Side-return infill drawings for Boreham and The Leighs terraces — the glazed extension that fills the redundant side alley and opens up the kitchen, drawn to Chelmsford City Council's guidance, delivered in days and revised free until your decision, with a free approval-odds check first.
Chelmsford City Council granted 90% of the householder planning decisions it made in its latest published year — 3 points above the 87% England-wide householder average. Boreham and The Leighs contains Boreham Church Road, Boreham Roman Road and Plantation Road conservation areas (Boreham Church Road designated 1981), so materials, fenestration and roof form are assessed against the appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant postwar (1945–1970) housing stock sets the design brief on most streets.
The permitted-development ceilings are fixed: 40m³ of new roof volume for a terraced loft and 50m³ for a semi or detached house under Class B, plus a 3m single-storey rear extension on a terrace or 4m on a detached house under Class A. Boreham and The Leighs carries at least one Article 4 direction, and conservation areas including Boreham Church Road and Boreham Roman Road and Plantation Road remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Boreham and The Leighs is determined against an 8-week statutory target.
Boreham Church Road (conservation area designated in 1981), Boreham Roman Road and Plantation Road (conservation area designated in 1987), Great and Little Leighs (civil parish within Boreham and The Leighs), Boreham (civil parish within Boreham and The Leighs) and Chelmsford Garden (civil parish within Boreham and The Leighs) — these are the Boreham and The Leighs pockets our drawings cover most. Heritage designations here include Boreham Church Road and Boreham Roman Road and Plantation Road. Chelmsford City Council weighs each proposal against the adopted Chelmsford local plan and Chelmsford City Council's design guidance for householder work, where the 3,080 homes here are 15% 2000-2008, 14% 1973-1982, 13% 1965-1972, which is what sets the realistic roof and rear-projection options. On roofs the borough is trussed-rafter roofs typical of 2000s building and shallow trussed roofs typical of 1970s building, over 2000s houses and apartments (15% of 3,080 homes), 1970s and early-1980s houses (14%) and late-1960s and early-1970s houses (13%).
Before anything is drawn we check your address against the designations that apply in Boreham and The Leighs: Boreham Church Road (conservation area designated in 1981) and Boreham Roman Road and Plantation Road (conservation area designated in 1987). Inside those boundaries permitted development is curtailed and Chelmsford City 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.
Beyond the designated areas, Boreham and The Leighs takes in Great and Little Leighs, Boreham and Chelmsford Garden. Chelmsford City Council has 26 recorded Article 4 directions, removing permitted development for rear and side extensions and roof enlargements such as dormers — check the address before assuming PD applies in Boreham and The Leighs.
On stock, Boreham and The Leighs is 2000s houses and apartments (15% of 3,080 homes), 1970s and early-1980s houses (14%) and late-1960s and early-1970s houses (13%) — which is why trussed-rafter roofs typical of 2000s building and shallow trussed roofs typical of 1970s building govern what a loft or rear projection can realistically be. Chelmsford City Council decided 777 householder applications in the latest published year and granted 90%, with 84% issued inside the eight-week target. That decision record, not a national figure, is what we design to.
The full build-period split for Boreham and The Leighs runs pre-1900 7% (230 homes), 1900-1918 2% (60 homes), 1919-1929 3% (90 homes), 1930-1939 4% (120 homes), 1945-1954 4% (110 homes), 1955-1964 6% (170 homes), 1965-1972 13% (390 homes), 1973-1982 14% (420 homes), 1983-1992 10% (300 homes), 1993-1999 6% (180 homes) and 2000-2008 15% (470 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.
Chelmsford City Council also decides for Chelmsford Rural West and Moulsham and Central, so a decision in Boreham and The Leighs 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.
The Article 4 directions recorded for this council include Ash Tree Stud, Little Waltham, Battlesbridge Conservation Area, Bicknacre Road, East Hanningfield/Danbury and Cedar Park, Graces Lane, Little Baddow. Each removes a specific permitted-development right inside its own boundary, which is why the check is done on the address rather than on the town.
