Orangery and conservatory drawings for Southsea homes — checked against the Class A rear limits and the 30m² building-regulations exemption, drawn to Portsmouth City Council's guidance and revised free until your decision.
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. Extreme island density means there is little room to build outward, so most schemes are pushed into the rear and the roof and are judged against tightly packed neighbours, which is where a policy-literate drawing pack earns its keep. Its dominant Georgian (1714–1837), Victorian (1837–1901), Edwardian (1901–1910), interwar (1918–1939) and postwar (1945–1970) housing stock sets the design brief on most streets.
Class A and Class B set the thresholds — a rear dormer to 40m³ on a terrace or 50m³ on a semi or detached, and a single-storey rear extension to 3m on a terrace or 4m on a detached house — beyond which Portsmouth City Council needs a full application. Southsea carries at least one Article 4 direction, and conservation areas including Owen's Southsea, Castle Road and King Street remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Southsea is determined against an 8-week statutory target.
Owen's Southsea (Thomas Ellis Owen's mid-Victorian stucco villas around Queens Crescent), Castle Road (fine-grained Regency and early-Victorian terraces near the Common), Elm Grove (grand Victorian terraces along the spine toward the seafront), Albert Road (the shopping and cafe strip fronted by tall Victorian houses), Somers Town (postwar and interwar estate housing on the northern edge) and Kings Road (Victorian terraces and mansion flats near Palmerston Road) — these are the Southsea pockets our drawings cover most. Heritage designations here include Owen's Southsea, Castle Road, King Street, Stanley Street and The Terraces. Portsmouth City Council weighs each proposal against the Portsmouth Local Plan and the council's Houses in Multiple Occupation SPD, where the city-wide Article 4 direction and the HMO SPD steer student-let conversions near the University through full planning control. Much of central Southsea has already been split into converted flats and maisonettes, which carry no householder permitted-development rights of their own.. On roofs the borough is pitched slate roofs on the bay-fronted terraces and shallow parapet and valley roofs behind Owen's stucco frontages, over Thomas Ellis Owen's stucco villas and terraces, bay-fronted Victorian and Edwardian terraces and converted flats and maisonettes.
The difference is not marketing. A conservatory is predominantly glazed — at least three quarters of the roof and half of the walls — which is what earns it the building-regulations exemption. An orangery has a solid masonry perimeter with a glazed lantern set into a flat roof, so it usually reads as a conventional extension for building control and has to meet Part L thermal standards, Part A structure and Part B fire like any other room.
Both are judged the same way for planning: as rear extensions, against the Class A depth, height and eaves limits, and against the Portsmouth Local Plan and the council's Houses in Multiple Occupation SPD. Southsea is largely Thomas Ellis Owen's stucco villas and terraces, bay-fronted Victorian and Edwardian terraces and converted flats and maisonettes, and the design question is usually whether the glazing reads as a lightweight addition to that stock or as a bolted-on conservatory kit. On period houses, an orangery with a properly proportioned lantern almost always sits better than a full-height glazed box.
In conservation areas such as Owen's Southsea and Castle Road, rear glazing is assessed on visibility from the street and on the effect on the rear elevation's character. Portsmouth operates a city-wide Article 4 direction removing permitted-development rights for the change of family houses to small (C4) houses in multiple occupation, so on Southsea's dense terraced streets near the University any HMO conversion needs a full planning application rather than being automatic.
Many conservatories are permitted development. You will need an application to Portsmouth City Council where any of these apply:
We check the scheme against the Class A planning limits and against the building-regulations exemption at the same time, so you know before committing whether you are building an exempt conservatory or a fully regulated room.
Below is Portsmouth City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Portsmouth consents roughly seven or eight in ten householder schemes, but on Southsea's stucco villa streets and packed terraces the deciding issues are heritage grain, HMO saturation and the sheer proximity of neighbours. Glazed rear additions are judged on depth, eaves height and how the glazing meets the existing elevation.
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 Owen's Southsea, Castle Road and Elm Grove, the schemes that succeed keep the eaves below the neighbour's ground-floor cill line, set the glazing back from the boundary, and use a solid parapet or brick perimeter to tie the addition into the house. On thomas ellis owen's stucco villas and terraces, a lantern set in a flat roof usually reads better than a pitched glazed roof, and it avoids the summer overheating that makes full conservatories unusable for months a year.
Extreme island density means there is little room to build outward, so most schemes are pushed into the rear and the roof and are judged against tightly packed neighbours. The decision worth making early is whether to keep the separating doors. Keeping them preserves the building-regulations exemption but leaves you with a room that is not part of the house; removing them creates one continuous space but brings the whole addition inside Part L, which changes the glazing specification and usually the heating design too. We set out both versions before you commit.
