Back-of-house extension drawings for Boreham and The Leighs homes — the glazed kitchen-diner across the rear, drawn to Chelmsford City Council's depth and daylight limits, 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 rear extension is the workhorse of Boreham and The Leighs home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because 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%), most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what Chelmsford City Council scrutinises. The council reads the proposal against the adopted Chelmsford local plan and Chelmsford City Council's design guidance for householder work, and the first line an officer draws is the 45-degree splay from the neighbour's nearest window.
So the drawings live or die on geometry. We set the depth against the exact permitted-development figure, hold the eaves and the flat-roof or lantern build-up under the 4-metre height ceiling, and show the projection tested against both the 45-degree plan angle and the 25-degree section angle to the neighbouring windows. 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 the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Boreham Church Road and Boreham Roman Road and Plantation Road among Boreham and The Leighs's — the larger-home extension route is switched off and even a modest rear addition needs consent. 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 the survey.
Many single-storey rear extensions in Boreham and The Leighs are permitted development and need no application. You will normally need to apply to Chelmsford City Council, or use the larger-home prior-approval route, if any of these apply:
We draw the depth, the roof build-up and the daylight splays to each neighbour on the page — the tests Chelmsford City Council's officers apply first — and submit a validation-complete pack, whether that is a lawful development certificate, a larger-home prior-approval notice or a full householder application.
Below is Chelmsford City Council's real householder decision record, taken 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. Rear extensions turn most often on neighbour daylight and depth, so a drawing pack that proves those tests 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 rear extension is typically a single-storey glazed box within the depth limit, roofed either flat with a lantern or in a shallow mono-pitch, and finished in brick or render to match the host wall. On the borough's 2000s houses and apartments (15% of 3,080 homes), keeping the projection to the permitted-development figure often avoids an application entirely; where owners want the full 6 metres, the larger-home route succeeds when the neighbour-consultation period passes without a sustained objection.
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 extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth Chelmsford City Council expects — so the back elevation answers the amenity case before a neighbour can lodge one. Two-storey rear extensions we draw with the 7-metre boundary gap and privacy screening resolved on the plan.
We draw rear extensions on every street in the borough. A few of the neighbourhoods where Boreham and The Leighs back-of-house projects come up most often:
Rear extension drawings for Boreham Church Road's conservation area designated in 1981 — depth-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Rear extension drawings for Boreham Roman Road and Plantation Road's conservation area designated in 1987 — depth-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Rear extension drawings for Great and Little Leighs's civil parish within Boreham and The Leighs — depth-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Rear extension drawings for Boreham's civil parish within Boreham and The Leighs — depth-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
Rear extension drawings for Chelmsford Garden's civil parish within Boreham and The Leighs — depth-checked, daylight-tested and drawn to Chelmsford City Council's guidance.
How far you can extend at the back in Boreham and The Leighs depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What Chelmsford City Council checks |
|---|---|---|---|
| Standard permitted development | 3m terrace/semi · 4m detached | Lawful development certificate (optional) | Depth, 4m height, materials |
| Larger-home prior approval | 6m terrace/semi · 8m detached | Prior-approval notice + neighbour consultation | Neighbour objections on amenity |
| Full householder application | Beyond the above, or two-storey | Full planning permission | Daylight (45°/25°), bulk, garden retained |
| Conservation area | Case by case | Full planning permission | Character, roof form, boundary treatment |
The larger-home route is switched off on designated land — conservation areas such as Boreham Church Road and Boreham Roman Road and Plantation Road and Article 4 streets need a full application.
A fixed process built around how Chelmsford City Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your Boreham and The Leighs postcode and house type. We confirm your conservation and Article 4 status, how much rear-extension depth you have under permitted development, and score your odds against live Chelmsford City Council decisions.
We measure the original rear wall, floor and eaves levels, side and rear boundary distances and the neighbours' window positions — the numbers the depth limit and daylight splays depend on.
Chartered designers develop the single or two-storey rear extension to your brief, drawn inside the permitted-development limits or to Chelmsford City Council's extension design guidance, with the daylight angles shown.
We submit the certificate, prior-approval notice or application, handle validation and case-officer queries, and revise the drawings free until Chelmsford City Council issues its decision.
Often not. 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 involve Chelmsford City Council for anything deeper via the larger-home route, for two-storey rear extensions, and for any rear extension in a conservation area such as Boreham Church Road and Boreham Roman Road and Plantation Road, where those permitted-development rights fall away.
The larger-home extension scheme lets a single-storey rear extension reach 6 metres on a terrace or semi, or 8 metres on a detached house — double the standard allowance. It is not automatic: you submit a prior-approval notification to Chelmsford City Council, neighbours are consulted, and if one objects on amenity grounds the council rules on it. It also does not apply on designated land such as Boreham and The Leighs's conservation areas.
It is the daylight test Chelmsford City Council applies to protect neighbours. Drawn on plan, a line at 45 degrees from the midpoint of the neighbour's nearest ground-floor window should not be crossed by your extension; a companion 25-degree line is checked in section. If the projection breaches it, the extension is likely to be shortened or refused, so we test and prove it on the drawings before submission. This applies to your Boreham and The Leighs address specifically.
A two-storey rear extension almost always needs a full householder application to Chelmsford City Council, as it sits outside permitted development on most homes. The council checks that it stays at least 7 metres from the rear boundary, does not overbear the neighbours and avoids new overlooking. We resolve the boundary gap, privacy and daylight on the plans so the application is decided on its merits. This applies to your Boreham and The Leighs address specifically.
Frequently, yes. If the rear extension involves work to a shared wall, building up to the boundary, or excavating foundations near a neighbour's structure, the Party Wall etc. Act applies and you must serve notice — this is separate from Chelmsford City Council's planning decision. We flag it early and can prepare the drawings a party-wall surveyor needs alongside the planning set. This applies to your Boreham and The Leighs address specifically.
We price each Boreham and The Leighs rear extension on its own footprint 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 extension is permitted development, needs prior approval, or a full application. Call 020 7864 7245 to begin.
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.