Analysis by the planning data firm found that Barnet refused 61.9% of decided HMO applications during 2024 and 2025. However, just three of 46 HMO appeals were allowed, giving applicants an appeal success rate of 6.5%.
Barking & Dagenham recorded a substantially higher HMO refusal rate of 94%, but had a similar appeal record, with one of 15 decided HMO appeals allowed.
The figures compare with a national success rate of 31.2% across decided change of use appeals, according to the research. PlanningLens also found that a change of use appeal adds a median 238 days to the process nationally.
Mark Broome, founder of PlanningLens, said: "The refusal rate is the number everyone quotes, and in Barnet it looks ordinary for London at 62%. The number that matters once you've been refused is the appeal record; Barnet's is 3 allowed out of 46. That's one in fifteen, the same as Barking & Dagenham, which refuses 94%. Nationally a change-of-use appeal succeeds about one time in three and adds a median 238 days. Both numbers are in the public record. That's where I would look before buying."
The findings form part of PlanningLens research into the growing use of Article 4 directions to control conversions of family homes into small houses in multiple occupation.
Its analysis of the national planning dataset identified 62 HMO related Article 4 directions across 32 English councils as of 7th August 2026.
PlanningLens said there is no central register showing whether individual directions have been confirmed and remain in force. It therefore checked directions against councils' notices, cabinet papers and confirmation decisions.
The research found that eight of the 12 directions confirmed since January 2025 for which coverage could be verified were borough wide or countywide.
Broome said: "There's no national list of which of these directions is actually in force, so we built one. An immediate direction lapses if the council doesn't confirm it within its window. The national dataset does not record that, so we checked all 62 against the councils' own notices. The wave is going big: of the twelve confirmed since January 2025 whose coverage we can verify, eight are borough-wide or countywide. The rewritten NPPF asks for the smallest area that works. Councils are going the other way, and their own cabinet papers say why: the small directions leak."
