— Streatham Hill · Streatham Common · Telford Park · SW16

Loft conversions in Streatham.

Two estates in SW16 carry Article 4 directions that restrict what you can do to a roof. On one of them, older directions have lapsed — so half the advice you’ll read online is out of date.

Streatham is mostly late Victorian and Edwardian, on generous plots with good roof volume — genuinely good loft conversion stock. Most of it keeps full permitted development rights. But Lambeth has designated a lot of SW16, and two estates carry directions that go further. This page names both, with dates.

— The two estates

Streatham Lodge and Leigham Court Estate: the two Article 4 directions in SW16.

Most Streatham conservation areas rely on designation alone. Two go further and carry their own Article 4 directions — which means permitted development rights that survive elsewhere in the borough have been formally removed there.

Streatham Lodge (CA62) — and the directions that lapsed

The Streatham Lodge conservation area was first designated on 8 June 2009. Its heart is the Streatham Lodge Estate — late 19th and early 20th century houses in a mature suburban setting.

An Article 4 direction was served on 23 July 2010, confirmed on 18 October 2010, with formal notification issued on 2 and 3 December 2010.

Two details matter here, and both are routinely missed.

First, the 2010 direction covers only part of the conservation area, not all of it. Being inside CA62 does not automatically mean the direction applies to your house.

Second, and more useful, the council states plainly:

If you have been told your house on the Streatham Lodge Estate is bound by an Article 4 direction from before 2010, that advice is out of date. Only the 2010 direction is live. This matters commercially: people abandon perfectly viable schemes on the strength of a restriction that no longer exists.

Leigham Court Estate (CA31) — a model estate protected since 1981

Designated on 18 February 1981, with an Article 4 direction documented in a report from 1995 and a notice from 1996. Leigham Court Estate was built by the Artizans, Labourers and General Dwellings Company between 1889 and 1928, and the council describes it as an early example of a model housing estate — long terraces of good-quality, purpose-built flats and houses, laid out on a grid in repeating styles.

That phrase — repeating styles — is the whole point, and it explains why the council protects the estate as hard as it does. On a grid of hundreds of near-identical houses, the uniformity is the heritage asset. A dormer that would disappear on a mixed Victorian street reads as a broken tooth here.

Leigham Court Estate also has something most conservation areas do not: its own Supplementary Planning Guidance, adopted in 2001, published alongside the boundary map and the 1995 Article 4 report. If your house is on the estate, that SPG is the document your application will be measured against. Read it before your architect draws anything — it is free, and it will save you a refusal.

— The wider picture

Streatham’s other conservation areas.

Lambeth has 62 conservation areas covering approximately 30% of the borough, and Streatham carries a substantial share. Beyond the two estates above, these catch houses across SW16:

How to check your own address in two minutes

Lambeth publishes the answer free. Search your address on the council’s planning application database, open the result and click the Constraints tab — conservation area status, any Article 4 direction and any planning condition affecting the site are all listed there. Lambeth also publishes an interactive map of every conservation area, and a downloadable profile page for each one with designation reports and boundary maps.

Everything is reachable from Lambeth’s conservation area profiles page. The planning team is on 020 7926 1180.

Checked against Lambeth Council’s published conservation area profiles for Streatham Lodge (CA62) and Leigham Court Estate (CA31) in July 2026. Directions are made, confirmed and allowed to lapse. Confirm your own address with Lambeth Council or the Planning Portal before committing to a design.

— Outside the designated areas

Most of Streatham keeps full permitted development rights.

It is worth saying clearly, because the list above can make SW16 look more restricted than it is. Outside the designated areas, a Streatham house normally keeps full permitted development rights: up to 40 cubic metres of added roof volume on a terrace, or 50 on a semi-detached or detached house, provided nothing projects forward of the roof plane facing a highway, nothing rises above the existing ridge, and materials are similar in appearance to the existing house. Side-facing windows must be obscure-glazed and non-opening below 1.7 metres.

