Wraparound extension drawings in London

The limits on each arm

The side arm has its own test: Side extension: single storey, max 4 m high, max half the width of the original house. The rear arm has another: 3 m (attached) / 4 m (detached) beyond the original rear wall, single storey.

Both are measured from the original house, as first built or as it stood on the appointed day, so an earlier conservatory or outrigger uses up part of the allowance. Owners are often surprised how little is left, which is why we measure the original footprint ourselves instead of trusting a sales plan.

When the sums fail, a householder application is the normal answer; our planning drawings page explains how that works. If the design fits within the limits and you want proof, a Lawful Development Certificate confirms it.

Conservation areas and wraparounds

Conservation areas bite hardest on this type of extension. The national rule: On article 2(3) land (conservation areas etc.): no side extensions, no cladding, no rear extension of more than one storey under Class A.

A wraparound contains a side arm by definition, so permitted development cannot deliver one on that land. The route is a planning application, where officers read the design against the character of the street.

That is not a closed door. Matching brick, a considered roof form and glazing set back from the street frontage all help a case. Before drawing, we look at the address and the decisions already made on your road.

Glass, rooflights and the energy check

Glazing is where wraparounds most often come unstuck on the building regulations side. The simple route is capped: Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered. A kitchen opening onto two sides of the garden can reach that ceiling without much effort.

Where the design wants more glass, a calculation can justify it. That route sits under SAP calculations, and it is far better settled at drawing stage because it alters the wall and roof build-up and the size of the doors.

The finished specification carries through into our building regulations drawings.

Layout, light and the existing house

The shape of the room matters as much as its size. A wraparound lets the kitchen, dining and seating areas share one open space with glass on two sides, but the corner where the arms meet is where the structure is busiest: a steel frame, a change in roof level and often a drain run below the slab.

We therefore draw the roof early. A flat roof with a lantern, a pitched roof tucked under the first-floor windows and a monopitch against the side wall each change the ceiling height inside and the look from the street. Seeing them in section before you commit avoids a costly change once the steel is ordered.

Daylight to the existing rooms is the other point. Closing in a side passage can darken a window serving the old kitchen or hall, so we show where light is lost and how a rooflight or an internal opening can restore it.

Party wall notices on more than one boundary

A wraparound meets the neighbour at the side and frequently at the rear too, so expect more than one notice. For a new wall on the boundary, the requirement is: Line-of-junction (new wall) notice at least 1 month before work.

Foundations can add another. The excavation rule: Adjacent excavation notice at least 1 month before work: within 3 m and deeper than the neighbour's foundations, or within 6 m and cutting a 45° line from their foundations. Wraparounds often go deeper than a simple rear room because the footprint is bigger and the steel heavier.

We prepare the drawings that go with the notices through party wall notices, and we suggest a word with each neighbour before anything arrives on their doormat.

Wraparound extension drawings in London: price and package

Wraparound extension drawings start at £1,195, VAT included, fixed and published before you commit. A householder application also carries a council fee of £548, which you pay to the council.

The package holds existing and proposed plans, elevations and sections, location and block plans, and submission if you want us to handle it. Because a wraparound is more involved than a single-direction extension, the second chartered technologist reads the two arms against each other.

If the council raises points, we redraw at no extra charge until the application is decided. Drawings are normally ready around a week after the survey.

Comparing options and boroughs

Boroughs differ on how much garden they will let you cover and how they treat infill on terraces. Pick yours through architectural drawings by area to see local conservation area and Article 4 figures.

Unsure a wraparound is the right shape? Set it beside rear extension drawings or side return extension drawings, or browse the whole range under house extension drawings.