Living room with tall steel windows and herringbone parquet.

Planning consultants in Chelsea.

Chelsea · SW3 · Chelsea basement and extensionCompleted work, photograph

Planning for Chelsea terraces, where most applications concern the back and the roof. Drawn, priced and built by one team.

Talk to NickHe calls you back within the hour, in working hours

Or call 020 7731 6841We use your details only to reach you. Privacy note

A Chelsea application, read from the back.

CD13
The test for rear additions
CD12
The test for a roof storey
SW3 · SW10
Wholly inside the Royal Borough

NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle planning applications and appeals in Chelsea SW3, under one contract. Fees are priced per project by our own quantity surveyor, from the actual scope. Call 020 7731 6841, and a budget estimate typically follows within seven days.

Chelsea is Victorian and Georgian terraces, often four storeys and sometimes five. Garden squares sit between them. Most of Chelsea is conservation area, so street fronts rarely change.

The real questions come at the back and on top. Two policies in the 2024 Local Plan decide them. CD13 governs rear additions and CD12 governs roofs.

CD13 holds an addition to the neighbours’ rear line, below the eaves. It also guards the even rhythm along a terrace. So we photograph and measure every back along the row.

CD12 resists an extra storey where a terrace roofline is complete. Where neighbours already built up, an infill can be argued. Precedent along the group is evidence, and we gather it.

An officer then weighs the drawings, elevations and sections against both tests. If the answer is no, we redesign or take it to appeal. Our site team builds whatever is consented.

What Kensington and Chelsea weighs in Chelsea.

Council
The Royal Borough of Kensington and Chelsea decides every Chelsea application.
Rear additions
Policy CD13. Keep the terrace’s even rhythm, the neighbours’ rear line and the eaves.
Going up
Policy CD12. An intact group roofline takes no extra storey.
Infill
A terrace already broken by varied roof extensions may accept an infill.
Applications
Conservation area schemes go in as full applications. Outline is refused.

Source: Kensington and Chelsea’s Local Plan 2024, Policies HO1 and CD4 to CD13. Read on 7 October 2026. Policies change, so we read them again for your address.

What planning costs in Chelsea.

Each application is priced from its own scope.

Our quantity surveyor sets the fee out in writing before you commit.

Open the calculatorThe 2026 cost guide

How far back can a Chelsea rear extension go?

Policy CD13 sets a line, not a fixed number of metres.

It should stop at the general rear line of neighbouring additions.

Height stays under the main eaves too.

Can I add a mansard to my Chelsea terrace?

Only where the roofline is already broken by extensions.

On a complete, unaltered roofline, CD12 resists an extra storey.

We survey the whole group before advising.

Is permitted development any help on a Chelsea house?

Less than people hope, because conservation areas cover most streets.

There, roof additions get no permitted development at all.

The larger rear route by prior approval is closed too.

What happens if my Chelsea scheme is refused?

We read the reasons against CD12 and CD13, line by line.

Often a revised design answers them faster than an appeal.

Where the scheme is sound, we prepare written grounds for the Planning Inspectorate.

Tell us about your home in Chelsea.

Your name and one way to reply are enough. It goes straight to the studio.

A phone number or an email is enough. We only need one.

Where did you find us? Optional
Optional, it helps us prepare
What is the work?