Southampton files HMO conversions at 4.5 times the national rate.
Southampton City Council received 1,532 planning applications in 2025 and approved 88.5% of those it decided, slightly above the national rate of 87.6%. The defining feature of the city's planning picture is shared housing: HMO conversions made up 5.6% of applications submitted to Southampton in 2025, against a national average of 1.2%. Owners also build first and ask later at 1.6 times the national rate, with 6.1% of applications submitted after work was already done.
The year in one line
Southampton approves nearly nine in ten applications, files HMO conversions at four and a half times the national rate, and sees retrospective applications at 1.6 times the norm, the unmistakable fingerprint of a large university and rental city.
What Southampton Is Building
Extensions lead, but shared housing sets the city apart.
Home extensions were the most common project type submitted to Southampton City Council in 2025, at 27.0% of all applications, slightly below the national norm of 29.1%. The figure that distinguishes Southampton is HMO conversions: 5.6% of applications, against a national average of just 1.2%. Retrospective submissions and loft conversions also run above the national share. This is the application mix of a large university city with a deep private rented sector.
Applications submitted to Southampton City Council in 2025, by project type.
The shared-housing effect
Southampton files HMO conversions at 4.5 times the national rate. One in every 18 applications was for an HMO, the unmistakable mark of a city built around student and rental demand.
The council verdict
A clear yes, with refusal below the national rate.
Of applications that received a decision, Southampton approved 88.5% and refused 11.5%, with refusal running below the national rate of 12.4%. That is roughly 1 in 9 applications turned down, compared with 1 in 8 nationally. Both approval and refusal rates are drawn from the pooled 2024-2025 record for stability.
About 1 in 9 Southampton applications was refused.
Southampton applications was refused, against 1 in 8 nationally. The council's 88.5% approval rate sits just above the national average of 87.6%.
Southampton vs The National Norm
A rental city, by the numbers.
Set Southampton's application mix against the national average and the rental effect stands out sharply. HMO conversions appear in 5.6% of applications here against 1.2% nationally, a 4.5x gap. Retrospective submissions and loft conversions also run above the national share. The one category running well below is demolition, at 5.6% compared with 9.1% nationally, reflecting the city's tight urban fabric.
Southampton files HMO conversions at four and a half times the national rate. It is the planning signature of a city with a large student population and a deep private rented sector.
Each bar is Southampton's share of applications submitted in 2025; the marker is the national share. HMO conversions are the city's defining outlier.
Meanwhile, the market
Prices held up alongside the building work.
Permission is no easier or harder to win here than nationally, but prices have continued to climb alongside the steady flow of building work.
Southampton's planning data tells a precise story. The city files HMO conversions at four and a half times the national rate, builds first and asks later at 1.6 times the norm, and the council approves slightly more applications than the national average. This is not a city at odds with its planners. It is a city where rental demand drives the development pipeline, and those numbers show it clearly.
Where the numbers come from
Planning Data
Applications submitted to Southampton City Council in 2025, classified from each application's published description. Shares are each category as a percentage of all applications. Decision rates are drawn from the pooled 2024-2025 record for stability.
Decision Rates
Approval rate is approvals as a share of approvals plus refusals. The national benchmarks are computed the same way across all decided applications in England and Wales.
Sales Data
HM Land Registry Price Paid Data for the Southampton post town, the latest full year's completions, with growth measured against the previous year.
The Real Applications
Open the planning applications behind the numbers.
These are real applications submitted to Southampton in 2025, from an HMO conversion and retrospective submissions to extensions and refusals. Open any one to see its full record.
210b Bassett Green Road SO16 3NF
An existing garage was converted into a self-contained residential annex, part of the loft and outbuilding activity that runs above the national share in Southampton.
See this property's full recordFlat 7 Avondale House 33 Carlton Crescent SO15 2EW
Listed-building consent was granted to brick up a bedroom doorway in a protected building, the heritage work Southampton does less often than the national norm.
See this property's full record25 Lime Avenue SO19 8NY
A single-storey rear extension with a hip-to-gable roof change and rear dormer to create a loft conversion was approved subject to conditions.
See this property's full record32 Estridge Close, Bursledon SO31 8FN
A single-storey side extension with a garage and workshop, already built, was kept under a retrospective application, the build-first pattern Southampton files at 1.6 times the national rate.
See this property's full record88 Hammonds Green, Totton SO40 3HT
A bid to certify a rear extension as not needing permission failed, with the council finding the proposal was not lawful development.
See this property's full record81 Cromer Road SO16 9HR
A single-storey rear extension together with an outbuilding in the rear garden was approved subject to conditions.
See this property's full recordCurious about a home in Southampton?
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