Single storey extensions

Planning constraints we check

A single storey extension looks simple, but most refusals come from a constraint that was missed at the start: a neighbour's window, a tree root area or a rule in the design guide. We check each of these before drawing.

• Local Plan policies: Reading Borough Local Plan 2019 (CC7 design, CC8 amenity, H9 house extensions, H11 garden land); Wokingham Core Strategy CP3 and the Managing Development Delivery Local Plan (TB06 garden land); the Bracknell Forest Local Plan; West Berkshire Local Plan Review 2023 to 2041 (SP7 design quality); Spelthorne Core Strategy and Policies DPD 2009 (EN1); Slough Core Strategy and saved Local Plan policies; and the National Planning Policy Framework.
• Design guidance: The Wokingham Borough Design Guide SPD, Reading's Residential Conversions SPD and design guidance, the Slough Residential Extensions Guidelines SPD and the Bracknell Forest Design SPD, which set rules on scale, roof form, materials, set backs and separation distances.
• Neighbour amenity: Daylight and outlook tested with the 45 and 25 degree methods in BRE 209 (Site layout planning for daylight and sunlight), overlooking distances, overshadowing and the effect of new windows on neighbours' privacy.
• Permitted development and Article 4: Classes A to E of Part 1 of the General Permitted Development Order 2015, prior approval for larger rear extensions, and Article 4 directions that remove permitted development rights in parts of Reading, Wokingham and West Berkshire.
• Trees: Tree Preservation Orders and conservation area trees, root protection areas, and tree surveys, arboricultural impact assessments and protection plans to BS5837:2012 where building works come close to trees.
• Ecology and biodiversity: Bat and nesting bird checks under the Conservation of Habitats and Species Regulations 2017, preliminary roost assessments where roofs or old buildings are affected, and Biodiversity Net Gain under the Environment Act 2021 with the statutory biodiversity metric (householder applications are exempt).
• Flood risk and drainage: The Environment Agency flood map (Flood Zones 1 to 3), site specific flood risk assessments, the sequential test for new homes in higher risk zones, and sustainable drainage (SuDS) for surface water.
• Heritage: Listed buildings and conservation areas under the Planning (Listed Buildings and Conservation Areas) Act 1990 and NPPF chapter 16, with heritage statements where needed.
• Community Infrastructure Levy: CIL liability under the Community Infrastructure Levy Regulations 2010 for new homes and extensions over 100 square metres, with self build and residential extension exemptions claimed before work starts.