Two-storey extension drawings for Millbay homes — bedroom above, living space below, drawn against the 3-metre projection and 7-metre boundary rules and to Plymouth City Council's design guidance, delivered in days and revised free until your decision.
Plymouth City Council granted 93% of the householder planning decisions it made in its latest published year — 6 points above the 87% England-wide householder average. Millbay is a major regeneration area, so new waterfront development is weighed against the surviving Union Street Victorian frontages and the two conservation areas that flank it, 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.
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 Plymouth City Council needs a full application. Millbay carries at least one Article 4 direction, and conservation areas including Union Street, Stonehouse Peninsula and The Hoe remove those rights outright, so we confirm your exact address before a line is drawn. A validated householder application in Millbay is determined against an 8-week statutory target.
Union Street (the Victorian boulevard laid out to link Plymouth and Devonport, now a conservation area), Millbay Docks (the working ferry port fringed by regeneration-era apartments), West Hoe (Victorian terraces on the limestone slope between Millbay and the Hoe), Bath Street (surviving Victorian streets behind the dock frontage), Rendle Street (close-grained terraces off Union Street) and Stonehouse fringe (the western edge running into the Stonehouse Peninsula) — these are the Millbay pockets our drawings cover most. Heritage designations here include Union Street, Stonehouse Peninsula and The Hoe. Plymouth City Council weighs each proposal against the Plymouth and South West Devon Joint Local Plan (2019), where Union Street's historic role as the ceremonial link between Plymouth and Devonport gives its terraced and commercial frontages protected townscape value. Much of Millbay is already flats — both converted period stock and new-build apartments — which hold no householder permitted-development rights of their own.. On roofs the borough is pitched and parapet roofs on the Victorian terraces and flat and mansard roofs on the newer apartment blocks, over Victorian commercial and terraced frontages along Union Street, new-build waterfront apartment blocks around the docks and converted flats in the surviving period stock.
Adding at first floor changes the question the case officer asks. A single-storey extension is judged mostly on daylight and garden loss; a two-storey extension is judged on overlooking, bulk against the neighbouring roofline, and whether it reads as part of the house or bolted onto it. Millbay is largely Victorian commercial and terraced frontages along Union Street, new-build waterfront apartment blocks around the docks and converted flats in the surviving period stock, and pitched and parapet roofs on the Victorian terraces and flat and mansard roofs on the newer apartment blocks set what a matching roof actually means here.
The permitted-development route exists but is narrow: 3 metres of rear projection, a 7-metre stand-off from the rear boundary, eaves and ridge no higher than the original, and side-facing upper windows obscure-glazed and non-opening below 1.7 metres above floor level. Most two-storey schemes fail one of those, usually the 7-metre boundary rule on a shorter garden, and go in as a full application instead. We establish which route applies before designing, because it changes the drawing set.
Millbay is a major regeneration area, so new waterfront development is weighed against the surviving Union Street Victorian frontages and the two conservation areas that flank it. Millbay adjoins the city-centre streets within Plymouth's HMO Article 4 direction (in force 14 September 2012), which removed the permitted-development right to form a small house in multiple occupation, so a shared-house conversion on this edge needs planning permission.
Some two-storey rear extensions are permitted development. You will need a full application to Plymouth City Council if any of these apply:
We set the projection and boundary distance on the site plan, prove the roof-pitch match on the elevations, and specify obscure glazing on the side windows — the three things Plymouth City Council checks first — then submit a validation-complete pack.
Below is Plymouth City Council's real householder decision record, drawn from official planning statistics and refreshed as new data lands. Plymouth consents the large majority of householder applications around Millbay, where the regeneration context and the Union Street, Stonehouse Peninsula and Hoe conservation areas make townscape and waterfront-setting impact the deciding factors. Two-storey schemes attract more neighbour comment than any other householder work, so the overlooking and daylight case has to be made on the drawings.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
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Across Union Street, Millbay Docks and West Hoe, the schemes that succeed set the first floor back from the ground floor, keep the ridge below the original, and treat the flank wall as blank or obscure-glazed. On victorian commercial and terraced frontages along union street, matching the eaves line matters more than matching the brick: an extension that carries the existing eaves through reads as original even in a different material.
Union Street's historic role as the ceremonial link between Plymouth and Devonport gives its terraced and commercial frontages protected townscape value. We draw the 45-degree daylight test from the neighbour's nearest habitable window, show the window positions in section, and set out the steel and foundation implications early — a two-storey extension changes the load path, so the structural design and the planning design have to be developed together rather than in sequence.
