# 38 Brook Lane, Corfe Mullen

- **Decision:** dismissed, 24 August 2026
- **Decided by:** Planning Inspector: D R Kay
- **Authority:** Dorset (South West)
- **Appeal reference:** 6007369
- **Application reference:** P/HOU/2025/06963
- **Procedure:** householder
- **Development:** Extension to existing annexe (living room) and flue
- **Site context:** green-belt
- **Green Belt:** yes (grey belt not-argued)
- **Framework applied:** August 2026 NPPF
- **Determinative policies:** GB7(1)(b), GB6(2)
- **Development plan policies:** East Dorset Local Plan 2002 saved GB3, Christchurch and East Dorset Core Strategy 2014 KS3, HE2
- **Main issues:** inappropriate development, openness, VSC
- **Tags:** disproportionate-extension, householder, vsc-not-shown, openness-harm, garden-not-pdl, psed-considered, fallback-not-evidenced, drafting-slip

## Summary
Small, screened extension to an annexe at a much-extended dwelling. Dismissed. Cumulative additions already exceeded 100% of the original building, so the extension was disproportionate under GB7(1)(b). Garden land is not PDL, so (e) did not apply. There was moderate openness harm. Multi-generational and PSED considerations did not amount to VSC.

## Issues and findings
- **Transition.** The relevant matters were "substantially unchanged", so the appeal was decided under the 2026 Framework without consultation (DL ¶3). One of the earliest 2026 GB decisions (24 Aug 2026).
- **GB7(1)(e): FAIL.** "the site is within the garden curtilage of a residential dwelling. As such, it would not meet the definition of PDL in Annex B" (DL ¶9). The letter then refers to "the GB7(1)(g) exception", which appears to be a slip for (e).
- **GB7(1)(b): FAIL.** "Cumulatively, the floor area of the original building has therefore already been enlarged by significantly more than 100% … would represent disproportionate additions" (DL ¶13). The saved local policy likewise bars "a succession of 'limited' extensions which cumulatively form a substantial extension" (DL ¶14).
- **Openness: moderate harm** in both visual and spatial terms, despite screening (DL ¶16).
- **PSED.** The existing annexe already provides independent living, so the benefit is outweighed (DL ¶19-21).

## Planning balance
GB6(2): the other considerations were "not sufficient to comprise the very special circumstances" (DL ¶23).

## What made the difference
Planning history. The original bungalow had been doubled and the garage more than doubled, so even a small infill addition was disproportionate.

## Transferable points
- Residential garden curtilage is not PDL for GB7(1)(e) (DL ¶9).
- Screening from public views does not remove openness harm (DL ¶15-16).
- An unevidenced permitted development fallback carries little weight (DL ¶22).

## Policy findings
- **GB7(1)(b): fail.** original bungalow doubled by a 1987 upward extension; garage enlarged ~110% in 1993 then converted to an annexe; cumulative increase well over 100%, so any further addition is disproportionate (DL 10-13)
- **GB7(1)(e): fail.** residential garden curtilage is not PDL under Annex B (DL 9)
- **GB6(2): harm (substantial weight).** moderate visual and spatial openness harm even though screened from public views (DL 16)
- **Equality Act s149: neutral.** multi-generational and protected-characteristic need considered; existing annexe already meets needs; outweighed (DL 19-21)

## Key facts
- Original bungalow and detached double garage; 1987 second storey; 1993 garage to four-car; 2021 conversion to a two-bed annexe
- Small extension in the internal corner, substantially screened from the public realm
- Permitted development fallback unevidenced, so little weight

## Sources
- https://appeal-planning-decision.service.gov.uk/comment-planning-appeal/appeals/6007369
- https://appeal-planning-decision.service.gov.uk/published-document/527d0d2a-3749-4b31-a8cd-6a9902d232eb

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