- Decision
- dismissed, 4 September 2026
- Decided by
- Planning Inspector: S Ramsden
- Authority
- Windsor and Maidenhead (South East)
- Appeal reference
- 6009260
- Application reference
- 25/03424/FULL
- Procedure
- householder
- Development
- Front gable, front/side and rear/side extensions, raised ridge, six dormers with Juliet balconies to a 1960s semi-detached bungalow
- Site context
- green belt, flood zone 3
- Green Belt
- Yes (grey belt not argued)
- Framework applied
- August 2026 NPPF
- Determinative policies
- GB7(1)(b), GB6(2), DP3, F4
- Development plan policies
- RBWM Borough Local Plan 2022 QP3, QP5, NR1, Horton and Wraysbury NP 2020 NP/HOU1, NP/HOU2, NP/SUSTDEV 02
- Main issues
- inappropriate development; openness; design; flood risk; VSC
Summary
Remodelling of a heavily extended 1960s bungalow into a chalet-style house with a new roof storey and six dormers. Dismissed. At roughly 170-270% of the original it was disproportionate under GB7(1)(b), with limited openness harm, poor design and an inadequate FRA. No VSC.
Issues and findings
- Transition. The changes "do not affect the merits of this case in a material way", so the parties were not consulted (DL ¶2).
- GB7(1)(b): FAIL. "around 170% of the original 1960s bungalow … around 270% if a first floor is included … Both figures indicate a disproportionate addition" (DL ¶9).
- Openness: "localised and limited … Whilst harm to the Green Belt would be limited in nature … it nevertheless attracts substantial weight" (DL ¶13).
- Design and flood risk: conflict (DL ¶17-18, 24).
Planning balance
GB6(2) is "a high hurdle"; the limited considerations do not clearly outweigh (DL ¶27, 30).
What made the difference
Cumulative enlargement well beyond the original building, compounded by poor design.
Transferable points
- Limited, localised openness harm still attracts substantial weight under GB6(2) (DL ¶13, 27).
Policy findings
Policy codes are those of the National Planning Policy Framework (August 2026) unless a development plan is named.
| Policy | Finding | Weight | Note |
|---|---|---|---|
| GB7(1)(b) | fail | ~170% of the original floor area, ~270% with a first floor; significant volume increase (DL 8-10) | |
| GB6(2) | harm | substantial | limited, localised spatial and visual openness harm on an enclosed island site (DL 13) |
| DP3 | conflict | unconvincing roof form, poorly aligned dormers; poor design (DL 14-19) | |
| F4 | conflict | incomplete FRA (Flood Zone 2 or 3), no 1-in-100 plus climate change assessment (DL 20-25) |
Key facts
- Heavily extended 1960s semi-detached bungalow on a small island between branches of the Colne Brook, Metropolitan Green Belt
- New near-flat-roofed upper storey with six dormers on a similar footprint
Sources
This note is one of the decisions behind the NPPF 2026 Navigator, which shows how each Framework test has been applied across all the decisions in the database. Also available as Markdown.