Streatham’s late Victorian and Edwardian stock is well suited to this. Deep roofs, decent ridge heights, and plenty of houses with a rear addition to build an L-shaped dormer over. Even where permission is not needed, apply for a Lawful Development Certificate — it takes around eight weeks, costs a fraction of a full application, and stops a conveyancing solicitor holding up your sale in five years’ time.

— What we build

Types of loft conversion we build in Streatham.

L-shaped dormer

For the Victorian and Edwardian terraces with a rear addition — two dormers joined over the main roof and the back addition, producing a double bedroom plus a separate bathroom. Invisible from the street, and frequently permitted development outside the conservation areas.

Hip-to-gable with rear dormer

For the semi-detached stock around Streatham Common and the Leigham Court Road areas. Squaring off the hipped end recovers the volume a hip roof wastes; combined with a rear dormer it usually produces two rooms rather than one.

Set-back rear dormer

The conservation area answer. Sits below the ridge and in from the party walls so it reads as subordinate to the original roof. On Leigham Court Estate, where the rhythm of the terraces is the thing being protected, this restraint is not a compromise — it is what gets approved.

Conservation rooflight conversion

No change to the roof shape at all — flush conservation-pattern rooflights set into the existing slope. Where an Article 4 direction is live and the roofscape is tightly controlled, this is often the only route to a usable room, and Streatham’s generous roof volumes mean it delivers more than you would expect.

— Building Regulations

Building Regulations apply either way.

Permitted development means you may not need planning permission. It never means you can skip Building Control. Structure under Part A — existing ceiling joists are never adequate as floor joists, so new joists and usually steel beams. Fire safety under Part B — a loft makes a third storey, which triggers a protected escape route, fire doors off the stairwell and interlinked mains-powered alarms on every level. Stairs under Part K, insulation under Part L, ventilation under Part F.

Where the house is semi-detached or terraced, the Party Wall etc. Act 1996 applies before anyone cuts into or builds off a shared wall. Two months’ notice, running in parallel with the planning process. We manage the notices; the surveyor’s fee sits outside our quote.

— Costs

Loft conversion costs in Streatham.

Honest 2026 ranges. Streatham sits below Clapham and Wimbledon, mainly because access is easier — more houses with side returns and somewhere to put a skip — and because most of the stock is outside the conservation areas where materials have to be matched.

Why these look lower than the London averages you’ll read elsewhere

Published London figures often quote £3,000 to £4,500 per square metre. Ours work out lower, for three reasons and no catch. Those averages are usually Inner London rates, and SW16 is not Chelsea. They are frequently quoted inclusive of VAT and professional fees, where ours exclude both and say so. And we run a maximum of three projects at a time with our own trades, so there is no management margin stacked on another contractor’s margin.

→ See our full pricing guide for South London renovations

— Why LMDEC

Why Streatham homeowners choose us.

We check which direction is actually live before we quote. Two decades of hands-on experience on South London period homes, and enough Lambeth conservation area work to know that a lapsed direction is not a restriction. The people who quote your job are the people who build it.

A fixed price in writing, and realistic dates. Every quote itemised before work starts. If the strip-out uncovers something genuinely hidden — and Edwardian Streatham hides plenty — you see the cost and the options before anyone continues. A maximum of three projects at a time across the whole company.

£2 million Public Liability insurance, two-year workmanship warranty, six-month return visit included. Wet rooms and tanked floors carry a separate ten-year waterproofing guarantee. All gas work by individually qualified Gas Safe registered engineers; all electrical work by individually qualified NICEIC certified electricians. Building Regulations completion certificate and your guarantee in writing on handover.

Every project includes the Prestige Client Portal at no extra cost. A live schedule, dated site photographs, every drawing and consent in one secure place, and one-click approval of any variation with the cost shown before you decide.

— Common questions

Frequently asked.

Part of our loft conversions across South London — including neighbouring Clapham, Dulwich and Croydon. Looking at an extension or full refurbishment instead? We do those too.