Dr Jaydeep Bhadra, domestic sector technical manager at CIBSE, explains what CIBSE is doing to raise standards for heat pump design and installation under the Future Homes and Buildings Standard (FHBS)
The publication of the FHBS in March 2026 marks a genuine turning point. For the first time in the history of UK building regulations, new homes must be built with low-carbon heating and on-site renewable electricity as standard. Gas boilers are effectively prohibited in new dwellings. Heat pumps will become the dominant heating technology in new homes built in the UK for years to come.
This is the direction CIBSE has long advocated. But I want to be honest about something that often gets lost in policy announcements: regulations set the floor. They tell the industry what the minimum acceptable standard is. Whether we build homes that genuinely perform well in practice, keep residents comfortable, keep energy bills manageable, and keep systems working efficiently for years to come, will depend on what happens after the regulations are published. Good design, correct installation, proper commissioning, and ongoing maintenance are all essential.
That is what CIBSE’s work in the domestic sector is focused on. And right now, that work is more important and more squarely in the regulatory spotlight than ever before.
Dedicated voice for the domestic sector
Domestic buildings make up the vast majority of the UK’s built environment and contributes 30% of national emissions, the majority of which comes from heating. Yet historically, they have not always received the same level of technical attention as large commercial or public sector projects. As the country moves towards low-carbon heating at scale, that is beginning to change.
While homes may appear simpler to decarbonise than offices or commercial buildings, designing low-carbon heating systems for millions of different properties is far from straightforward. The challenge involves different building types, varying insulation standards, occupant behaviour, local climate conditions and evolving regulations.
That is why CIBSE took a significant step in late 2025 by formally bringing the Domestic Building Services Panel (DBSP) under the CIBSE umbrella. The DBSP, which has been the ‘association of associations’ for the domestic building services industry since 1997, now operates as the CIBSE Domestic Building Services Panel, bringing together 17 member organisations (as of May 2026) from across the technical, regulatory and training sectors.
The panel’s purpose is to improve standards and share best practice across the full lifecycle of domestic building services: from survey and design through to installation, commissioning, operation and maintenance. Its working groups bring together some of the most experienced practitioners in the sector to develop guidance that is technically robust, practical to apply, and up to date with rapidly changing regulations and technologies.
As part of this commitment, CIBSE has created a dedicated role within the Institution to coordinate guidance development, monitor regulatory and policy developments, and ensure that the needs of domestic building services practitioners are represented at the highest levels of CIBSE’s work. The role also reflects CIBSE’s increasing focus on consumer engagement, recognising that informed homeowners play an important role in driving better design quality, clearer communication and improved outcomes across the domestic sector.
Domestic heating guidance
A central focus of CIBSE DBSP’s recent output is the new Domestic Heating Design Guide 2026, the 11th edition of this authoritative publication, now formally cited in the updated Approved Document L (Vol 1: Dwellings).
This formal recognition is significant. It means that every designer and installer working on a new home in England must now have access to, and understanding of, guidance that CIBSE has produced. The Domestic Heating Design Guide is referenced in Section 4.15 of the updated Approved Document L for sizing domestic hot water systems, and CIBSE is named in Section 4.9 as one of the bodies producing authoritative guidance on the design and sizing of space heating and hot water systems.
The guide also introduces expanded options for designing outdoor temperature. Previously, guidance focused on sizing for the coldest day of the year. The new edition includes options ranging from the 99.6th to the 95th percentile for coldest-day temperature, allowing designers to make informed decisions about balancing system performance, efficiency, and installation cost. In many modern, well-insulated homes, this can provide a more proportionate and cost-effective solution.
Perhaps the most significant addition to the new guide is the introduction of the System Criteria Document. This creates a clear written record of the key design decisions for a heating system, including heat-loss calculations, target indoor temperatures, emitter sizing, flow temperatures, and control settings.
In practical terms, this gives both professionals and homeowners greater transparency. If a system is not performing as expected after installation, there is now a documented reference point that explains how and why the system was designed in a particular way.
In the context of the Building Safety Act, which aims to raise the bar for professional accountability and documentation across construction work, this is an important step. It creates a paper trail for performance and accountability.
