About the Isleworth Riverside Conservation Area
The Isleworth Riverside Conservation Area covers about 155 hectares and was designated by London Borough of Hounslow in 1972. Inside the boundary are 57 listed buildings (6 Grade I, 5 Grade II*, 46 Grade II). The most significant is Floras Column, Syon Park, Grade I. Part of the area lies in flood zone 3, so an extension may need a flood risk assessment.
What changes inside the conservation area
Conservation areas are “Article 2(3) land”. You keep most permitted development rights, but these are removed or tightened.
- Rear extensionElsewhere: 3 m · 6 m with PANo 6 m / 8 m prior approval
- Two-storey extensionElsewhere: 3 mNeeds planning permission
- Side extensionElsewhere: Half the widthNeeds planning permission
- Loft conversionElsewhere: 50 m³Needs planning permission
- Garden roomElsewhere: 2.5 m high by boundariesNot beside the house
- PorchElsewhere: 3 m²Same limits
- Solar panelsElsewhere: 0.2 m projectionSame limits
- Air source heat pumpElsewhere: 1 unitNot facing the road
- Fences, walls and gatesElsewhere: 2 m · 1 m by a roadSame limits
- External claddingElsewhere: Matching materialsNeeds planning permission
- Tree workElsewhere: No notice6 weeks’ notice to the council
- Demolition (over 115 m³)Elsewhere: AllowedNeeds planning permission
Limits for a semi-detached house under the GPDO 2015. An Article 4 direction can remove more.
Article 4 directions here
These overlap the conservation area. Householder directions remove more of the rights above; change-of-use ones don’t affect extending a house.
- Dwellinghouses (C3) to small HMOs (C4) - borough-wide Article 4 DirectionChange of use
- Change of use or development that would result in new dwellings (Class MA/ZA)Change of use
Listed buildings in the conservation area
Any work affecting these needs listed building consent, inside or out. Each links to its entry on the National Heritage List.
- Floras Column, Syon ParkGrade I
- Gate Lodge to Syon HouseGrade I
- Syon HouseGrade I
- Syon House ConservatoryGrade I
- Syon Park Boathouse the PavilionGrade I
- Syon Park Entrance Lodges and Gates, London RoadGrade I
- Church of All SaintsGrade II*
- Garvin HouseGrade II*
- Gates to Syon Lodge Syon LodgeGrade II*
- Gumley House Gumley House (convent)Grade II*
- The London Apprentice Public HouseGrade II*
- 11, Lower SquareGrade II
- 2, Church StreetGrade II
- 42-46, Church StreetGrade II
- 48 and 50, Church StreetGrade II
- 49 and 51, Church StreetGrade II
- 58 and 60, Church StreetGrade II
- 59, Church StreetGrade II
- 6 and 8 Church StreetGrade II
- 6, South StreetGrade II
- 8, Upper SquareGrade II
- 92-96, Twickenham RoadGrade II
- Abbey Barn and Attached Wall and GatewayGrade II
- Boundary Wall to Syon ParkGrade II
Show all 57 listed buildings ↓All 57 listed buildings
- Busch House SchoolGrade II
- Butlers AlmshousesGrade II
- Coach and Horses Public HouseGrade II
- Creek HouseGrade II
- Entrance Gate and Front Wall of Gumley HouseGrade II
- Former Riding School of Syon ParkGrade II
- Front Entrance Gate and Gateposts to Nazareth HouseGrade II
- Garden Pedestal and Vase in Syon ParkGrade II
- Garden Wall at Syon ParkGrade II
- Isleworth Public HallGrade II
- Isleworth War MemorialGrade II
- Memorial to the Pears Family, Isleworth CemeteryGrade II
- Mill Bridge and BasinGrade II
- Nazareth HouseGrade II
- Nazareth House GatehouseGrade II
- Northumberland HouseGrade II
- Ornamental Bridge in Syon Park Over Pond Near Entrance GatesGrade II
- Pair of Chapels at Isleworth CemeteryGrade II
- Park CottagesGrade II
- Porters Lodge at Syon House at Corner of Park Road and Church StreetGrade II
- Railings and Lamp of Number 43 Richard Reynolds HouseGrade II
- Retaining Walls of Garden Pool, And Statue in Syon ParkGrade II
- Sarah Sermons AlmshousesGrade II
- Sir Thomas Ingrams AlmshousesGrade II
- Small Gateway to Syon Park to North East of Park EntranceGrade II
- Stables of Syon ParkGrade II
- Stone Vases in Front of Syon House ConservatoryGrade II
- Sundial (between Farm House Lodges)Grade II
- Sundial at Gumley HouseGrade II
- The Dairy at Syon ParkGrade II
- The George InnGrade II
- The Old Blue SchoolGrade II
- The VicarageGrade II
Streets in the conservation area
Streets with listed buildings inside the boundary. Boundaries often split a street — check your exact address.
Nearby conservation areas
Boundary and listed buildings from London Borough of Hounslow and Historic England via planning.data.gov.uk (OGL). Guidance only — not an official council check.