We draw two-storey extensions across Millbay. A few of the areas where they come up most often:
Two storey extension drawings for Union Street — the Victorian boulevard laid out to link Plymouth and Devonport, now a conservation area — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
Two storey extension drawings for Millbay Docks — the working ferry port fringed by regeneration-era apartments — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
Two storey extension drawings for West Hoe — Victorian terraces on the limestone slope between Millbay and the Hoe — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
Two storey extension drawings for Bath Street — surviving Victorian streets behind the dock frontage — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
Two storey extension drawings for Rendle Street — close-grained terraces off Union Street — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
Two storey extension drawings for Stonehouse fringe — the western edge running into the Stonehouse Peninsula — dimensioned against the 3m and 7m limits and drawn to Plymouth City Council's guidance.
The first-floor limits are tighter than the ground-floor ones. This is how the common cases compare.
| Scheme | Permitted development? | Deciding limit | What Plymouth City Council checks |
|---|---|---|---|
| Two-storey rear, 3m projection, 7m+ to boundary | Often yes | 3m projection / 7m boundary | Roof match, side-window glazing |
| Two-storey rear, under 7m to boundary | No — full application | Rear-boundary distance | Overlooking, daylight, garden loss |
| Two-storey side extension | No — full application | Side elevation | Gap to boundary, street rhythm |
| Two-storey wraparound | No — full application | Combined footprint | Bulk, massing, neighbour amenity |
| Any two-storey on designated land | No — full application | Designation | Character and appearance |
Limits from the GPDO 2015, Schedule 2, Part 1, Class A — two-storey rear extension conditions.
A fixed process built around how Plymouth City Council validates and decides two-storey applications.
Send us your Millbay postcode and garden depth. We measure the 7-metre boundary rule against your plot, confirm designation status, and score your odds against live Plymouth City Council decisions.
We measure the original rear wall, eaves and ridge heights, garden depth and every neighbouring window that faces the site — the inputs the daylight and overlooking case is built from.
Chartered designers develop the two-storey addition to your brief with the roof and eaves resolved, and we coordinate the load path so the structural scheme and the planning scheme are the same building.
We submit the application, manage validation and case-officer queries, and revise the drawings free until Plymouth City Council issues its decision.
Often, but not always. A two-storey rear extension can be permitted development if it projects no more than 3 metres, sits at least 7 metres from the rear boundary, does not exceed the existing eaves and ridge, and has obscure-glazed non-opening side windows below 1.7 metres. In Millbay, the 7-metre rule is what most commonly forces a full application to Plymouth City Council.
No part of a permitted-development two-storey rear extension may come within 7 metres of the boundary opposite the rear wall of the house. It exists to protect the neighbour behind you from being overlooked at first floor. On shorter Millbay gardens this is decisive, and we measure it on survey before any design work rather than discovering it at validation. Plymouth City Council is the decision-maker.
Not under permitted development — two-storey side extensions always need a full application to Plymouth City Council. They are assessed on the gap to the boundary, whether the street's rhythm of spaces between houses survives, and whether the extension is subordinate to the original. Setting the first floor back from the front building line and down from the ridge is what usually makes the difference. This applies to your Millbay address specifically.
Overlooking is the most common objection, and it is answerable on the drawings. We position habitable-room windows away from neighbouring gardens, obscure-glaze and fix shut anything on the flank below 1.7 metres, and show the sight lines in section. Where the geometry is tight, a rooflight or a high-level window gives the same daylight without the mutual overlooking that draws objections. This applies to your Millbay address specifically. Plymouth City Council is the decision-maker.
Almost certainly. Excavating within 3 metres of a neighbouring structure and building on or up to the boundary both trigger the Party Wall etc. Act 1996, and a two-storey extension usually does both. It is entirely separate from Plymouth City Council's planning decision, so we flag the notice period early and detail the junction on the drawings. This applies to your Millbay address specifically.
Yes. Adding a floor changes the load path from roof to foundation, so beams, padstones and foundation depths all need designing and calculating for building control. Planning and building regulations are separate consents, and the structural set is what building control assesses — we prepare both so the approved scheme is the buildable one. This applies to your Millbay address specifically. Plymouth City Council is the decision-maker.
We quote each Millbay two-storey extension individually, because plot depth, roof form and structural complexity vary house to house, and send a fixed, no-obligation quote within one working day. It covers the drawing pack with free revisions until Plymouth City Council approves. Call 020 7864 7245 to start.
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