Side extensions in Barking and Dagenham depend on the house. Typical homes here: Interwar Becontree estate cottages (LCC, 1920s–30s) in Dagenham, Becontree and Chadwell Heath; 1930s terraces and semis in Marks Gate, Rush Green borders and along Longbridge Road. Designations to check first: Conservation areas; Flood risk: Thames, Roding and Beam; Green Belt and Metropolitan Open Land. Applications are decided by London Borough of Barking and Dagenham and the Barking and Dagenham Local Plan 2037.
The permitted development rules for side extensions
A single-storey side extension is permitted development on a house if it is no wider than half the width of the original house, no higher than 4 m, with eaves no higher than 3 m where it comes within 2 m of a boundary, and finished in materials similar in appearance to the house.
Anything wider than half the original house, any two-storey side extension, and any side extension on a flat needs planning permission. Garage conversions that keep the walls are usually permitted development; extending beyond them is assessed as a side extension.
What changes in Barking and Dagenham
Side extensions are not permitted development in a conservation area at all, so there a planning application is always required.
The local constraints that most often decide the route in Barking and Dagenham are listed below, taken from our Barking and Dagenham area page. Each one is a reason to confirm the address on Barking and Dagenham's constraints map before relying on permitted development.
- Conservation areas. Barking and Dagenham has only a small number of conservation areas, centred on Barking Abbey and the town centre and a handful of historic pockets. Source
- Flood risk: Thames, Roding and Beam. Land along the Thames (Barking Riverside, Thames View, Creekmouth), the River Roding and the Beam River sits in Flood Zones 2 and 3. Source
- Green Belt and Metropolitan Open Land. Eastbrookend Country Park, The Chase and the Dagenham corridor include Green Belt and Metropolitan Open Land, where outbuildings and larger extensions face a much higher bar. Source
- Article 4 directions. We are not aware of a borough-wide Article 4 direction removing householder PD rights, but the council may have made directions on specific estates or for houses in multiple occupation (HMOs). Source
What Barking and Dagenham planning officers look for
Common refusal reasons are over-deep single-storey extensions that box in a neighbour's kitchen window, and loft dormers that run almost the full width of the roof. The council generally offers a paid pre-application service, which we recommend for anything in a conservation area or on a corner plot. Decision times usually sit close to the statutory 8 weeks but can run longer.
Fees and timelines
Barking and Dagenham decides a householder application or a Lawful Development Certificate within 8 weeks of validation. The council fee is £528 for a householder application and £264 for a Lawful Development Certificate (England, from 1 April 2025; verify before applying).
Our own fee is fixed once quoted. The quote tool gives an indicative figure in minutes and a written quote follows within 24 hours.
Primary sources
- The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2: the permitted development limits quoted above.
- Planning Portal: do you need permission: the national guidance and the application service every council accepts.
- London Borough of Barking and Dagenham: planning: the council's own constraints map, validation checklist and pre-application service.
