Flat Conversion Drawings in Greenwich
Fixed-fee, MCIAT-chartered flat conversion drawings for Greenwich homeowners — Royal Borough of Greenwich validation and local constraints handled from the start.
Greenwich stretches from the Georgian streets of West Greenwich and the Georgian-fringed heath at Blackheath — set against the Maritime Greenwich World Heritage Site — out to the Edwardian villas of Westcombe Park and the interwar and post-war suburbs of Eltham and Kidbrooke. The northern, historic core carries strong conservation and protected-view control, while the outer suburbs and newer riverside development along the Thames offer more generous plots for extensions and lofts. The right route depends heavily on where in the borough you are.
The character shifts street by street. Conservation areas at West Greenwich, Ashburnham Triangle, Blackheath, Westcombe Park, Eltham Park and Woolwich each carry design control over materials, rooflines and front elevations, and the sloping sites around Blackheath and the Greenwich hills shape what an extension can be. Protected views toward the Royal Observatory and across the river, together with Article 4 directions on HMO conversions in parts of the borough, mean the constraints on a heritage-led scheme in the historic core differ sharply from a straightforward suburban addition toward Eltham or Charlton.
We prepare Greenwich planning drawings tuned to the specific area — heritage-led applications around West Greenwich and Blackheath, and simpler extension and loft schemes toward Eltham and Kidbrooke — confirming the World Heritage Site setting and conservation designations for your address first. It is the same council-accepted drawing set an architect would prepare, usually at around 30% less, with a fixed fee agreed up front, a roughly seven-day drawing turnaround and free redraws until the Royal Borough of Greenwich approves. Most householder applications are decided within the statutory eight-week period once validated, so we draw to the council's validation checklist from the start.
Planning in Greenwich: what to know before you apply
A distinctive Greenwich consideration is the Maritime Greenwich World Heritage Site and its buffer zone, where the council protects townscape and long views toward the Royal Observatory — proposals nearby are assessed against that setting. Conservation-area control in West Greenwich, Blackheath and Westcombe Park, and Article 4 directions on HMO conversions in parts of the borough, also apply. We confirm what affects your address before drawing.
Typical Greenwich housing stock
Georgian and early-Victorian terraces around West Greenwich and Blackheath, Edwardian villas in Westcombe Park, interwar and post-war housing toward Eltham and Kidbrooke, and newer riverside development along the Thames.
Areas we regularly draw for in Greenwich
Greenwich · Blackheath · Westcombe Park · Charlton · Woolwich · Eltham · Kidbrooke
What the numbers say about Greenwich planning decisions
These are Royal Borough of Greenwich’s own reported figures, published by government rather than estimated by us. They are what we design against — a borough that refuses one householder application in five needs a different drawing package from one that refuses one in twenty.
Proving lawfulness in Greenwich
Certificates of lawful development and prior-approval outcomes decided by Royal Borough of Greenwich over eight quarters.
| Certificates of lawful development decided | 839 |
|---|---|
| Larger extensions cleared without a full application | 0 |
| Prior approval refused | 126 |
Source: Ministry of Housing, Communities and Local Government (PS1 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.
If Royal Borough of Greenwich refuses: appeal outcomes
Planning appeals against Royal Borough of Greenwich determined by the Planning Inspectorate, 2021–2026. Enforcement notices and withdrawn cases are excluded.
| Appeals determined | 635 |
|---|---|
| Allowed | 237 |
| Dismissed | 398 |
| Householder appeals allowedFrom 344 householder appeals. England average 36% | 46% |
Source: Planning Inspectorate appeals casework. Open Government Licence v3.0 Extracted 2026-08-16.
Flat Conversion Drawings for Greenwich homes: the package and the process
Converting a house into flats is drawn unit by unit. Each proposed flat needs its layout, its floor area, its own entrance arrangement and its amenity provision shown, along with refuse and cycle storage that meets the standards the council applies to new residential units.
The separation between units is the technical core: floors and walls detailed for fire resistance and sound insulation, a common escape route drawn and protected, and services routed without breaching the compartments. Those details go on the drawings because Building Control assesses them there, not on site.
Conversion suits buildings with the plan depth and stair position to make two workable units. A wide terrace or a large semi can usually be split without landlocking a room, while a narrow plan often cannot give both units light, access and separation at the same time.
Do I need planning permission to convert a house into flats?
Yes, always. Converting a single dwelling into two or more self-contained flats is a change from one home to several, and that subdivision is treated as development requiring a full planning application — there is no permitted development route that allows it, regardless of the property's size or whether the exterior changes at all. The application has to demonstrate that each flat meets space, layout, amenity and parking standards in its own right, not just that the building as a whole is being used sensibly.
Boroughs also weigh the loss of a family-sized house against their local housing policy, since converting a larger house into several flats reduces the stock of homes suited to families even as it adds smaller units. We take that policy context into account when advising on layout and unit numbers, rather than simply maximising the number of flats the floor area could technically support.
What sound insulation is required between flats?
Part E of the building regulations sets minimum sound insulation standards for the walls and floors separating flats, covering both airborne and impact sound. Where an existing house is subdivided, the drawings specify how the party floors and walls between units will be upgraded — additional layers, resilient bars, or a floating floor — and pre-completion sound testing is normally required before the flats can be signed off. Getting this detail right on the drawings from the outset matters, because retrofitting sound insulation after a failed test usually means taking up a finished floor or ceiling that has already been decorated.
How do you design fire escape and compartmentation for flat conversions?
Each flat needs its own independent means of escape to a place of safety, and the building has to be compartmented so that fire in one flat does not spread into another or into the shared circulation space. On a typical converted house this means fire-rated floors, walls and doors between units, and either a protected common stairway shared by the flats or separate final exits for each one, depending on the layout.
Where flats sit above ground floor level, escape routes and fire doors are designed together with the sound insulation upgrade, since the same floor and wall build-ups often need to satisfy both requirements at once.
| Conversion | Typical scope | Route | Fee from |
|---|---|---|---|
| House to two self-contained flats | Vertical split, separate or shared entrance | Full planning plus building regulations | £1,600 |
| House to three or more flats | Multiple units, fire strategy required | Full planning plus building regs plus structural | £2,400 |
| Flat conversion with a side or rear extension | Additional floor area added to create compliant units | Full planning plus structural calculations | £2,800 |
Flat Conversion Drawings across Greenwich
Flat Conversion Drawings in Greenwich — FAQs
Do I need planning permission to convert a house into flats?+
How much do flat conversion drawings cost in London?+
What sound insulation is required between flats?+
Does each flat need a separate fire escape?+
What is the minimum size for a flat in London?+
Do I need planning permission for an extension in Greenwich?+
How does the Maritime Greenwich World Heritage Site affect my project?+
Can I extend a home in Blackheath or Westcombe Park?+
How long does the Royal Borough of Greenwich take to decide?+
How much do planning drawings cost in Greenwich?+
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