Published figures for Boreham and The Leighs and Chelmsford City Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | Boreham and The Leighs |
|---|---|
| Dwellings recorded | 3,080 |
| Built pre-1900 | 230 (7%) |
| Built 1900-1918 | 60 (2%) |
| Built 1919-1929 | 90 (3%) |
| Built 1930-1939 | 120 (4%) |
| Built 1945-1954 | 110 (4%) |
| Built 1955-1964 | 170 (6%) |
| Built 1965-1972 | 390 (13%) |
| Built 1973-1982 | 420 (14%) |
| Built 1983-1992 | 300 (10%) |
| Built 1993-1999 | 180 (6%) |
| Built 2000-2008 | 470 (15%) |
| Built before 1919 | 9% |
| Built 1919–1939 | 7% |
| Built 1945–2008 | 66% |
| Conservation areas in Boreham and The Leighs | 2 (Boreham Church Road, Boreham Roman Road and Plantation Road) |
| Conservation areas district-wide | 25 |
| Article 4 directions recorded | 26 |
| Householder applications decided | 777 |
| Householder applications granted | 90% |
| Decided within 8 weeks | 84% |
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 Chelmsford City Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
The side return is the classic terrace fix, and Boreham and The Leighs has the stock for it — the borough is built largely from 2000s houses and apartments (15% of 3,080 homes), 1970s and early-1980s houses (14%) and late-1960s and early-1970s houses (13%), and the Victorian and Edwardian versions almost all have an L-shaped back addition with a wasted alley beside it. Fill that alley and the dark galley kitchen becomes a bright, square room the full width of the house. Chelmsford City Council judges the infill against the adopted Chelmsford local plan and Chelmsford City Council's design guidance for householder work, and because it runs along the party boundary, the neighbour relationship is read before the design.
That boundary is where the drawings earn their keep. We set the infill wall on or up to the line, keep the roof — usually a glazed lantern or a shallow pitch tying into the existing back-addition slope — below the neighbour's first-floor windows, and detail the rainwater and party-wall junction so the build is watertight and the Party Wall Act is satisfied. Boreham and The Leighs contains Boreham Church Road, Boreham Roman Road and Plantation Road conservation areas (Boreham Church Road designated 1981), so materials, fenestration and roof form are assessed against the appraisal, so we resolve it on the section rather than leave it to the case officer.
Many of Boreham and The Leighs's terraces sit in conservation areas — Boreham Church Road and Boreham Roman Road and Plantation Road among them — where a side extension is no longer permitted development. Chelmsford City Council has 26 recorded Article 4 directions, removing permitted development for rear and side extensions and roof enlargements such as dormers — check the address before assuming PD applies in Boreham and The Leighs. We confirm the designation before a line is drawn.
Some single-storey side returns in Boreham and The Leighs are permitted development, but the width and boundary make an application more likely than for a straight rear extension. You will normally need to apply to Chelmsford City Council if any of these apply:
We draw the infill wall on the boundary, the glazed roof below the neighbour's windows and the party-wall junction on the page — the details Chelmsford City Council's officers and your neighbour both check — and submit a validation-complete pack, whether that is a lawful development certificate or a full householder application.
Below is Chelmsford City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Chelmsford City Council granted 90% of its householder applications in the year to 31 March 2026, and Boreham Church Road shapes what is approved here. Side returns hinge on width, roof glazing and the party boundary, so a pack that resolves those details upfront is decided faster and refused less often than a DIY submission.
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 Boreham Church Road, Boreham Roman Road and Plantation Road and Great and Little Leighs, the approved side return is a single-storey infill roofed with a glazed lantern or roof light to pull daylight deep into the plan, its flank wall built on the boundary and finished to match the host brick. On the borough's 2000s houses and apartments (15% of 3,080 homes), this is frequently the single biggest gain in usable ground-floor space, and where it stays within the width and height limits it can proceed under permitted development or a lawful development certificate.
The 3,080 homes here are 15% 2000-2008, 14% 1973-1982, 13% 1965-1972, which is what sets the realistic roof and rear-projection options. We keep the glazed roof below the neighbour's cill line, set the gutter and the party-wall flashing so water and maintenance are designed in, and — where owners want the full open-plan room — pair the infill with a rear extension as a single wraparound application. That way Chelmsford City Council sees one coherent scheme rather than two overlapping ones.
We draw side-return infills on every terraced street in the borough. A few of the neighbourhoods where Boreham and The Leighs side returns come up most often:
Side return extension drawings for Boreham Church Road's conservation area designated in 1981 — width-checked, party-wall detailed and drawn to Chelmsford City Council's guidance.
