Single-storey, double-storey, rear and side extension drawings for Boreham and The Leighs homes — measured to Chelmsford City Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
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.
Boreham and The Leighs homes come in a handful of recurring shapes, and each one points to a different extension. 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%), so a Victorian terrace usually wants a rear or side-return infill, while an interwar semi has room for a wider single-storey wrap or a two-storey side addition. Chelmsford City Council judges every one of them against the adopted Chelmsford local plan and Chelmsford City Council's design guidance for householder work, weighing footprint, height and the impact on the house next door before it looks at the elevations.
That is why the drawings decide the outcome. We set the extension depth against the permitted-development limits precisely, keep the eaves and ridge within the allowances, and plot the 45-degree daylight lines to the neighbours' windows so the case officer can see the amenity test is passed. 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 design around it from the first sketch rather than discover it at validation.
Boreham and The Leighs also protects whole streets — Boreham Church Road and Boreham Roman Road and Plantation Road among them. 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 designated land the larger-home extension route and most side extensions stop being permitted development, so we confirm your address against those layers before drawing a line.
Plenty of Boreham and The Leighs extensions are permitted development and need no planning application — a single-storey rear extension within the depth and height limits is the common case. You will normally need to apply to Chelmsford City Council if any of these apply:
We draw the footprint, the ridge and eaves heights and the neighbours' daylight on the page — the relationships Chelmsford City Council's officers weigh first — and submit a validation-complete pack, whether that is a lawful development certificate, a prior-approval notification 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. A complete, policy-literate extension pack anticipates those pressure points before submission, which is why professionally drawn applications are decided faster and refused less often than DIY ones.
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 extension that lands most often is the single-storey rear addition — a glazed kitchen-diner across the back of the house, kept within the permitted-development depth or taken to a full application where the ground floor wants more. On the borough's 2000s houses and apartments (15% of 3,080 homes), a side-return infill frequently pairs with it to square off the plan; on wider late-1960s and early-1970s houses (13%), a two-storey side or rear extension can add a bedroom above without swallowing the garden.
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 size the extension to the amenity and daylight tests, match the roof and materials to the host house, and keep enough garden to satisfy Chelmsford City Council's space standards — so the scheme answers the borough's questions before an objection can raise them. Where permitted-development rights are used up or removed, we prepare the householder application to the council's extension design guidance instead.
We draw extensions on every street in the borough. A few of the neighbourhoods where Boreham and The Leighs projects come up most often:
Extension drawings for Boreham Church Road's conservation area designated in 1981 — footprint-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Extension drawings for Boreham Roman Road and Plantation Road's conservation area designated in 1987 — footprint-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Extension drawings for Great and Little Leighs's civil parish within Boreham and The Leighs — footprint-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Extension drawings for Boreham's civil parish within Boreham and The Leighs — footprint-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Extension drawings for Chelmsford Garden's civil parish within Boreham and The Leighs — footprint-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
The right extension in Boreham and The Leighs depends on your house type and how much garden you can give up. This is how the main options compare on planning route and what they add.
| Extension type | Permitted development? | What it adds | What Chelmsford City Council checks |
|---|---|---|---|
| Single-storey rear | Often, within 3m/4m depth (6m/8m via prior approval) | Bigger kitchen-diner across the back | Depth, height, neighbour daylight (45°) |
| Side-return infill | Sometimes, if within width and height limits | Squares off an L-shaped ground floor | Width vs the original house, glazing to boundary |
| Two-storey rear/side | No — full application | Extra bedroom or bathroom above | Bulk, overlooking, 7m rear-boundary gap |
| Wraparound (rear + side) | No — full application | Whole-width open-plan ground floor | Combined footprint and garden retained |
Route depends on your street — conservation areas such as Boreham Church Road and Boreham Roman Road and Plantation Road and Article 4 directions can remove permitted-development rights.
A fixed process built around how Chelmsford City Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your Boreham and The Leighs postcode and house type. We confirm your conservation and Article 4 status, how much permitted-development depth you have left, and score your odds against live Chelmsford City Council decisions.
We measure the existing footprint, floor and eaves levels, boundary distances and the neighbours' window positions — the numbers the depth limits and daylight tests depend on.
Chartered designers develop the single-storey, two-storey or side extension to your brief, drawn inside the permitted-development limits or to Chelmsford City Council's extension design guidance.
We submit the certificate, prior-approval notice or application, manage validation and case-officer queries, and revise the drawings free until Chelmsford City Council issues its decision.
Not always. A single-storey rear extension up to 3 metres deep on a terrace or semi, or 4 metres on a detached house, and no higher than 4 metres, is usually permitted development. In Boreham and The Leighs you will need to apply to Chelmsford City Council for two-storey extensions, side extensions wider than half the house, anything forward of the front wall, deeper rear extensions under the larger-home prior-approval route, and any extension in a conservation area such as Boreham Church Road and Boreham Roman Road and Plantation Road.
Standard permitted development allows 3 metres on a terraced or semi-detached house and 4 metres on a detached one. The larger-home extension scheme can double that to 6 or 8 metres, but it needs a prior-approval notification to Chelmsford City Council and a neighbour-consultation period, and it does not apply on designated land such as Boreham and The Leighs's conservation areas. We confirm which route your property qualifies for before drawing.
Two-storey and double-storey extensions almost always need a full householder application to Chelmsford City Council, because they fall outside permitted development on most homes. The council looks closely at bulk, overlooking of neighbours and the 7-metre gap a two-storey rear extension must keep from the rear boundary. We design to those tests and show the daylight and privacy angles on the drawings. 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, a larger-home prior-approval notification to around six weeks including the neighbour-consultation period, and a lawful development certificate to eight weeks. Incomplete submissions stall at validation, so we submit a complete pack and manage officer queries to keep the decision on schedule. Chelmsford City Council is the decision-maker.
Yes — planning permission and building regulations are separate consents, and almost every extension needs both. Planning governs whether you can build it; building control governs how it is built, covering structure, insulation, drainage and fire safety. We prepare the building-regulations drawings alongside the planning set so Chelmsford City Council's building control or an approved inspector can sign the work off. This applies to your Boreham and The Leighs address specifically.
Every house and brief is different, so we price each Boreham and The Leighs extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Chelmsford City Council approves, and we tell you upfront whether your extension qualifies as permitted development. Call 020 7864 7245 to get started.
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