The Domestic Heating Design Guide 2026 is deliberately heat-generator neutral, providing a framework for any heating system designed to current standards. However, the panel is clear that heat pumps require dedicated guidance of their own, and that guide is now in development.
The forthcoming Domestic Heat Pump Design and Installation Guide (DHPDIG), expected in the third quarter of 2026, will provide a comprehensive resource for specifiers and technicians involved in designing and installing heat pump systems in domestic buildings. It will build directly on the foundations of the Domestic Heating Design Guide and address the technical challenges specific to heat pump systems.
Why heat pump design matters
One of the most important messages for homeowners and the industry alike is that heat pumps are not simply a direct replacement for a gas boiler.
Heat pumps work best when the entire heating system has been carefully designed around them. Unlike traditional boilers, heat pumps are far less tolerant of poor system design or installation shortcuts. System performance depends on a range of factors working together effectively. This includes correct pipe sizing, suitable radiators or underfloor heating, effective controls, good insulation and appropriate operating temperatures.
The DHPDIG will address all of these issues. It will cover the full heat pump lifecycle, from initial site assessment through to design, installation, commissioning and handover, with practical guidance to support designers and installers at every stage of the process.
Empowering homeowners
Homeowners do not need to become heating experts themselves, but understanding which questions to ask can significantly improve the quality of the final installation.
The guidance CIBSE produces for professionals is essential. But informed consumers are also among the most powerful ways to raise standards across the sector. When homeowners engage a heating designer or installer, they rely heavily on professional expertise. However, the heat pump transition is taking place during a period of rapid industry change, where experience levels and approaches can vary significantly.
This creates a risk that some systems may not deliver the comfort, efficiency or running costs homeowners expect. Not because homeowners are expected to do the technical work themselves, but because informed customers are more likely to receive clearer explanations and better service.
That is the thinking behind the new consumer-focused heat pump factsheet, developed by the CIBSE DBSP. It is a free resource that explains, in straightforward language, what a good heat pump installation process should involve and which questions homeowners should ask at each stage.
During the design stage, homeowners should expect a clear explanation of:
- How the property’s heat loss has been assessed
- What temperature the system is designed to operate at
- How radiators or underfloor heating have been selected
- What level of comfort and efficiency the system is expected to deliver
This is where the System Criteria Document introduced in the Domestic Heating Design Guide becomes especially valuable. It gives homeowners a clear record of the design decisions behind their heating system.
If this information cannot be clearly explained or documented, homeowners should feel confident asking further questions before proceeding.
Commissioning and handover
After installation, the factsheet explains what commissioning should involve and why it matters. Commissioning is far more than a box-ticking exercise. It is the process of setting the system up correctly so that it performs efficiently in real-world conditions. This includes balancing heating circuits, configuring controls, verifying hot-water performance, and ensuring weather-compensation settings operate correctly.
A heat pump that is well-designed but poorly commissioned may underperform from day one. The homeowner who understands this is empowered to ask:
- Has the system been fully commissioned?
- Can the commissioning record be provided?
- Have the controls been properly explained?
These are reasonable and important questions that should form part of any professional installation process.
The factsheet has already reached a wider audience beyond the building services industry. CIBSE’s Technical Director, Dr Anastasia Mylona, discussed it on a recent episode of BBC Radio 4’s You and Yours programme, helping bring discussion about heat pumps and home energy systems into the mainstream consumer conversation.
There is a growing public appetite for clear, independent and technically grounded advice on low-carbon heating technologies, in a media landscape that tends toward either uncritical promotion or equally uncritical scepticism.
The bigger picture
The FHBS has provided much-needed clarity about the future direction of home heating in the UK. But policy clarity alone does not guarantee successful delivery. Regulations and guidance in isolation will not be enough without a properly trained and competent workforce.
CIBSE continues to stress that the regulatory framework must be supported by mandatory competence requirements and long-term investment in training. The transition to low-carbon heating is already underway. The challenge now is ensuring the transition delivers real benefits in practice, for homeowners, for the industry, and for the UK’s wider net-zero ambitions.
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