After: the finished single-storey rear extension in white render, with wide garden doors and rooflights, on a 1930s semi

Before: the same house on site in week 11, with bricks, a cement mixer and a wheelbarrow on the patio

Compare before and after at Westcombe Park Road: how much of the on-site photo is shown

Project 02Westcombe Park Road, SE3Rear extension · 2024Read the story

Better rooms for the life you actually live.

A small architecture studio in Blackheath. We design side returns, rear extensions, lofts and basements for south-east London homes, and explain every step in plain English.

Book a free consultation All projects

Space added: 24 m²
Time on site: 16 weeks
Planning route: Prior approval decided in 6 weeks
Build cost band: £96k–£118k example, inc VAT

What are you planning?

Pick a type to see houses like yours, with the planning route each one took.

Three houses, before and after.

Every project page shows the house as it was, the house as it is, what it cost (example bands) and exactly how it got through planning. Drag any photo to compare.

After: the new wraparound kitchen and dining room seen through a wide dark-framed opening

Before: the old uPVC conservatory being stripped out, with boarded frames

Compare before and after at Lee Park

Story 01 Lee Park · SE3 · Conservation area

The conservatory that became the kitchen.

A leaking lean-to and a cramped galley, replaced by one long room that wraps the side return and opens to the garden through a single steel-edged frame. The conservation officer asked for darker brick; the room is better for it.

Added: 32 m²
On site: 20 weeks
Route: Householder approved after amendments

Read the Lee Park story

After: the finished loft room with a row of rooflights, a sofa and deep blue joinery

Before: the empty loft with bare boards and timber rafters

Compare before and after at Burnt Ash Hill

Story 02 Burnt Ash Hill · SE12 · Loft

A quiet room at the top of a loud house.

Two people working from home, two children, one spare bed for grandparents. A rear dormer and a row of rooflights made a calm reading room and guest suite without a planning application.

Added: 28 m²
Route: Permitted development LDC granted, 7 weeks

Read the Burnt Ash Hill story

After: the new lower-ground kitchen with dark units and a glazed wall to a planted lightwell

Before: the original cellar with rough stone walls and a single window

Compare before and after at Crooms Hill

Story 03 Crooms Hill · SE10 · Basement

No room to go out, so they went down.

A damp cellar lowered into a full lower-ground kitchen with 2.7 m ceilings and a planted lightwell. Structural engineer and party wall surveyors on board from day one, and weekly updates for 36 weeks.

Added: 46 m²
On site: 36 weeks
Route: Householder + party wall awards

Read the Crooms Hill story

All eight projects, filterable by type

Before you call anyone, two honest tools.

Get a feel for what's allowed and what it might cost. Both are indicative; we firm things up at your free consultation.

The RIBA stages, drawn to scale.

Architects plan work in eight RIBA stages. Here they are grouped into six phases, each drawn as long as it typically takes on a rear extension.

RIBA 0–1Brief & surveyWe listen, measure up and agree what success looks like.2–4 wks
RIBA 2ConceptTwo or three options and a first cost check.3–5 wks
RIBA 3PlanningDrawings, an application or LDC, and talking to neighbours.8–12 wks
RIBA 4Technical & tenderBuilding regs, engineer, specification and builder prices.6–10 wks
RIBA 5On siteWe inspect, value the work and keep decisions moving.10–20 wks
RIBA 6–7HandoverSnagging, certificates and a one-year check-in.Ongoing