Small boundaries, more council evidence
Two small conservation areas in the London Borough of Merton make up the study area: Lambton Road at about 8.4 hectares and Durham Road at about 3.9. Merton's neighbourhood character study records that roads including Durham, Lambton and Pepys were laid out on large plots after the Cottenham Park estate was split up, although development only started, slowly, once trains began stopping at the station in 1871.
With one list entry and practically no mapped flood zone, the national datasets say little about these streets, so Merton's own documents carry more of the weight: the character study, the conservation-area list, a flood alleviation study for the Raynes Park catchment and the borough's Article 4 page. Surrounding districts are covered in the south-west London guide.
Council and national records for SW20
Every statement below links to the public record it comes from; sources were re-checked on .
Two boundaries, one date
The Lambton Road record, reference 2816, and the Durham Road record, reference 2812, both show a record start date of 29 November 1990 on planning.data.gov.uk.
Merton's list of conservation areas publishes a map, character assessment, boundary assessment and design guide for Lambton Road, but for Durham Road a map, character assessment and boundary assessment without a design guide.
Article 4 documents appear on that list for other areas, such as John Innes Merton Park and Wilton Crescent, but not for Lambton Road or Durham Road, and the national Article 4 dataset has no polygon over either boundary.
Stock-brick terraces round Lambton Road
Much of the Lambton Road character area lies inside the conservation area, according to the Raynes Park neighbourhood character study, with tight-knit terraces on Trewince, Tolverne, Rosevine, Kenwyn and Pendarves Roads on level ground between the moderate slopes of Lambton and Pepys Roads.
The study describes yellow London stock brick with red brick decorative courses, canted double bays with sash windows and raised party wall parapets, details that tie each roof and front wall to the neighbours on either side.
Among the issues it records are infilled recessed porches, added porches, isolated instances of painted-over brickwork and multiple rooflights on the front roof slope, and its guidance asks owners to avoid total infilling of entrance canopies, glazed porches and dormer roof extensions.
A loft room or enclosed porch on these streets is therefore matched to a permission, and a painted front is looked at for the condition of the stock brick it covers, with the character study as the reference for what was there originally.
Maisonettes on Panmuir Road and Durham Road
The character study describes a pocket of Victorian and Edwardian terraced maisonettes on Panmuir Road and Durham Road, built as short terraces that mostly hold eight maisonettes, each terrace with two entrances and a richly detailed central recessed porch.
At the corner of Cambridge Road and Durham Road it notes two buildings with octagonal corner turrets under steeply pitched slate pyramid roofs, and it records brick ground floors with pebbledash to the first floor, terracotta coping tiles on the party walls and original sliding sash windows, as the study describes them.
A maisonette in such a terrace shares its porch, roof and party walls, so the study's description is read with the lease plan to see who answers for a turret roof, a slipped slate or a loose coping tile.
Head on clay and summer flooding
Four of five sample points carry Head, a mixed deposit of clay, silt, sand and gravel, over London Clay Formation on the 1:50,000 BGS map, and the fifth shows the clay with no superficial cover recorded.
Clay this close to the surface swells and shrinks as its moisture changes, so a crack in one of these terraces is read against nearby trees, drain runs and the age of any rear addition before the mapped ground is blamed.
The Environment Agency's planning flood map records 0.0% of the study area in Flood Zone 2 and none in Flood Zone 3, yet Merton's Raynes Park Flood Alleviation Study page says the catchment has flooded almost every summer over the past 15 years.
That page traces the flooding to the surface water and foul sewer networks as well as the Beverley Brook and Pyl Brook, and lists upgraded town-centre highway drainage, a raingarden at Coombe Lane and Pepys Road, and new and upgraded pumps under the railway bridge on Approach Road.
Its study, run with Thames Water, the Environment Agency and Network Rail, began in spring 2024 and was scheduled to conclude in spring 2026, but the latest project update on the study page dates from spring 2025. That page and the surface-water layer of the long-term flood risk service are therefore both checked for the address.
