1977), so materials, fenestration and roof form are assessed against the appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant interwar (1918–1939) and postwar (1945–1970) 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. In conservation areas such as St Bernard's School and St Mary's Church, Langley those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in Langley St Mary's is determined against an 8-week statutory target.
St Bernard's School (designated conservation area) and St Mary's Church, Langley (conservation area designated in 1977) — these are the Langley St Mary's pockets our drawings cover most. Heritage designations here include St Bernard's School and St Mary's Church, Langley. Slough Borough Council weighs each proposal against the adopted Slough local plan and Slough Borough Council's design guidance for householder work, where the 2,090 homes here are 36% 1955-1964, 10% 1930-1939, 9% 1965-1972, which is what sets the realistic roof and rear-projection options. On roofs the borough is shallow gabled roofs typical of that period's building and hipped roofs with shallow pitches typical of 1930s building, over late-1950s and early-1960s houses (36% of 2,090 homes), 1930s semi-detached and detached houses (10%) and late-1960s and early-1970s houses (9%).
What is permitted in Langley St Mary's turns on designation first, so that is where we start: St Bernard's School (designated conservation area) and St Mary's Church, Langley (conservation area designated in 1977). Inside those boundaries permitted development is curtailed and Slough Borough Council assesses materials, window detail and roof form against the area's own appraisal, so a scheme that would be waved through two streets away can need a full application here.
No Article 4 direction is recorded for Slough Borough Council, but Langley St Mary's's 2 conservation areas still limit permitted development on those streets.
On stock, Langley St Mary's is late-1950s and early-1960s houses (36% of 2,090 homes), 1930s semi-detached and detached houses (10%) and late-1960s and early-1970s houses (9%) — which is why shallow gabled roofs typical of that period's building and hipped roofs with shallow pitches typical of 1930s building govern what a loft or rear projection can realistically be. Slough Borough Council decided 417 householder applications in the latest published year and granted 82%, with 42% issued inside the eight-week target. We draw to that record rather than to a national average.
The full build-period split for Langley St Mary's runs pre-1900 1% (30 homes), 1900-1918 1% (20 homes), 1919-1929 2% (50 homes), 1930-1939 10% (210 homes), 1945-1954 0% (10 homes), 1955-1964 36% (760 homes), 1965-1972 9% (190 homes), 1973-1982 7% (140 homes), 1983-1992 3% (70 homes), 1993-1999 0% (10 homes) and 2000-2008 8% (160 homes). That distribution is why pre-1900 detailing dominates the drawings here, and it is measured from council-tax records rather than assumed from the street name.
Slough Borough Council also decides for Colnbrook & Poyle, so a decision in Langley St Mary's sits inside a wider pattern of decisions we track across the same authority — useful when an officer cites a precedent from the next area over.
Published figures for Langley St Mary's and Slough Borough Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | Langley St Mary's |
|---|---|
| Dwellings recorded | 2,090 |
| Built pre-1900 | 30 (1%) |
| Built 1900-1918 | 20 (1%) |
| Built 1919-1929 | 50 (2%) |
| Built 1930-1939 | 210 (10%) |
| Built 1945-1954 | 10 (0%) |
| Built 1955-1964 | 760 (36%) |
| Built 1965-1972 | 190 (9%) |
| Built 1973-1982 | 140 (7%) |
| Built 1983-1992 | 70 (3%) |
| Built 1993-1999 | 10 (0%) |
| Built 2000-2008 | 160 (8%) |
| Built before 1919 | 2% |
| Built 1919–1939 | 12% |
| Built 1945–2008 | 64% |
| Conservation areas in Langley St Mary's | 2 (St Bernard's School, St Mary's Church, Langley) |
| Conservation areas district-wide | 5 |
| Article 4 directions recorded | 0 |
| Householder applications decided | 417 |
| Householder applications granted | 82% |
| Decided within 8 weeks | 42% |
Dwelling stock from VOA council-tax data at 31 March 2025; conservation-area and Article 4 counts from planning.data.gov.uk (MHCLG); decision figures are Slough Borough Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
Langley St Mary's's roofs set the brief. The borough is built largely from late-1950s and early-1960s houses (36% of 2,090 homes), 1930s semi-detached and detached houses (10%) and late-1960s and early-1970s houses (9%), and its lofts sit under shallow gabled roofs typical of that period's building and hipped roofs with shallow pitches typical of 1930s building — the geometry that decides whether a rear dormer, a hip-to-gable or a mansard gives you the headroom you want. Slough Borough Council assesses loft proposals against the adopted Slough local plan and Slough Borough Council's design guidance for householder work, and its case officers read each roof against the pair next door and the wider street before they read the plans.
That makes drawing quality decisive. We measure ridge and eaves heights, roof pitch and the existing stair, calculate the added volume against the permitted-development limits exactly, and show the workings on the drawings so Slough Borough Council can verify them. Langley St Mary's contains St Bernard's School, St Mary's Church, Langley conservation areas (St Mary's Church, Langley designated 1977), so materials, fenestration and roof form are assessed against the appraisal, so we resolve it on the page rather than leave it for the case officer to raise.
Langley St Mary's also carries protected streets — St Bernard's School and St Mary's Church, Langley among them. No Article 4 direction is recorded for Slough Borough Council, but Langley St Mary's's 2 conservation areas still limit permitted development on those streets. We check your address against those designations before a line is drawn.
