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Free 2026 London Planning ReportBasement Conversion Drawings in Greenwich

Aerial view of London rooftops and gardens across a borough like Greenwich, from historic terraces to suburban homes
Greenwich · London

Basement Conversion Drawings in Greenwich

Fixed-fee, MCIAT-chartered basement conversion drawings for Greenwich homeowners — Royal Borough of Greenwich validation and local constraints handled from the start.

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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.

Aerial view of London rooftops and gardens across a borough like Greenwich, from historic terraces to suburban homes
Isometric illustration of a Greenwich home extension design
Proposed floor plan
Greenwich

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

Basement Conversion Drawings for Greenwich homes: the package and the process

Every basement conversion drawings we prepare for a Greenwich property is drawn to Royal Borough of Greenwich’s validation standards and tuned to the local constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.

A basement conversion is one of the few ways to add genuine living space to a London home without touching the footprint above ground, but the drawings have to earn their keep in two very different disciplines at once. Converting an existing cellar into a habitable room is largely a building-regulations exercise, while digging out a new basement or lowering an existing floor is a structural undertaking that usually brings planning permission, underpinning design and neighbour consultation into the project as well.

DrawingsDirect prepares both types of basement drawing set for London homes — fit-out packages for existing cellars and full structural packages for new-dig or lowered basements — with waterproofing, means of escape, ventilation and Party Wall coordination built in from the first survey. As a chartered architectural technologist practice, we produce the structural design in-house rather than outsourcing it, so the drawings and the calculations arrive together, checked against each other, at a fixed fee.

Do I need planning permission for a basement conversion in London?

An internal conversion of an existing cellar — new floor, insulation, a habitable layout — often does not need planning permission, because the works sit entirely within the existing structure and do not change its external appearance. Digging out a new basement, lowering an existing floor to gain headroom, or enlarging the footprint under a garden usually does, particularly where excavation extends beyond the existing building line. Any external alteration needed to serve the basement — a front light well, a sunken external staircase, or altering the pavement or front garden — is also likely to need planning permission in its own right, even when the basement works themselves would not. In a conservation area, a front light well tends to draw closer scrutiny than the same feature elsewhere, since it changes the street-facing elevation and the pavement it sits within — one more reason we assess the whole scheme, not just the room below ground, before recommending a route.

Cellar conversion or new dig-out — which route fits your property?

The two starting points lead to very different drawing sets. A cellar conversion works with a void that already exists: the drawings focus on damp-proofing, insulation, headroom, natural or borrowed light, means of escape and a compliant layout, coordinated with building regulations rather than planning.

A new dig-out or floor-lowering project starts from a structural decision — how the existing foundations will be underpinned to allow excavation beneath them — and the drawings and structural calculations are produced together from the outset, since the sequence of underpinning, temporary works and waterproofing has to be engineered before a builder can safely start.

Basement conversion drawing packages in London
RouteTypical scopePlanning positionFee from
Existing cellar conversionFit-out of an existing void, no excavationUsually building regulations only£2,400
Floor lowering / partial dig-outIncreases headroom within the existing footprintOften needs planning permission£3,200
New-build basement or light well extensionNew basement area beyond the existing footprintFull planning plus Party Wall Act£3,850
FAQ

Basement Conversion Drawings in Greenwich — FAQs

How much do basement conversion drawings cost in London?+
Packages start from around £2,400 for converting an existing cellar and rise to around £3,850 for a full planning and structural package covering a new dig-out or floor-lowering project. We agree the fee upfront once we know which route your property needs.
Does a basement conversion need planning permission?+
Converting an existing cellar often does not, since the works are internal. Digging out a new basement, lowering a floor, or adding external features such as a front light well usually does. We check your specific property before recommending a route.
Will I need a party wall agreement for a basement conversion?+
Almost always, if excavation takes place near or below a shared boundary. The Party Wall etc. Act 1996 requires notice to adjoining owners before underpinning or excavation begins, and we identify likely notifiable neighbours from the drawings.
Are structural calculations included in a basement conversion package?+
Yes — underpinning sequences, steel beams and retaining structures are calculated in-house as part of the same fixed fee, so the drawings and the engineering are never produced separately.
Do I need an architect for a basement conversion?+
No. As an MCIAT-chartered architectural technologist practice we produce the same council-accepted drawings as an architect, typically around 30% cheaper, with structural design coordinated in-house rather than outsourced.
Do I need planning permission for an extension in Greenwich?+
It depends on the area. The interwar and post-war suburbs toward Eltham and Kidbrooke often retain permitted development rights for rear extensions and lofts, while the historic core around West Greenwich and Blackheath sits within conservation areas where those rights are removed. We check your address against the designations first and can confirm permitted development with a Lawful Development Certificate.
How does the Maritime Greenwich World Heritage Site affect my project?+
Proposals within the World Heritage Site or its buffer zone are assessed against the setting of Maritime Greenwich, where the council protects townscape and long views toward the Royal Observatory. It doesn't rule out an extension, but roof-level and prominent works near the site need careful, context-led design. We confirm whether the setting applies to your address before drawing.
Can I extend a home in Blackheath or Westcombe Park?+
Yes, but these conservation areas carry strong design control over materials, rooflines and front elevations, and sloping sites around Blackheath and the Greenwich hills shape what works. We design context-led drawings that respond to the area's Georgian and Edwardian character and the topography, which is what carries applications to consent here.
How long does the Royal Borough of Greenwich take to decide?+
Greenwich determines most householder applications within the statutory eight-week period once validated; World Heritage Site, conservation and protected-view cases can involve additional consultation. We prepare submissions to the council's validation checklist to avoid the drawing queries that cause most delays.
How much do planning drawings cost in Greenwich?+
We agree a fixed fee before starting, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Greenwich approves. A suburban Eltham extension and a West Greenwich heritage application differ in the evidence required, so we quote once we understand your address and project rather than by the hour.
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