Slough files loft conversions at 4.6 times the national rate. And 1 in 6 applications is refused.
Slough Borough Council received 1,263 planning applications in 2025 and refused 18.0% of those decided, against a national refusal rate of 12.4%. That is roughly 1 in 6 applications turned down, compared with about 1 in 8 nationally. The town also builds first and asks later: 7.3% of applications were retrospective, nearly twice the national rate.
The year in one line
Slough files loft conversions at 4.6 times the national rate, outbuildings at 3.9 times, and retrospective applications at 1.9 times, while refusing 1 in 6 applications submitted to the council, above the national rate.
What Slough Is Building
Extensions dominate, with outbuildings, dormers and lofts close behind.
Home extensions were by far the most common application submitted to Slough Borough Council in 2025, at 45.6% of the total, against a national share of 29.1%. Outbuildings followed at 12.5%, dormers at 11.9% and loft conversions at 11.9%, all well above national norms. Retrospective applications, for work already carried out, made up another 7.3%. This is the application mix of a borough adding space to existing homes, with the roof and the rear garden doing most of the work.
Applications submitted to Slough Borough Council in 2025, by project type. Counts are from the 2024-2025 pooled window used for share calculations.
The roof effect
Slough files loft conversions at 4.6 times the national rate and dormers at 2.0 times. Both are roof projects on existing homes, the favoured way to add space where the footprint is fixed.
The council verdict
A harder yes to win than most.
The council approved 82.0% of the applications it decided and refused 18.0%, against a national refusal rate of 12.4%. That is roughly 1 in 6 applications turned down, compared with about 1 in 8 nationally. Permission here is harder won than in most of the country.
Roughly 1 in 6 Slough applications was turned down.
of applications were refused, against a national rate of 12.4%. Slough turns down roughly 1 in 6 applications, where the country turns down about 1 in 8.
Slough vs The National Norm
A borough that builds up, builds out, and often asks afterwards.
Set Slough's application mix against the national average and several things stand out. Loft conversions run at 4.6 times the national share, outbuildings at 3.9 times and dormers at 2.0 times. Retrospective applications, for work already built, run at 1.9 times the national rate. Where Slough does less is heritage: listed-building works feature in just 0.4% of applications, a fraction of the national share, reflecting a town with very little protected building stock.
Slough files loft conversions at 4.6 times the national rate. With footprints fixed, owners build into the roof to add space, then a notable share apply only after the work is done.
Each bar is Slough's share of applications submitted to Slough Borough Council in 2025; the marker is the national share. Loft conversions are the town's defining outlier.
Meanwhile, the market
Prices rose alongside the building work.
Permission may be harder to win here than the national norm, but prices kept climbing: the average Slough home sold for more in the latest full year than the year before.
Slough's planning data tells a clear story. This is a borough where owners are hungry for space, filing loft conversions at 4.6 times the national rate and outbuildings at 3.9 times. The council refuses 1 in 6 applications, above the national rate. A notable share of owners apply only after the work is built. For anyone planning improvements here, the message is straightforward: get permission first.
Where the numbers come from
Planning Data
Applications submitted to Slough Borough Council in 2025, classified from each application's published description. Shares are computed over the pooled 2024-2025 window for stability; volume is the 2025 count.
Decision Rates
Approval rate is approvals as a share of approvals plus refusals, across applications decided in 2024-2025. 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 Slough 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 Slough Borough Council, from loft conversions and outbuildings to refused dormers and retrospective extensions. Open any one to see its full record.
54 Haymill Road SL1 6NF
A lawful development certificate was granted for a loft conversion with a rear dormer and front rooflights, the roof project Slough files most often.
See this property's full record31 Cockett Road SL3 7TQ
A proposed two-storey side extension was turned down, one of the roughly 1 in 6 applications the council refused.
See this property's full record11 Cranbourne Road SL1 2XF
Permission was confirmed for a loft conversion into habitable space with a rear dormer and rooflights, the kind of roof work that sets Slough apart nationally.
See this property's full record19 Oatlands Drive SL1 3EH
A part single, part two-storey side and rear extension was refused, against a borough refusal rate above the national norm.
See this property's full record5 Blandford Road South SL3 7RT
A front porch with single and two-storey extensions was approved with conditions, the extension work that tops Slough's application mix.
See this property's full record12 Hillside SL1 2RW
A lawful development certificate was granted for a detached outbuilding in the rear garden, one of 336 outbuilding applications filed in the area.
See this property's full recordCurious about a home in Slough?
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