Side return extension drawings for Boreham Roman Road and Plantation Road's conservation area designated in 1987 — width-checked, party-wall detailed and drawn to Chelmsford City Council's guidance.
Side return extension drawings for Great and Little Leighs's civil parish within Boreham and The Leighs — width-checked, party-wall detailed and drawn to Chelmsford City Council's guidance.
Side return extension drawings for Boreham's civil parish within Boreham and The Leighs — width-checked, party-wall detailed and drawn to Chelmsford City Council's guidance.
Side return extension drawings for Chelmsford Garden's civil parish within Boreham and The Leighs — width-checked, party-wall detailed and drawn to Chelmsford City Council's guidance.
Whether a side return in Boreham and The Leighs needs permission comes down to width, storeys and whether the street is designated. This is how the cases compare.
| Side return type | Permitted development? | What it gains | What Chelmsford City Council checks |
|---|---|---|---|
| Single-storey infill, within limits | Often yes, if under half the house width | Full-width kitchen-diner | Width, 4m height, roof glazing |
| Single-storey, over half width | No — full application | Wider room, more light | Boundary treatment, neighbour amenity |
| Two-storey side return | No — full application | Room above as well as below | Bulk, overlooking, terrace rhythm |
| Wraparound (side + rear) | No — full application | L-shaped open-plan ground floor | Combined footprint, garden retained |
In conservation areas such as Boreham Church Road and Boreham Roman Road and Plantation Road, side extensions are not permitted development and always need a full application.
A fixed process built around how Chelmsford City Council validates and decides side-return applications — most drawings are submission-ready within seven days of survey.
Send us your Boreham and The Leighs postcode and terrace type. We confirm your conservation and Article 4 status, whether the infill stays within the side-extension width limit, and score your odds against live Chelmsford City Council decisions.
We measure the side alley, the back-addition wall, floor and eaves levels and the neighbour's window heights — the numbers the width limit, roof pitch and party-wall detailing depend on.
Chartered designers develop the infill and its glazed roof to your brief, drawn inside the permitted-development limits or to Chelmsford City Council's extension guidance, with the boundary and party-wall junction detailed.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Chelmsford City Council issues its decision.
Sometimes not. A single-storey side-return infill can be permitted development if it is no wider than half the original house, no higher than 4 metres, and the property is not on designated land. In Boreham and The Leighs you will need a full application to Chelmsford City Council for anything wider or taller, for a two-storey side return, and for any side extension in a conservation area such as Boreham Church Road and Boreham Roman Road and Plantation Road, where those rights are removed.
It is an infill that fills the narrow open alley running alongside the rear back-addition of a Victorian or Edwardian terrace — the strip of ground that is usually too small to use. Building over it squares off the ground floor, so a cramped galley kitchen becomes a full-width room. Boreham and The Leighs's period terraces are ideally suited to it, which is why the side return is one of the borough's most common extensions. Chelmsford City Council is the decision-maker.
Almost always. A side return is built on or up to the boundary with your neighbour, so the Party Wall etc. Act applies and you must serve notice before work starts — this is entirely separate from Chelmsford City Council's planning decision. We detail the party-wall junction on the drawings and flag the notice early so a surveyor can be appointed without delaying the build. This applies to your Boreham and The Leighs address specifically.
Yes, and it is common — the combined L-shape is a wraparound extension. Once the side infill joins a rear projection beyond the permitted-development depth, the whole thing needs a full householder application to Chelmsford City Council rather than qualifying as permitted development. We draw it as one coherent scheme so the council assesses a single footprint, which reads more clearly than two overlapping proposals. This applies to your Boreham and The Leighs address specifically.
A householder planning application in Boreham and The Leighs runs to a statutory eight-week target, and a lawful development certificate to eight weeks as well, though an incomplete pack can stall at validation. Because a side return involves the boundary and roof glazing, a complete, well-detailed submission matters — we prepare it validation-complete and manage officer queries to keep the decision on track. Chelmsford City Council is the decision-maker.
We price each Boreham and The Leighs side return individually, because alley width and roof form vary house to house, and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until Chelmsford City Council approves, and we confirm at the outset whether your infill is permitted development or needs an application. Call 020 7864 7245 to start.
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