By Steve Richmond, Sales & Marketing Director, Building Solutions at REHAU UK
The UK’s transition to low-carbon heating is no longer a distant ambition, but a regulatory reality. With the Future Homes Standard due to come into effect this Autumn, the installation of gas boilers in new homes will be phased out, prompting a fundamental rethink of how new build residential developments are heated. At the same time, the Department for Energy Security and Net Zero is rolling out designated heat network zones, and OFGEM is gearing up to regulate heat networks. This is all while the Climate Change Committee projects that 18% of the UK’s heat demand could be met by heat networks by 2050.
This shift comes at a time of significant growth in the housing sector, with the Government committing to building 1.5 million new homes over the course of the current parliamentary term. This is a target that will require not only speed and scale, but also a rethink of how these homes are heated. For housebuilders, this presents both a challenge and an opportunity. Namely, how to confidently integrate low carbon heating – either in the form of individual heat pumps, or a district heating network using large, centralised heat pumps – into new developments in a way that is futureproof, efficient, and commercially viable.
With both of these options offering differing advantages, district heating offers housebuilders the added bonus of ease of scalability. While the technology is not new, for many developers it remains unfamiliar territory, particularly when it comes to the installation process and end user experience. Yet with the right knowledge and support, housebuilders can not only meet regulatory requirements but also deliver high-quality, low-carbon homes that appeal to increasingly sustainability-conscious buyers and meet continually tightening environmental legislation.
Historically, many large-scale city centre networks have used steel pipework for these networks. However, new build networks are ideally suited to modern polymer pipes, which are delivered in large coils, and can be installed easier and faster than steel networks. In addition, utility contractors, already working on these projects can be upskilled to install polymer district heating pipes, offering a one-stop multi-utility solution.
Designing for Flexibility and Efficiency
The first thing to understand when considering district heating for a new housing development is design.
For heat networks, a 4th generation model, with a single energy centre distributed via pre-insulated pipework to multiple buildings is the most common solution. This approach benefits from simple maintenance, with an external plant to maintain, and the opportunity of economies of scale for the larger centralised heat pump. Here, careful planning is key to ensuring heat losses are mitigated between the heat source and individual homes, further underlining the importance of pipework material choice during the design phase. Giving consideration to not just installation but long term reliability and performance during operation.
Any design must also account for future scalability and demand, energy efficiency, and integration with renewable sources. It’s therefore imperative that suppliers work closely with heat network designers and operators on optimising a network design, whether through pipe sizing, heat loss calculations, pipe layout and reducing material costs where possible.
Understanding the Jointing Landscape
Beyond this, one of the most critical aspects of district heating infrastructure is the method used to join the pipework. The choice of jointing technology can significantly impact installation speed, system reliability, and long-term performance.
There are three main jointing methods used in polymer-based district heating systems – compression sleeves, electrofusion and butt-welding. Each has its place, and understanding their differences is key to making informed decisions on site.
Compression sleeve systems for flexible PE-Xa (cross-linked polyethylene) pipes offer a fast-fitting, non-welded solution which is particularly well-suited to residential developments. These joints are created in the trench by expanding the pipe and then mechanically compressing a sleeve over the pipe and fitting, forming a permanent, leak-proof connection with no O-ring. Compression sleeve systems such as REHAU’s EVERLOC have been installed over 1 billion times worldwide, chosen for their reliability and simple visual inspection to check the joint is done correctly.
As an alternative jointing method for PE-Xa pipes, there are specially designed electrofusion fittings for district heating pipes which can take higher temperatures, that may be required. Some utility contractors prefer using electrofusion as it’s a standard jointing for gas and water pipes. Electrofusion does, however, take longer to install and requires additional preparations compared to a compression sleeve system.
When it comes to large diameter pipes, PP-R (reinforced polypropylene) pipes are used on polymer heat networks. These come in straight sticks and are typically joined by butt welding. Again, this is a common process that utility contractors will be familiar with from large diameter water and gas mains.
Every underground joint within a heat network must be insulated with the same high performance polyurethane foam as the pipe itself to prevent heat loss. These critical articles, called shrouds, securely encase the joint and are filled on site with PU foam. If a shroud is installed incorrectly, these can cause water ingress and potentially cause increased heat losses and pipe failure due to corrosion, especially in the case of traditional steel pipe and fittings. The two most common types of shrouds used are heat shrink shrouds, which require hot works and clip-shrouds (such as REHAU’s CLIP-FLEX shroud), which do not require hot works.
Supply Chain Support and On-Site Realities
As with any construction project, the success of a heat network project depends not just on design but on execution. This is where the supply chain plays a vital role – from ensuring UK-based stock availability to providing on-site technical support, manufacturers can help housebuilders navigate the complexities of district heating with greater confidence.
For example, some manufacturers offer practical installation training to become accredited installers, alongside CIBSE-accredited District Heating CPD sessions for heat network designers to build technical knowledge. These resources are particularly valuable in a market where in-house expertise may still be developing. With the Construction Industry Training Board forecasting a shortfall of nearly 240,000 workers needed to meet housing targets, simplifying installation and reducing reliance on specialist trades is more important than ever.
Moreover, logistical considerations such as delivery schedules, storage requirements, and weather protection during installation can all impact project timelines. Choosing polymer systems that arrive in coils which are easy to handle, quick to install, and supported by responsive technical teams can make the difference between a smooth rollout and costly delays.
Building Confidence in a Changing Market
The shift to low-carbon heating is moving from an interesting option to a regulatory and environmental imperative. But for housebuilders, it also represents a chance to add another selling point to their developments while meeting evolving buyer expectations and contributing meaningfully to the UK’s decarbonisation goals. Implemented correctly, district heating offers a scalable, efficient solution that nonetheless aligns with the country’s net zero legislative requirements.
By understanding the nuances of pipe materials, jointing and shroud technologies, staying informed on design trends, and leveraging the support available from experienced suppliers such as REHAU, developers can approach this transition with confidence. As the market matures and heat networks become a standard feature of new housing, housebuilders who build knowledge and supply chain relationships today will be best positioned to benefit tomorrow.