Listing, the station and local plan policy
Inside the 12.3 hectares the national list layer finds a single Grade II entry, so for nearly every house here the controls that matter come from conservation-area status rather than listing.
The NaPTAN dataset places Raynes Park rail station 140 metres outside the boundary, and Merton's local plan page for the area records policy N6 of the Local Plan adopted in November 2024, which aims to improve the environment and movement around the local centre.
Borough-wide, Merton's Article 4 page says converting a home into a house in multiple occupation of any size now needs planning permission anywhere in Merton, the later of two immediate directions having started in March 2026.
Housing in one statistical area
The only LSOA with a quarter or more of its area inside the boundaries is E01003443, which the VOA's 2025 property stock release credits with about 680 dwellings, rounded to the nearest 10.
Its two earliest build periods, before 1900 and 1900-1918, hold 35.3% each in the VOA age table, with 13.2% from 1919-1939 and only 4.4% from 2000 onwards.
Terraced houses are 48.5% of the VOA type counts, flats and detached houses 17.6% each and semi-detached houses 16.2%, while band F is the commonest at 35.3% and bands F to H reach 67.6%.
Local guides and firm-wide services
Each local guide covers one kind of instruction for homes in and around these two conservation areas, and each practice page explains that service for any address.
Other guides nearby
The south-west London hub covers the wider district. Wimbledon, Merton Park, New Malden and Morden have neighbouring guides, while Southfields and Petersham and Ham are covered elsewhere in south-west London.
Questions about the Lambton Road and Durham Road areas
Does the flood map show risk in these conservation areas?
Almost none: the planning flood map gives 0.0% in Flood Zone 2 and nothing in Flood Zone 3. Merton's flood study page still reports flooding in the wider catchment almost every summer for 15 years, from sewers as well as the brooks, so surface water and drainage are checked at the address.
Is there a design guide for Lambton Road?
Yes. Merton's conservation area list publishes one alongside a character assessment, boundary assessment and map, while Durham Road has a character assessment and boundary assessment but no design guide listed.
Would a dormer suit a Lambton Road terrace?
The character study's guidance asks owners to avoid dormer roof extensions and to keep rooflights off the front slope. Whether a particular scheme can go ahead is a planning question for Merton, raised before drawings are commissioned.
Can a house here become a shared house without permission?
Not as a house in multiple occupation, unless the property type is on Merton's HMO exemption list. Merton's Article 4 page says converting a home into a house in multiple occupation of any size needs planning permission anywhere in the borough, and licensing is a separate requirement.
How old is the housing in the statistical area?
Mostly old. Before 1900 and 1900-1918 each account for 35.3% of about 680 dwellings, and terraced houses are the largest type at 48.5%. The figures cover one LSOA rather than the two conservation areas exactly.
What helps before buying a maisonette on Durham Road?
The lease and its plan, how repairs to the shared porch, roof and party walls are divided, repair records for the building, and planning papers for alterations such as rooflights or replacement windows.
How we work on an instruction
Hampstead Chartered Surveyors is a RICS-regulated firm (RICS Regulated Firm No. 923064) working from its registered Hampstead NW3 office. The firm does not claim premises, staff or completed instructions in an individual locality, and it does not treat a neighbourhood name as evidence about a particular building.
An instruction starts with the full address, the decision the client faces and the documents already available, such as leases, drawings, notices or earlier reports. The scope, fee and inspection date are confirmed in writing only after that review, and access to roofs, lofts, basements or common parts is agreed before the visit.
Reports include RICS Level 2 and Level 3 home surveys, building and defect investigations, party wall appointments, reinstatement cost assessments, contract administration and schedules of condition. Each report records what was inspected, what could not be seen and what further investigation the evidence supports.
Public datasets such as the conservation-area register, the National Heritage List for England, British Geological Survey mapping, the Environment Agency flood map and Valuation Office Agency housing statistics describe areas rather than individual properties. They frame questions before an inspection; they never replace it.
Reviewed by Savas Bulduk BSc (Hons) MRICS, Director & Chartered Building Surveyor at Hampstead Chartered Surveyors & Building Consultancy. Last reviewed: . Our people · RICS firm record