We draw glazed rear additions across Southsea. A few of the areas where they come up most often:
Orangery and conservatory drawings for Owen's Southsea — Thomas Ellis Owen's mid-Victorian stucco villas around Queens Crescent — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
Orangery and conservatory drawings for Castle Road — fine-grained Regency and early-Victorian terraces near the Common — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
Orangery and conservatory drawings for Elm Grove — grand Victorian terraces along the spine toward the seafront — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
Orangery and conservatory drawings for Albert Road — the shopping and cafe strip fronted by tall Victorian houses — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
Orangery and conservatory drawings for Somers Town — postwar and interwar estate housing on the northern edge — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
Orangery and conservatory drawings for Kings Road — Victorian terraces and mansion flats near Palmerston Road — checked against the Class A limits and drawn to Portsmouth City Council's guidance.
The planning test is the same for both. The building-regulations test is not.
| Structure | Planning route | Building regulations | Practical effect |
|---|---|---|---|
| Conservatory under 30m², doors retained | Class A rear extension limits | Largely exempt | Cheaper build, unheated in winter |
| Conservatory, doors removed | Class A rear extension limits | Part L applies in full | Continuous space, higher spec glazing |
| Orangery with solid perimeter and lantern | Class A rear extension limits | Fully regulated | Usable year round, better on period houses |
| Any of the above beyond the depth limits | Full householder application | As above | 8-week determination |
| Any of the above on designated land | Full householder application | As above | Design and visibility assessed |
Planning limits from the GPDO 2015, Schedule 2, Part 1, Class A; exemption criteria from the Building Regulations 2010, Schedule 2, Class 7.
A fixed process covering both consents, because they pull in different directions.
Send us your Southsea postcode and house type. We confirm the Class A limits that apply, check designation status, and score your odds against live Portsmouth City Council decisions.
We measure the rear elevation, eaves and ground levels, and the neighbouring boundary — the numbers that decide both the projection limit and the 2-metre eaves rule.
Chartered designers develop the orangery or conservatory to your brief, and we set out clearly whether it stays inside the building-regulations exemption or becomes a fully regulated room.
We submit the certificate or application, manage validation and officer queries, and revise free until Portsmouth City Council decides.
Often not. A conservatory is treated as a rear extension, so it can be permitted development within the Class A limits — 3 metres of projection on a terrace or semi, 4 metres on a detached house, with eaves under 3 metres where it sits within 2 metres of a boundary. In Southsea you will need an application to Portsmouth City Council beyond those limits, and on designated land such as Owen's Southsea and Castle Road.
A conservatory is largely exempt if it is under 30 square metres, at ground level, separated from the house by external-quality doors, and has at least 75% of its roof and 50% of its walls glazed. Glazing, electrics and any drainage work still have to comply. Remove the separating doors and the exemption falls away — the space becomes part of the house and Part L thermal standards apply. This applies to your Southsea address specifically. Portsmouth City Council is the decision-maker.
For planning, none — both are rear extensions assessed against the same Class A limits by Portsmouth City Council. The difference is in building control: an orangery's solid perimeter and flat roof with a lantern usually means it fails the glazing test for exemption, so it is fully regulated. That is why an orangery costs more to build but is comfortable in January. This applies to your Southsea address specifically.
Usually yes at the rear, though permitted-development rights are narrower on designated land and an Article 4 direction can remove them entirely. The assessment turns on whether the addition is visible from the street and how it meets the original rear elevation. A restrained orangery in matching brick with a lantern is consistently easier to get through than a proprietary glazed conservatory. This applies to your Southsea address specifically. Portsmouth City Council is the decision-maker.
A fully glazed roof will, unless it is specified for it. That is the practical reason most of our clients end up building an orangery instead: a solid insulated roof perimeter with a lantern gives daylight without the greenhouse effect, and keeps the space usable across the year. We raise it at design stage because it is much cheaper to solve on paper than after the build. This applies to your Southsea address specifically. Portsmouth City Council is the decision-maker.
If you excavate foundations within 3 metres of a neighbouring structure and deeper than its foundations, or build on the boundary itself, the Party Wall etc. Act 1996 applies and notice must be served. That is separate from Portsmouth City Council's planning decision. We flag it at design stage so the notice period does not delay the start on site. This applies to your Southsea address specifically.
We quote each Southsea orangery or conservatory individually, because the structure and the roof form change the work considerably, and send a fixed, no-obligation quote within one working day. It covers the full drawing pack with free revisions until Portsmouth City Council approves. Call 020 7864 7245 to start.
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