Many Langley St Mary's loft conversions proceed without planning permission — a rear dormer within the permitted-development volume limits (40 cubic metres on a terrace, 50 on a semi or detached house) is usually lawful. You will normally need a full application to Slough Borough Council if any of these apply:
We draw the roof line, the ridge height and the neighbour's daylight on the page — the relationships Slough Borough Council's officers check first — and submit a validation-complete pack, whether that is a lawful development certificate or a full householder application.
Below is Slough Borough Council's real householder decision record, pulled from official planning statistics and updated as new data lands. Slough Borough Council granted 82% of its householder applications in the year to 31 March 2026, and St Bernard's School shapes what is approved here. Professionally prepared loft drawings anticipate those pressure points before submission, which is why complete, policy-literate packs are decided faster and refused less often than DIY applications.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
Tell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Across St Bernard's School and St Mary's Church, Langley, the recurring loft is the rear dormer — a box across the back roof slope that turns a cramped attic into a full-height double bedroom and en-suite. On shallow gabled roofs typical of that period's building, that is usually the most efficient use of the roof; where the stock is hipped roofs with shallow pitches typical of 1930s building, a hip-to-gable followed by a rear dormer unlocks far more space, though it needs a full application.
The 2,090 homes here are 36% 1955-1964, 10% 1930-1939, 9% 1965-1972, which is what sets the realistic roof and rear-projection options. We draw the dormer inside the volume allowance, keep the flat-roof build-up below the ridge, and set the face back from the eaves as the rules require — so the pack answers Slough Borough Council's questions before they are asked. Where permitted-development rights are exhausted or removed, we prepare a householder application composed to the borough's roof-alteration guidance instead.
We draw loft conversions on every street in the borough. A few of the neighbourhoods where Langley St Mary's roofs come up most often:
Loft conversion drawings for St Bernard's School's designated conservation area — measured, volume-checked and drawn to Slough Borough Council's guidance.
Loft conversion drawings for St Mary's Church, Langley's conservation area designated in 1977 — measured, volume-checked and drawn to Slough Borough Council's guidance.
The right loft in Langley St Mary's depends on your roof. This is how the main types compare on planning route and the space they add.
| Loft type | Permitted development? | Space & headroom | What Slough Borough Council checks |
|---|---|---|---|
| Rear dormer | Usually yes, within volume limits | Full-height double room at the back | Volume, set-back from eaves, ridge height |
| Hip-to-gable | No — full application | Extends the whole side of the roof | Roof bulk and the symmetry of the pair |
| Mansard | No — full application | Maximum floor area across the roof | Street character, especially in conservation areas |
| Rooflights only | Usually yes (Class C) | Light and headroom, no extra footprint | Whether rooflights sit within the existing slope |
Route depends on your street — conservation areas such as St Bernard's School and St Mary's Church, Langley and Article 4 directions can remove permitted-development rights.
A fixed process built around how Slough Borough Council validates and decides householder loft applications — most drawings are submission-ready within seven days of survey.
Tell us your Langley St Mary's postcode and roof type. We confirm your conservation and Article 4 status, how much permitted-development volume you have left, and score your odds against live Slough Borough Council decisions.
We measure ridge and eaves heights, roof pitch, joist levels and the existing stair — the numbers the volume calculation and head heights depend on.
Chartered designers develop the dormer, hip-to-gable or mansard to your brief, drawn inside the Class B limits or to Slough Borough Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Slough Borough Council issues its decision.
Often not. A rear dormer within 40 cubic metres on a terrace, or 50 on a semi-detached or detached house, set back from the eaves and no higher than the ridge, is usually permitted development. In Langley St Mary's the main exceptions are hip-to-gable conversions, dormers visible from the highway, and homes in conservation areas such as St Bernard's School and St Mary's Church, Langley or on streets with an Article 4 direction. Slough Borough Council is the decision-maker.
Generally no. In conservation areas including St Bernard's School and St Mary's Church, Langley, Class B permitted-development rights for lofts are removed, so a rear dormer that would be lawful elsewhere needs a full application to Slough Borough Council. No Article 4 direction is recorded for Slough Borough Council, but Langley St Mary's's 2 conservation areas still limit permitted development on those streets. We check your exact address before drawing.
On shallow gabled roofs typical of that period's building, common across Langley St Mary's, a rear dormer is usually the most efficient conversion and often permitted development. Where the roof is hipped roofs with shallow pitches typical of 1930s building, a hip-to-gable followed by a rear dormer gains far more usable space but needs planning permission. Our survey confirms which your roof supports before we draw. Slough Borough Council is the decision-maker.
A householder planning application in Langley St Mary's runs to a statutory eight-week target, and a lawful development certificate to eight weeks as well, though validation can add time if the pack is incomplete. We submit validation-complete drawings and manage case-officer queries to keep the decision on track. Slough Borough Council is the decision-maker.
If your dormer is permitted development, a lawful development certificate from Slough Borough Council is council-stamped proof of that — worth having, because every buyer's solicitor will ask for it when you sell. We prepare and submit the certificate application with the same drawing pack. This applies to your Langley St Mary's address specifically.
Every roof is different, so we quote each Langley St Mary's project individually — a fixed, no-obligation price back within one working day. The quote covers the full drawing pack with free revisions until Slough Borough Council approves, and we tell you upfront whether your loft qualifies as permitted development. Call 020 7864 7245 to start.
Answer five quick questions and get a free planning score for your exact address — instantly. Then, if you want the full picture, unlock the detailed analysis: your council's live approval rates, local precedents, constraints on your street and a step-by-step route to permission.
Same fixed quotes, same fast drawings — wherever your project is.