Rear Extension Drawings in Merton
Fixed-fee, MCIAT-chartered rear extension drawings for Merton homeowners — London Borough of Merton validation and local constraints handled from the start.
Merton runs from the sought-after Victorian villas and terraces of Wimbledon Village and South Wimbledon and the planned John Innes estate at Merton Park down through the interwar semis of Raynes Park and Morden to the historic Cricket Green at Mitcham and the streets of Colliers Wood. Loft conversions and rear extensions are the borough's signature projects, with strong conservation control around Wimbledon and Merton Park tightening design where it applies.
The character shifts across the borough. Conservation areas at Wimbledon Village, Wimbledon Common, the John Innes estate at Merton Park, Mitcham Cricket Green, Colliers Wood and Wimbledon West Side control materials, rooflines and front elevations, and the John Innes estate's distinctive Arts-and-Crafts character is protected especially closely, with permitted development often restricted there. Article 4 directions remove permitted development for HMO conversions in designated wards, and toward Raynes Park and Morden the council expects extensions to respect the consistent interwar building lines. Those interwar semis, however, frequently retain permitted development rights for rear extensions and lofts.
We prepare Merton planning drawings that respect the character of the specific area — the Arts-and-Crafts detailing of Merton Park, the villa streets of Wimbledon, and the suburban lines of Raynes Park and Morden — checking permitted development eligibility and any Article 4 or conservation constraint first. It is the same council-accepted drawing set an architect would produce, usually at around 30% less, with a fixed fee agreed up front, a roughly seven-day drawing turnaround and free redraws until the London Borough of Merton 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 outset.
Planning in Merton: what to know before you apply
Merton applies Article 4 directions to HMO conversions in designated wards and controls design within conservation areas such as Wimbledon Village, Wimbledon Common and the John Innes estate at Merton Park. For the borough's interwar semis around Raynes Park and Morden, rear extensions and lofts frequently qualify as permitted development — we confirm before drawing.
Typical Merton housing stock
Victorian and Edwardian villas and terraces around Wimbledon and South Wimbledon, the planned Arts-and-Crafts John Innes estate at Merton Park, and interwar semi-detached suburbia through Raynes Park, Morden and Mitcham.
Areas we regularly draw for in Merton
Wimbledon · Mitcham · Morden · Raynes Park · Colliers Wood · Merton Park · South Wimbledon · Wimbledon Village
Rear Extension Drawings for Merton homes: the package and the process
Every rear extension drawings we prepare for a Merton property is drawn to London Borough of Merton’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 single-storey rear extension is the most common way London homeowners add space, usually taking the form of an open-plan kitchen-diner that opens onto the garden through bi-fold or sliding doors, with rooflights or a roof lantern bringing daylight deep into the plan. Because depth and height are tightly controlled by permitted development rules and by the 45-degree rule that protects neighbouring windows, the design work sits as much in checking what the council will allow as in drawing what you want.
DrawingsDirect draws rear extensions for permitted development, the larger home extension prior-approval scheme and full householder planning, with structural calculations for the opening and roof produced in-house by our MCIAT-chartered team. If your project also involves widening the kitchen sideways or adding a second storey, see our Side Return, Wraparound and Double Storey Extension pages — many London rear extensions grow into one of those during design.
Do I need planning permission for a rear extension in London?
Many single-storey rear extensions qualify as permitted development, meaning no planning application is needed, provided depth, height and materials stay within set limits. That changes if your property sits in a conservation area or is subject to an Article 4 direction, both of which can remove permitted development rights across a street or borough — in that case a full householder planning application is required regardless of size.
Even where an extension qualifies, most homeowners obtain a Lawful Development Certificate to confirm that status in writing before building — useful for mortgage lenders, buyers and Building Control. We check your property against your borough's constraints before recommending a route.
How deep can a single-storey rear extension go?
Depth is the main constraint on a rear extension, and it depends on your house type and whether you use standard permitted development or the larger home extension scheme.
Permitted development
Standard permitted development allows a single-storey rear extension up to 3 metres deep for terraced and semi-detached houses, or 4 metres for detached houses, generally with eaves height limited to match or stay close to the existing house.
Larger home extension scheme
The prior-approval scheme extends this to 6 metres for terraced and semi-detached houses and 8 metres for detached houses. Your council writes to affected neighbours; if none object within the notification period, approval follows without a full planning application. If an objection is raised, the council assesses the impact on neighbouring light and outlook itself, rather than automatically refusing, so a well-considered design still has a good chance of approval.
| Route | When it applies | Typical fee |
|---|---|---|
| Permitted development (Lawful Development Certificate) | Depth within 3m (terraced/semi) or 4m (detached), height and materials within PD limits | PD/LDC pack ~£950–£1,450 |
| Larger home extension (prior approval) | Depth up to 6m (terraced/semi) or 8m (detached), with neighbour notification | from £1,100 |
| Full householder planning permission | Extension exceeds PD/larger-home limits, or the property is in a conservation area with an Article 4 direction | Full Planning pack ~£1,600–£2,400 |
| Planning + Building Regulations (structural) | Combined planning and construction-ready pack with structural calculations for the opening and roof | Planning + Building Regs pack ~£2,200–£3,850 |
Rear Extension Drawings across Merton
Rear Extension Drawings in Merton — FAQs
How much does a rear extension cost to design in London?+
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How long does it take to get rear extension drawings?+
What is the 45-degree rule?+
Will I need a Party Wall Agreement for a rear extension?+
Do I need planning permission for an extension in Merton?+
What is special about building at the John Innes estate in Merton Park?+
What do Merton's HMO Article 4 directions affect?+
How long does Merton Council take to decide?+
How much do planning drawings cost in Merton?+
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