Double Storey Extension Drawings in Morden SM4
Fixed-fee, MCIAT-chartered double storey extension drawings for Morden (SM4) homeowners — London Borough of Merton validation and local constraints handled from the start.
Morden (SM4) sits at the southern edge of the London Borough of Merton, taking in the John Innes estate streets of southern Merton Park and the older village core around St Lawrence Church.
SM4 is shaped by two conservation areas, John Innes Merton Park and Upper Morden, the former carrying some of London's most restrictive Article 4 Directions on permitted development.
Planning in Morden (SM4): what to know before you apply
Houses on the John Innes estate streets within SM4 are covered by Article 4 Directions that withdraw permitted-development rights, so changes to windows, doors, front walls and roofs there need a full planning application; the borough-wide HMO Article 4 applies across the rest of Morden.
Typical Morden housing stock
John Innes estate cottages and villas of the 1870s onward with hedged front gardens and distinctive detailing, alongside the older core around St Lawrence Church and Church Farm Cottage near London Road, and inter-war suburban housing spreading toward Morden town centre.
Streets we regularly draw for in Morden
Dorset Road · Kingston Road · London Road · Central Road · Mostyn Road
Double Storey Extension Drawings for Morden (SM4) homes: the package and the process
Every double storey extension drawings we prepare for an Morden property is drawn to London Borough of Merton’s validation standards and tuned to the SM4 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.
A double storey extension builds a second floor above a single-storey side or rear addition, typically adding a bedroom and bathroom upstairs over a widened kitchen or reception room below. Because the foundations and roof of a single-storey extension already carry most of the fixed cost of building, adding a floor on top is often the most cost-effective way to gain two rooms rather than two separate projects. The trade-off is scrutiny: a two-storey addition sits closer to eye level with neighbouring windows and gardens, so councils examine massing, roofline and boundary distance more closely than they would a single-storey extension.
DrawingsDirect draws double storey side and rear extensions for full planning and building regulations, with structural calculations for the additional floor load and foundations produced in-house by our MCIAT-chartered team, on a fixed fee. If a single storey is enough, see our Rear Extension and Side Return Extension pages, or combine both with a Wraparound if you are extending sideways as well as up.
Do I need planning permission for a double storey extension in London?
Almost always. Permitted development rights for two-storey extensions are far more restrictive than for single-storey work, particularly on how close the new structure can come to a boundary and how closely its roof pitch and eaves height must match the existing house, so most double storey projects are drawn and submitted as full householder planning applications rather than relying on permitted development.
Where the property sits in a conservation area or is subject to an Article 4 direction, any remaining permitted development allowance for a second storey is typically removed entirely, reinforcing the need for a full application. We check your property's status and your borough's design guidance before drawing.
How do councils control the impact of a double storey extension on neighbours?
Because a second storey introduces new windows and massing at first-floor level, London boroughs apply design guidance aimed specifically at protecting neighbouring light, privacy and outlook.
- The 45-degree rule, tested at neighbouring windows, to check the extension does not block an unreasonable amount of daylight
- A common design expectation that a two-storey side extension is set in roughly 1 metre from the shared boundary, rather than built hard against it
- A first floor commonly set back from the ground floor front elevation, so the upper storey reads as subordinate to the main house from the street
- Obscure or high-level glazing on flank walls facing directly into a neighbour's garden or windows, to limit overlooking
| Option | What it adds | Typical fee |
|---|---|---|
| Single-storey rear extension | A ground-floor kitchen-diner only, may qualify for permitted development | see Rear Extension Drawings, from £1,100 |
| Double storey side or rear extension | Two rooms across two floors, usually needs full planning | Full Planning pack ~£1,600–£2,400 |
| Double storey + Building Regulations (structural) | Combined pack including structural calculations for two-floor loads and foundations | Planning + Building Regs pack ~£2,200–£3,850 |
| Wraparound (rear + side return) | Combines two single-storey extensions into one L-shaped ground floor | see Wraparound Extension Drawings, from £2,200 |
Double Storey Extension Drawings in Morden SM4 — FAQs
How much does a double storey extension cost to design in London?+
Do I need planning permission to add a second storey?+
Will a double storey extension overlook my neighbour's garden?+
Do I need an architect for a double storey extension?+
How long does it take to get double storey extension drawings?+
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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Tell us your Morden (SM4) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.