HydroTop™ is a roof-integrated casement system that houses an air-source heat pump within the roof void, making installation viable in millions of UK homes where a conventional external unit simply cannot go.
Terraced properties, conservation area houses, and homes with limited external space represent a substantial share of the UK housing stock, and they are precisely the properties where the Warm Homes Plan's ambitions are hardest to deliver.
Space, planning, noise, and aesthetics combine to make a conventional external installation impractical or impossible. This is the single biggest practical barrier to the UK's heat pump rollout, and until HydroTop™, the market had no adequate answer.
Terraced properties and those with limited garden or facade access have nowhere to put a conventional ground or wall-mounted external unit.
External heat pumps generate neighbour objection on acoustic grounds, a consistent barrier in dense urban and suburban housing.
Conservation areas and Article 4 directions prevent or complicate the placement of visible external units on many properties.
The visible external unit is one of the most common sources of homeowner reluctance, an aesthetic barrier that delays or kills installations entirely.
HydroTop™ is a prefabricated, insulated casement system installed between and across the roof rafters. The heat pump sits level within the casement regardless of pitch, with the only external element a low-profile aluminium cap projecting no more than 150mm above the roof surface.
Compatible with all major heat pump manufacturers up to 10kW, installers and programme managers retain full freedom to choose the most appropriate unit for each property.
The complete system arrives pre-assembled. Installation is typically completed within a day. All servicing is carried out from inside the loft, in any weather. Independent testing by Enertek International confirms performance at least equivalent to a conventional external installation.
The low-profile cap can be powder coated to match the surrounding roof. One would not even know the heat pump is there.
Designed to meet Class C of the GPDO. In most cases no formal planning application is required, including many conservation area settings.
Works with all major heat pump brands up to 10kW. HydroTop™ enables the heat pump industry, it does not compete with it.
Housing the unit within the roof structure significantly reduces perceived external noise. Substantially lower neighbourhood impact compared to a conventional external heat pump.
The pre-assembled unit is placed within a day. Servicing is carried out entirely from the loft, whatever the weather.
The casement unit is manufactured from recycled materials, reinforcing an already compelling low-carbon proposition.
HydroTop™ unlocks the dense terraced stock that makes up much of the UK's social housing estate, reducing abortive costs, improving programme viability, and supporting delivery under the Warm Homes Plan.
Find out more →Reduce the number of properties excluded from a programme on grounds of installation complexity. Embedded as a standard solution, HydroTop™ becomes a reliable specification programme managers can count on.
Find out more →HydroTop™ is an addition to your existing offer, allowing you to take on work you would otherwise decline. We work with a network of trusted installation partners across the UK.
Find out more →Specify HydroTop™ from the outset and remove the risk of later redesign. We provide specification support and technical documentation suited to design and planning submissions, including conservation area and PAS2035 contexts.
Find out more →Inbox Thermal Solutions Ltd holds exclusive UK distribution and representation rights for HydroTop™ under a formal collaboration agreement with HydroTop Works B.V., the Dutch manufacturer. We are the operational and commercial engine for HydroTop™'s UK market entry, spanning market development, regulatory certification, installer ecosystem development, and managed end-to-end installation delivery.
A structured regulatory pathway is being actively progressed. Independent performance testing has been completed by Enertek International. We are in active engagement across the key compliance requirements for UK deployment at scale.
Whether you are an installer looking to expand your offer, a housing provider exploring programme options, a retrofit coordinator working on a challenging specification, or an investor interested in the opportunity, we would like to hear from you.