As the race toward net zero intensifies, the conversation is shifting from big-ticket systems to the quieter, high-impact technologies that enhance whole-house efficiency.
One such solution is wastewater heat recovery (WWHR)—a passive, maintenance-free approach that’s increasingly being explored by housebuilders, as it provides extremely cost-effective improvements in SAP performance and energy savings to the householder.
A recent technical exchange between a major UK housebuilder and the team behind Zypho, a specialist in WWHR systems, highlights why this technology is moving up the specification list.
Unlocking Efficiency Where It’s Often Lost
Zypho’s latest system, the Slim 50, is designed specifically for horizontal installation beneath showers and baths. Only needing 110mm of vertical space, it is ideal for apartments and compact homes where space is limited. With an efficiency of up to 65%, the Slim 50 can deliver a considerable SAP point benefit, thus contributing meaningfully to Part L compliance.
In addition, Zypho offer the Pipe 65 and Pipe 75 vertical WWHR systems. These larger heat exchangers offer heat recovery efficiencies of up to 82%, and can have a huge impact on hot water usage within the home.
Whichever system is used, the reduction in hot water demand within the home is considerable, since showering accounts for 80 – 85% of domestic hot water use. This can often allow the size of the thermal store tank to be reduced, and even smaller heat pump systems to be selected. Both of these bring considerable capital savings.
In terms of overall energy efficiency, Zypho WWHR products can offer a much cheaper Part L compliance alternative to costly PV installations.
Standard-Setting Compliance, Ready for Scale
All Zypho systems are fully Regulation 4 compliant under the UK Water Supply (Water Fittings) Regulations 1999, a crucial consideration for developers, designers, and water authorities alike. Each system is WRAS-approved and compatible with standard installation methods. The units are passive, require no power supply, and demand no ongoing maintenance—reducing operational complexity and risk.
Products are manufactured in an ISO-accredited facility, and dispatched on next-day delivery nationwide. For housebuilders preferring palletised deliveries directly to regional logistics centres, Zypho offers a streamlined supply chain with significant cost savings over unit-by-unit shipping.
The Zypho Slim50
Flexibility Built In: From Design to Deployment
The Zypho team works directly with design and operations managers to support integration into standardised build types, including:
- Toolbox talks and CPD sessions for site operatives and subcontractors
- BIM files and design toolkits for architects and engineers
- Bespoke installation manuals aligned to client build specifications
The Slim 50’s multi-orientation capability enables it to be installed in a variety of layouts—including diagonally—allowing it to work around centre-foot obstructions in shower trays or bespoke bathroom configurations.
This flexibility is particularly valuable for apartment schemes, where space for vertical drops is constrained and traditional WWHR pipes are harder to accommodate. For these environments, Zypho’s team provides technical design support, and is also working with modular manufacturers and tray suppliers on future iterations.
Backed by Scale, Delivered with Focus
Zypho is backed by Aliaxis, a global leader in advanced water and energy systems, giving it the financial strength and manufacturing scale required for high-volume rollout. Yet it operates with intense customer focus, offering a very high level of technical engagement and support to its housebuilder partners.
The company has supplied thousands of units into residential developments nationwide, including flagship innovation home schemes and modular platforms.
The Case for Dual Supply and Design Resilience
As housebuilders innovate their heating and hot water strategies, particularly with the shift to heat pumps, the need to embed resilient, interoperable systems into designs is critical. During the conversation, both parties emphasised the benefits of dual supply arrangements: reducing risk, supporting competitive procurement, and enabling design teams to accommodate multiple specifications with minimal rework.
Zypho’s Slim 50 and Pipe 65/75 units are designed to fit within the same, or smaller, spatial footprints as comparable systems, meaning little to no redesign is needed when substituting or dual-sourcing across plots or sites.
Conclusion: A Small System with a Big Role to Play
For years, wastewater heat recovery has been the overlooked opportunity in residential sustainability strategies. But that’s changing. With products like Zypho’s Slim 50 and Pipe 65/75 offering measurable SAP gains, zero maintenance, and regulatory compliance out of the box, developers now have a way to quietly boost energy performance—with only minor design changes.
Overall, as the pressure to decarbonise builds, WWHR is proving to be one of the most cost-effective, space-efficient, and practical technologies available to housebuilders today.
To find out more, or to start a conversation about the best WWHR solution for your project, get in touch with us today.
