Do I need architectural drawings to extend my kitchen in London?

Where the shortcut stops: conservation areas and flats

The larger 6 metre depth is not available on article 2(3) land, which the Order says covers conservation areas, along with National Parks and areas of outstanding natural beauty. Large parts of inner London are in a conservation area, so a deep kitchen there goes straight to a householder planning application, with a full drawn set.

Flats and maisonettes have no Class A rights at all, because the rules apply to a dwellinghouse. A ground-floor flat extending its kitchen into the garden needs planning permission, and usually the freeholder's consent too. Side returns and wraparounds have rules of their own; our wraparound planning post explains why the side part changes the answer.

If your home is a flat, whether you can extend a flat explains the full application route and the lease checks.

The open-plan kitchen: why the steel beam needs a drawing

Most kitchen extensions are built to make one open-plan room, which means taking out some or all of the old back wall. That wall carries the floor and walls above, so its replacement is a steel beam, sized by a structural engineer and shown on a drawing with its bearings and padstones. Building control will not sign off a beam that nobody calculated.

We are a chartered architectural technologist (MCIAT) practice. We draw the extension and the beam position, and a named, insured structural engineer prepares the calculations, so the beam on the drawing is the beam in the calculation. If you are also opening an internal wall, such as between kitchen and dining room, what drawings removing a load-bearing wall needs covers that second beam.

Glazing: the 25% rule behind bifolds and rooflights

Approved Document L, the guidance on the energy rules, says the total area of windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension's floor area, plus the area of any windows and doors the extension removes or covers. The current edition, in its section on extensions, sets this out.

A wall of bifolds and a roof lantern can pass that quickly. It is not a ban: the same guidance lets you show compliance another way, by improving other parts of the extension or by a whole-house calculation. Either way it has to be worked out on the drawings before the glass is ordered, not argued about at the final inspection.

Full plans or a building notice for the kitchen

Building control can be approached two ways. A full plans application is checked before you build, and GOV.UK says to expect a decision within 5 weeks, or 2 months with your consent. A building notice lets work start 2 days after it is submitted, but you do not get formal approval of the plans, and GOV.UK says it is only for smaller projects.

For an extension with a steel beam, new drainage and a lot of glass, we usually suggest full plans: you get an approved set before the builder prices it, so surprises surface on paper. What drawings building control needs for an extension lists each sheet, and what drawings builders need to price an extension explains why a priced set saves arguments later.

What we draw, and how this differs from a kitchen design

A kitchen company's layout shows units and appliances. It is not a planning or building control drawing, and no council or inspector will accept it as one. Our set shows the structure around the kitchen: walls, foundations, beam, roof, glazing, drainage runs and the ventilation for the cooker and the room.

Bring the kitchen layout if you have one and we draw around it, so the soil stack, the extractor route and the rooflight land where the units need them. Our kitchen extension drawings page shows a sample set, and the rear extension drawings service page has the route-by-route fees.