Back-of-house extension drawings for Petersfield homes — the glazed kitchen-diner across the rear, drawn to Cambridge City Council's depth and daylight limits, delivered in days and revised free until your decision, with a free approval-odds check first.
Cambridge 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. The tight party-wall spacing of the artisan terraces controls the scale of rear and side additions, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901) 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. Petersfield carries at least one Article 4 direction, and conservation areas including Mill Road, The Kite and New Town and Glisson Road remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Petersfield is determined against an 8-week statutory target.
Gwydir Street (1860s artisan terraces, home to the Arts-and-Crafts David Parr House), Mill Road (the Victorian shopping street at the heart of the conservation area), Sturton Town (close-packed terraces built on land bought by developer Sturton), Norfolk Street (college-named terraces developed by Gonville and Caius and Corpus Christi) and Petersfield green (terraces facing directly onto the pavement around the green) — these are the Petersfield pockets our drawings cover most. Heritage designations here include Mill Road, The Kite and New Town and Glisson Road. Cambridge City Council weighs each proposal against the Cambridge Local Plan 2018 and the emerging Greater Cambridge Local Plan, where roof dormers are held to the unbroken slate rooflines that define the Mill Road character. Converted flats and student lets are widespread across the Mill Road terraces, and none of them hold householder permitted-development rights.. On roofs the borough is pitched slate roofs on the Victorian terraces and shallow-pitched roofs behind the Mill Road frontages, over dense Victorian artisan and railway-worker terraces, late-Victorian college-owned terraces and converted period flats.
The rear extension is the workhorse of Petersfield home improvement — it is how a dark back kitchen becomes an open family room facing the garden. Because the borough is built largely from dense Victorian artisan and railway-worker terraces, late-Victorian college-owned terraces and converted period flats, most back walls sit close to a neighbour on at least one side, and that proximity, not the design, is what Cambridge City Council scrutinises. The council reads the proposal against the Cambridge Local Plan 2018 and the emerging Greater Cambridge Local Plan, 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. The tight party-wall spacing of the artisan terraces controls the scale of rear and side additions, so the rear elevation is composed around it rather than corrected after an objection.
Where the property sits in a conservation area — Mill Road, The Kite and New Town and Glisson Road among Petersfield's — the larger-home extension route is switched off and even a modest rear addition needs consent. Petersfield lies within the Mill Road conservation area — designated in 1993 and covering the streets on the west side of the railway — with The Kite and New Town and Glisson Road adjoining, all subject to Article 4 controls on permitted development. We confirm the designation before the survey.
Many single-storey rear extensions in Petersfield are permitted development and need no application. You will normally need to apply to Cambridge 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 Cambridge 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 Cambridge City Council's real householder decision record, taken from official planning statistics and refreshed as new data lands. Cambridge approves around 90% of applications, but in Petersfield the dense terrace grain and the Mill Road conservation area shape what can realistically be built. 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 Gwydir Street, Mill Road and Sturton Town, 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 dense victorian artisan and railway-worker terraces, 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.
Roof dormers are held to the unbroken slate rooflines that define the Mill Road character. We keep the extension inside the daylight splays, set any glazed roof below the first-floor cill, and retain the garden depth Cambridge 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 Petersfield back-of-house projects come up most often:
Rear extension drawings for Gwydir Street's 1860s artisan terraces, home to the Arts-and-Crafts David Parr House — depth-checked, daylight-tested and drawn to Cambridge City Council's guidance.
Rear extension drawings for Mill Road's the Victorian shopping street at the heart of the conservation area — depth-checked, daylight-tested and drawn to Cambridge City Council's guidance.
Rear extension drawings for Sturton Town's close-packed terraces built on land bought by developer Sturton — depth-checked, daylight-tested and drawn to Cambridge City Council's guidance.
Rear extension drawings for Norfolk Street's college-named terraces developed by Gonville and Caius and Corpus Christi — depth-checked, daylight-tested and drawn to Cambridge City Council's guidance.
Rear extension drawings for Petersfield green's terraces facing directly onto the pavement around the green — depth-checked, daylight-tested and drawn to Cambridge City Council's guidance.
How far you can extend at the back in Petersfield depends on your house type and the route you take. This is how the options compare.
| Route | Depth allowed | Consent needed | What Cambridge 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 Mill Road and The Kite and Article 4 streets need a full application.
A fixed process built around how Cambridge City Council validates and decides rear-extension applications — most drawings are submission-ready within seven days of survey.
Send us your Petersfield 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 Cambridge 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 Cambridge 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 Cambridge 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 Petersfield. You will need to involve Cambridge 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 Mill Road and The Kite, 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 Cambridge 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 Petersfield's conservation areas.
It is the daylight test Cambridge 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 Petersfield address specifically.
A two-storey rear extension almost always needs a full householder application to Cambridge 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 Petersfield 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 Cambridge 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 Petersfield address specifically.
We price each Petersfield 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 Cambridge 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.