- Decision
- allowed, 8 September 2026
- Decided by
- Planning Inspector: J Bell-Williamson
- Authority
- St Albans (East of England)
- Appeal reference
- 6010603
- Application reference
- 5/2025/2222
- Procedure
- householder
- Development
- Two-storey side extension replacing single-storey side extension, small rear infill, internal reconfiguration
- Site context
- green belt, washed over village
- Green Belt
- Yes (grey belt not argued)
- Framework applied
- August 2026 NPPF
- Determinative policies
- GB7(1)(b)
- Development plan policies
- St Albans District Local Plan Review 1994 Policies 1, 13, emerging LP Policy LG9
- Main issues
- inappropriate development; VSC
Summary
Two-storey side extension to a detached house in a residential road washed over by the St Albans Green Belt. Allowed. The cumulative floorspace increase of about 39-42% was "not insignificant", but the extension was set down, set back and narrow, and sat largely on an existing single-storey footprint. It was therefore not disproportionate under GB7(1)(b), and openness did not need separate assessment.
Issues and findings
- Transition. The new Framework "does not alter my conclusion" (DL ¶2).
- Old local policy. The 1994 policies and SPG "do not reflect the Framework's approach … the more recent national policy should be the principal basis" (DL ¶10-11).
- GB7(1)(b): PASS. "the previous and proposed extensions result in a not insignificant change to the original building's size in quantitative terms … However, this must be balanced with the finding that the proposed extension would not alter the footprint or external dimensions of the dwelling to the extent that it would be disproportionate" (DL ¶14).
- Openness. "impact on openness is implicitly taken into account in the Framework's exceptions unless there is a specific requirement to consider the actual effect on openness" (DL ¶16).
Planning balance
Not inappropriate, so no VSC balance.
What made the difference
Design subservience: the extension sat on the existing footprint, was set down and set back, and had a limited frontage width. That outweighed a roughly 40% cumulative floorspace uplift.
Transferable points
- A cumulative floorspace uplift of around 40% is not automatically disproportionate. Bulk and external dimensions carry the judgement (DL ¶12-15).
- Where GB7(1)(b) is met, openness is not separately assessed, because it is built into the exception (DL ¶16).
- Pre-Framework local Green Belt extension policies based on visual impact tests are given way to national policy (DL ¶10-11).
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) | pass | cumulative uplift about 39-42% floorspace (176 m3) "not insignificant", but set-down, set-back, narrow extension on existing footprint adds little bulk; not disproportionate (DL 12-15) | |
| GB6(2) | not-engaged | not inappropriate; openness implicitly accounted for in the (b) exception so not separately assessed (DL 16) | |
| SADM/LP Policy 13 (1994) | neutral | 1994 policies and SPG assess scale and visual effect, do not reflect Framework approach; Framework the principal basis (DL 10-11) |
Key facts
- Original floorspace about 149 m2; previous additions about 25 m2 plus proposed 37 m2 (DL 12)
- Residential road of similar two-storey detached houses (DL 8)
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.