Single-storey, double-storey, rear and side extension drawings for Old Portsmouth homes — measured to Portsmouth City Council's design guidance, delivered in days and revised free until your decision, with a free approval-odds check before you commit.
Portsmouth City Council granted 88% of the householder planning decisions it made in its latest published year — 1 point above the 87% England-wide householder average. Old Portsmouth is the city's original walled settlement, so alterations are measured against surviving Georgian and pre-Georgian fabric, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837) 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. Old Portsmouth carries at least one Article 4 direction, and conservation areas including Old Portsmouth and Gunwharf remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Old Portsmouth is determined against an 8-week statutory target.
The Point (cobbled Spice Island lanes of historic cottages by the harbour mouth), High Street (Georgian town houses around the Cathedral), Broad Street (the narrow spine down to the Round Tower and Point), Grand Parade (formal Georgian frontages beside the fortifications), Gunwharf (the former ordnance yard, now waterfront apartments and quays) and Old Portsmouth Ramparts (houses set against the Hotwalls and sea defences) — these are the Old Portsmouth pockets our drawings cover most. Heritage designations here include Old Portsmouth and Gunwharf. Portsmouth City Council weighs each proposal against the Portsmouth Local Plan and the council's Houses in Multiple Occupation SPD, where the tight historic street pattern leaves almost no room to extend outward, concentrating change on roofs and rear yards. Much of Gunwharf and parts of the old town are flats and apartment conversions, which carry no householder permitted-development rights.. On roofs the borough is pitched tile and slate roofs on the town houses and parapet roofs on the taller Georgian frontages, over Georgian and Georgian-revival town houses, historic cottages around The Point and waterfront apartment conversions.
Old Portsmouth homes come in a handful of recurring shapes, and each one points to a different extension. The borough is built largely from Georgian and Georgian-revival town houses, historic cottages around The Point and waterfront apartment conversions, 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. Portsmouth City Council judges every one of them against the Portsmouth Local Plan and the council's Houses in Multiple Occupation SPD, 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. Old Portsmouth is the city's original walled settlement, so alterations are measured against surviving Georgian and pre-Georgian fabric, so we design around it from the first sketch rather than discover it at validation.
Old Portsmouth also protects whole streets — Old Portsmouth and Gunwharf among them. Portsmouth's city-wide Article 4 direction removes permitted-development rights for small HMO conversions here as well, and in the historic core of Old Portsmouth even minor external works are tightly controlled by conservation-area policy. 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 Old Portsmouth 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 Portsmouth 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 Portsmouth 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 Portsmouth City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Portsmouth approves a healthy share of householder work in Old Portsmouth, but the historic core's Georgian fabric and cramped plots make heritage sensitivity the decisive factor. 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 The Point, High Street and Broad Street, 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 georgian and georgian-revival town houses, a side-return infill frequently pairs with it to square off the plan; on wider waterfront apartment conversions, a two-storey side or rear extension can add a bedroom above without swallowing the garden.
The tight historic street pattern leaves almost no room to extend outward, concentrating change on roofs and rear yards. 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 Portsmouth 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 Old Portsmouth projects come up most often:
Extension drawings for The Point's cobbled Spice Island lanes of historic cottages by the harbour mouth — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
Extension drawings for High Street's Georgian town houses around the Cathedral — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
Extension drawings for Broad Street's the narrow spine down to the Round Tower and Point — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
Extension drawings for Grand Parade's formal Georgian frontages beside the fortifications — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
Extension drawings for Gunwharf's the former ordnance yard, now waterfront apartments and quays — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
Extension drawings for Old Portsmouth Ramparts's houses set against the Hotwalls and sea defences — footprint-checked, daylight-tested and drawn to Portsmouth City Council's guidance.
The right extension in Old Portsmouth 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 Portsmouth 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 Old Portsmouth and Gunwharf and Article 4 directions can remove permitted-development rights.
A fixed process built around how Portsmouth City Council validates and decides householder extension applications — most drawings are submission-ready within seven days of survey.
Tell us your Old Portsmouth 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 Portsmouth 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 Portsmouth 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 Portsmouth 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 Old Portsmouth you will need to apply to Portsmouth 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 Old Portsmouth and Gunwharf.
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 Portsmouth City Council and a neighbour-consultation period, and it does not apply on designated land such as Old Portsmouth'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 Portsmouth 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 Old Portsmouth address specifically.
A householder planning application in Old Portsmouth 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. Portsmouth 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 Portsmouth City Council's building control or an approved inspector can sign the work off. This applies to your Old Portsmouth address specifically.
Every house and brief is different, so we price each Old Portsmouth extension individually and send a fixed, no-obligation quote back within one working day. It covers the full drawing pack with free revisions until Portsmouth City Council approves, and we tell you upfront whether your extension qualifies as permitted development. Call 020 7864 7245 to get started.
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.