Hertsmere: cooling planning decisions

The record here is thin but publishable: 20 determined applications whose description names a condenser, air conditioning or similar plant, 20 approved and 0 refused.

Hertsmere's record holds 9 more that never reached a determination, whether because they remain live or because the applicant pulled them. Everything below excludes them, so the rate describes determined cases only.

As a rate, 100% of 20 decisions spanning all development types, including 13 householder applications, were approvals. Refusal is close to a rarity on the record here, with the same caveat everywhere: applications abandoned before a decision never enter the count.

The scope matters as much as the number. Commercial and mixed-use plant makes up a large share of any council's cooling caseload, so an all-development rate is a weaker guide to a domestic application than its size suggests.

We stop short of a householder-only percentage for Hertsmere. At 13 decided householder applications the sample is too thin, and a rate drawn from it would read as far more certain than the evidence allows.

The air-to-air heat pump, which heats as well as cools and is the only equipment that can be permitted development on a house, appears in none of Hertsmere's decided applications by name. Nationally the count is similarly close to zero: this is a category planning departments have barely met.

Since 2025-05-29, England's permitted-development rules let a house fit an air-to-air heat pump, which heats as well as cools, without a planning application in many cases, within set size, siting and noise limits. A unit that only cools has no equivalent route and needs a full application whatever the property.

That is why the decisions above matter more than they would have before the change. Every cooling-only installation now crosses a planning officer's desk, so the council's posture is not background information, it is the decision.

Flats are the sharpest exception, here as everywhere in England: the permitted-development right for an outdoor unit belongs to the house rather than to a flat within it, so a flat will usually need freeholder or managing-agent consent as well as planning permission.

What those refusals were FOR is a national question at the volume of officer reasoning currently published, not a council-level one, and we do not pretend otherwise. Both findings are set out with their sample sizes: why cooling applications get refused and the conditions councils attach to an approval.

Every council we can publish a figure for is listed on the council index.

Applications are identified from their own description, so every count on these pages means applications mentioning cooling equipment, not every cooling installation in the area. An application that fitted the same kit but described it as external plant is not in these figures, which makes them a floor on activity rather than a census.

Each application is assigned to Hertsmere through the postcode on the application itself. Of the 29 applications recorded for this authority, 100% carry a location we could resolve; nationally 1682 of 18427 applications could not be tied to a district at all and sit outside every figure on this site rather than being quietly assigned somewhere.

What this page cannot tell you is what will happen at your address. It has no view of your elevation, your neighbours' windows, whether your home sits in a conservation area, or whether it is a listed building - and a neighbour's approval settles none of those. This is indicative guidance drawn from public planning records, not legal advice: confirm the final position with your Local Planning Authority before you install.