Side return extension drawings in Hammersmith and Fulham

Conservation areas and the permitted route

The borough has 47 conservation areas and 268 list entries. Where a conservation area applies, side extensions are outside permitted development altogether, so the householder application is the route. The national rule leaves little room: No side extensions under PD on article 2(3) land (conservation areas etc.).

Outside the conservation areas, permitted development may be open if the extension meets the limits. We run the address check first and give you a written answer, which also tells you whether a lawful development certificate is worth having. Our lawful development certificate page has the details.

Policy without a numbered rule

We could not find a published figure for side extensions in the council's documents that we can cite with a page reference, so we do not give one. Officers decide on design, materials and the effect on neighbours. A grant rate this high suggests that a tidy scheme which respects the terrace is usually welcome, but it does not mean a careless one would be.

For that reason the drawings carry a short design note and show the existing building line, the neighbours' additions and the materials. If similar side returns already stand on your street, we photograph them and put the evidence in the application.

One practical habit helps in this borough. Before we draw, we walk the terrace on the planning register and note every side or rear extension approved in recent years, with its date and its description. The list goes into the covering letter as a short table of precedent. It answers a question case officers often ask, which is whether the council has already agreed something like this on the same street.

Prior approval and the rear

Many owners pair a side return with a deeper rear extension. Under prior approval for larger home extensions, the council granted 3 and refused 1 in the period we hold, a small sample but a favourable one.

Once the side and rear are drawn together, the design is a wraparound and we advise on the route as a whole. Our wraparound extension drawings in Hammersmith and Fulham page explains how.

Prices, houses and gardens

24.6 per cent of households live in a house, an average terraced house costs £1,139,759, and gardens cover 17.1 per cent of the land. That is a small stock of high-value houses, and a set detailed with construction notes suits that kind of house.

The side return itself has two parts we always specify: the glazing, which must stay within the energy rules (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), and the beam, coordinated through structural calculations.

Glazing and the beam are the two items that most often change between the first sketch and the final design. We settle both on paper at the start: how much of the roof is glass, how wide the opening on to the garden is, and which wall the steel will sit on, so that the application and the Building Regulations set describe the same building.

Party walls, price and what you receive

A new wall meeting the neighbour's means notices, and our party wall notices page explains the process. Side return drawings start at £745 including VAT, fixed before you commit, with the council's fee of £548 paid separately.

The set includes existing and proposed plans, elevations, a section and location and block plans. A second chartered architectural technologist checks every sheet, and we redraw free until approval if the council asks for changes. See rear extension drawings in Hammersmith and Fulham and architectural drawings in Hammersmith and Fulham.