Do Grant heat pumps need planning permission? July 22, 2025 One of the most common questions we’re asked by customers across Hampshire is whether planning permission is needed. The answer is encouraging for most homeowners, in many cases, Grant heat pumps can be installed under permitted development rights. However, recent updates and specific conditions still apply, so it’s worth knowing the latest guidance. Planning Permission and Permitted Development: What’s Changed? Air source heat pumps are classified as permitted development in England as long as certain criteria are met. This means that you don’t always need to go through the full planning application process, which speeds up installation and simplifies your path to lower energy bills. As of 29th May 2025, the Government’s Warm Homes Plan introduced changes that make it even easier to install heat pumps without extra red tape. These new rules are part of an updated section of the Town and Country Planning Order and apply to homes in England. Here’s a breakdown of the changes that now apply to Grant heat pump installations. What Are the New Permitted Development Rules? 1m boundary restriction removed You can now install a heat pump within 1 metre of your boundary on a detached house without needing permission. Larger units are now permitted Outdoor heat pump units can be up to 1.5 cubic metres in volume for houses, and up to 0.6 cubic metres for flats, under permitted development. Noise restrictions apply The system must meet MCS 020 a) noise limits, which assess sound levels next to the nearest neighbouring window or door. If it stays under 37dB(A), you're in the clear. These updates make it far easier for homeowners in Southampton, Portsmouth, and surrounding areas to install efficient systems like the Grant Aerona³ or Aerona 290 without worrying about unnecessary planning delays. Situations Where Planning Permission Is Required Despite the new allowances, there are still certain circumstances where planning permission is necessary. These include: Listed buildings or scheduled monuments Homes in World Heritage Sites, conservation areas, or national parks Installing more than one heat pump on a semi-detached house or block of flats Mounting a heat pump on a flat roof within 1 metre of its edge, or on a pitched roof Adding both a heat pump and wind turbine to the same building For these cases, it’s essential to contact your local planning department before installation begins. Even when your system appears compliant, site-specific factors may influence the final decision. What Makes Grant Heat Pumps a Safe Bet? Grant has carefully designed its heat pumps to meet permitted development guidelines. For example: All R32 and R290 models fall under the 0.6–1.5m³ size limits Units like the Aerona 290 4kW, 6.5kW and 9kW are especially compact The Aerona 290 12kW and 15.5kW models, though larger, still comply at 0.634m³ This means most Grant heat pumps are installation-ready for typical UK homes. The combination of quiet operation and compact design reduces the chance of planning complications, giving homeowners greater confidence when upgrading to renewable heating. Planning to install a Grant heat pump in Southampton, Portsmouth or Hampshire? Clean Heating Solutions are your local experts in heat pump installations that meet all current planning and MCS standards. We’ll assess your property, help you stay within permitted development rules, and install your new Grant heat pump with minimal disruption. Call 07391473964 or fill in our contact form to get a free quote.