About the Smith Square Conservation Area
The Smith Square Conservation Area covers about 10 hectares and was designated by City of Westminster in 1987. Inside the boundary are 76 listed buildings (1 Grade I, 24 Grade II*, 51 Grade II). The most significant is St. John's Smith Square, Grade I. 1 Article 4 direction over the area removes further householder rights, on top of the conservation area limits below. 11 Tree Preservation Order records overlap the area; every other tree here still needs six weeks’ notice before work. 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.
- Article 4 Basement Development Permitted Rights RemovedHouseholder works
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.
- St. John's Smith SquareGrade I
- 1 and 2 Millbank, The Church Commissioners (including No 3 Great College Street, No 2 Great Peter Street and Nos 5 and 7 Little College Street)Grade II*
- 1 and 2, Smith Square Sw1Grade II*
- 1, Barton Street Sw1Grade II*
- 1, Cowley Street Sw1Grade II*
- 11-14, Barton Street Sw1Grade II*
- 13-19, Lord North StreetGrade II*
- 13, Cowley Street Sw1Grade II*
- 14, Cowley Street Sw1Grade II*
- 15, Cowley Street Sw1Grade II*
- 16 and 17, Cowley Street Sw1Grade II*
- 16, Great College Street Sw1Grade II*
- 17 and 18, Great College StreetGrade II*
- 18, Cowley Street Sw1Grade II*
- 19, Cowley Street Sw1Grade II*
- 19, Great College Street Sw1Grade II*
- 2 and 3, Cowley Street Sw1Grade II*
- 3-5, Smith Square Sw1Grade II*
- 3, Barton Street Sw1Grade II*
- 4-6, Barton Street Sw1Grade II*
- 6, Smith Square Sw1Grade II*
- 7-9, Smith Square Sw1Grade II*
- 9 and 10, Barton Street Sw1Grade II*
- 9, Little College Street Sw1Grade II*
Show all 76 listed buildings ↓All 76 listed buildings
- Numbers 2, 4, 5, 7, 8, 10 and 11, Lord North StreetGrade II*
- 1, Dean Trench Street Sw1Grade II
- 10 and 11, Gayfere Street Sw1Grade II
- 10-12, Little College Street Sw1Grade II
- 13 Stone Bollards on Pavement Curb Surrounding St John's Smith Square Concert HallGrade II
- 17-21, Gayfere Street Sw1Grade II
- 2 AND 4, DEAN TRENCH STREET SW1 (See details for further address information)Grade II
- 2 Bollards Flanking Junction of Smith Square and Lord North StreetGrade II
- 3, Dean Trench Street Sw1Grade II
- 36, Smith Square Sw1Grade II
- 37, Smith Square Sw1Grade II
- 4, Cowley Street Sw1Grade II
- 57 and 57A Tufton StreetGrade II
- 62 AND 64, HORSEFERRY ROAD SW1 (See details for further address information)Grade II
- 7 Lampstandards Numbered G4, 5 and 6 and G9, 10, 11 and 12Grade II
- 7, Gayfere Street Sw1Grade II
- 8, Barton Street Sw1Grade II
- Corner HouseGrade II
- Faith HouseGrade II
- Gayfere LodgeGrade II
- Lamp post adjacent to 14 Great College StreetGrade II
- Lamp post next to 3 Dean Trench Street and outside 36 Smith SquareGrade II
- Lamp post on corner of 13 Gayfere Street and 1 Smith SquareGrade II
- Lamp post on corner of 3 Great College Street and 5 Little College StreetGrade II
- Lamp post on corner of 81 Tufton StreetGrade II
- Lamp post on corner of Tufton Street and 2 Dean Trench StreetGrade II
- Lamp post opposite 7 Cowley StreetGrade II
- Lamp post outside 1 Cowley StreetGrade II
- Lamp post outside 1 Dean Trench StreetGrade II
- Lamp post outside 11 Gayfere StreetGrade II
- Lamp post outside 11 Lord North StreetGrade II
- Lamp post outside 12 Cowley StreetGrade II
- Lamp post outside 15-16 Lord North StreetGrade II
- Lamp post outside 16 Great College StreetGrade II
- Lamp post outside 2 Dean Stanley StreetGrade II
- Lamp post outside 2 Lord North StreetGrade II
- Lamp post outside 20 Great College StreetGrade II
- Lamp post outside 22 Gayfere StreetGrade II
- Lamp post outside 22 Great College StreetGrade II
- Lamp post outside 3 Barton StreetGrade II
- Lamp post outside 57b Tufton StreetGrade II
- Lamp post outside 7-9 Dean Bradley StreetGrade II
- Lamp post outside 8 Barton StreetGrade II
- Lamp post outside Tufton CourtGrade II
- Lampstandard Numbered G1Grade II
- Lampstandard Numbered G1 on Corner of Smith SquareGrade II
- Lampstandard Numbered G1 on Corner of Smith SquareGrade II
- No. 22 Great College Street (including St Edward's Chapel, Tufton Street)Grade II
- North House and Gayfere House Including 22 and 23 Gayfere StreetGrade II
- Norwest HouseGrade II
- Thames House (north and South Blocks With Bridge Link)Grade II
- Thorney HouseGrade II
Streets in the conservation area
Streets with listed buildings inside the boundary. Boundaries often split a street — check your exact address.
The council’s appraisal
WEBSmith Square Conservation Area AppraisalCity of Westminster’s description of the area’s character — what planners look at when you apply.Open on council site ↗Nearby conservation areas
Boundary and listed buildings from City of Westminster and Historic England via planning.data.gov.uk (OGL). Guidance only — not an official council check.