Rear extension drawings in Merton

Gardens and the space you keep

Domestic gardens cover about 27.2 per cent of the borough's land in the Greater London land-use survey, which is why a rear extension is a natural project here. The garden is the resource you are spending, so we show the remaining length and the usable area on the block plan.

National rules add a ceiling of their own: Buildings (other than the original house) may not cover more than 50% of the curtilage. On a short Merton plot, that limit can bite before the depth limit does, and it counts earlier outbuildings too.

Permitted development, prior approval or planning permission

A single-storey extension inside the national limits can often go ahead without an application, and a Lawful Development Certificate in Merton records that in writing. A deeper one can use prior approval: 6 m (attached) / 8 m (detached), single storey, height max 4 m; not on article 2(3) land or an SSSI.

Prior approval is not a formality here. In the latest national statistics year Merton granted 22 larger home extension prior approvals and refused 80. Neighbours are consulted on that route, so we test the design against the adjoining windows before it is sent.

Two-storey additions, flats and houses without permitted development rights go through a householder application, drawn as in our planning drawings in Merton.

Conservation areas and listed houses

Merton has 28 conservation areas. The deeper prior approval route is not available on that kind of land, and materials and roof form get closer scrutiny. We check your address against the council's map before suggesting a route.

Historic England lists 243 entries in the borough. A listed house needs listed building consent for work affecting its character, whatever the size of the extension.

How Merton handles householder applications

Merton decided 759 householder applications in its latest published year and granted 92.9 per cent of them. Some 85.2 per cent were decided within eight weeks or an agreed extension, so we advise a small buffer in your building programme.

These are borough-wide figures about the past. They describe how often applications succeed, not whether yours will, and we never present them as a forecast.

What you receive and what it costs

Drawings start at £695 with VAT included, fixed before you commit. The set has existing and proposed plans, elevations and sections, a location plan and a block plan. A second chartered technologist checks every sheet, and if the council asks for changes we redraw at no charge until approval.

Your extension must also satisfy the Building Regulations, which set these limiting values for new elements: New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4. Our building regulations drawings in Merton carry that detail through. Residential extensions can claim relief from the levy: Residential extensions and annexes can claim exemption (claim before commencement).

Related drawings and neighbouring boroughs

Thinking of going further? A side return extension in Merton or a wraparound extension fills more of the plot. For the whole borough, start at architectural drawings in Merton or see the national picture on our rear extension drawings page.

Compare nearby rules in Sutton, Wandsworth and Kingston upon Thames.