Around 39% reduction in gas consumption

Carbon reduction of 88,600 kg of CO2

Innovative approach & tailored solutions

"The Mildmay project has been a great success story for Notting Hill Genesis (NHG). NHG and our partners Fairheat have taken what was considered a poorly performing, unreliable, expensive heating system and transformed it into something NHG can be proud of. FairHeat provided invaluable insight and guidance which has resulted in incredible results for the residents and Notting Hill genesis. The results and energy saving have surpassed our expectations and the added system efficiency monitoring has changed an entire way of thinking about heat networks. Prior to this project Heat networks had always felt a bit unloved and underinvested, the Mildmay project opened doors and has highlighted what can be achieved with existing systems when correct design, commissioning and real partnering are utilised."

Daniel Perager

Head of Heat, Energy and Water (Compliance | Assets), Notting Hill Genesis


The Mildmay project was undertaken by FairHeat for Notting Hill Genesis. As part of the Heat Network Efficiency Scheme (HNES) Demonstrator, the project aimed to optimise the heat network at the Mildmay site, which consisted of 139 residential connections, a hospital, and a church. The existing system utilised district heating with central gas boilers and underground pipework connecting the plant room to the blocks. FairHeat had previously conducted an optimisation study, which identified several issues that needed to be addressed.


The study identified three main areas for improvement: poor Heat Interface Unit (HIUS) performance, poor water quality, and complex hydraulic design. These issues resulted in increased cost of heat to customers, overheating, and unplanned outages. Other issues included overheating in dwellings and communal areas, difficulties in managing the complex system at a system-level, and substation equipment prone to leaks and failures.

FairHeat Solution

FairHeat’s solution to the challenges faced by the Mildmay project was multifaceted, collaborative, and innovative. Following the initial Optimisation Study, FairHeat recommended a series of actions to improve the performance and efficiency of the heating system. These included retrofitting to replace poorly performing units, installing Guru System smart meters, recommissioning the space heating system, and upgrading insulation on the pipeline within dwellings. At the network level, substations were decommissioned, commercial connection control valves were installed, and bypasses were closed at the tops of risers.

Assuming the role of Principal Contractor, FairHeat set out to improve the overall efficiency of the site, resolve identified issues, and enable future opportunities for decarbonisation by reducing temperatures. FairHeat’s optimisation methodology was thorough, involving the establishment of performance and reliability Key Performance Indicators (KPIs), conducting a site audit to review operations, gathering data utilising Guru System technology and analysing it, identifying optimisation opportunities, and developing a financial model and business case. The project’s focus was on performance, with clearly defined pass/fail targets primarily determined through the review of operating temperatures during the works. This performance-focused approach ensured that all implemented solutions met the high standards set for the project.
To further enhance the project’s efficiency and effectiveness, FairHeat implemented remote monitoring via Guru Pinpoint. This allowed for real-time assessment of the system’s performance and enabled immediate adjustments as needed, ensuring optimal operation at all times.

Within the plant room, specific measures were implemented to maintain the minimum temperatures required for the healthcare facility, which were higher than those needed for residential areas. However, beyond the healthcare facility, temperatures were lowered throughout the network. This innovative approach effectively avoided the need to operate the entire site at higher temperatures, resulting in significant reductions in heat losses.

Close collaboration was established with equipment suppliers to understand best practices and optimise system performance. Contractors selected for the project received initial training and underwent regular witnessing and quality assurance checks by FairHeat’s Operation team, ensuring alignment with the project’s specifications.

To minimise disruption for residents, FairHeat scheduled works during warm periods in the summer of 2022, providing ample notice to residents. They also coordinated closely with the hospital facility to ensure an uninterrupted hot water supply during the works.

Throughout the Mildmay project, FairHeat collaborated with stakeholders, including the client, supply chain contractors, and AGA (a construction safety specialist), ensuring the safe and successful delivery of the works. This comprehensive approach sets a benchmark for effective project management and stakeholder engagement.

The Mildmay project has delivered a Heat network we can all be proud of. Residents have reliable heating and hot water service and we have made significant savings in electricity, water and gas. The current financial and energy crises had made these works invaluable to our residents. – Daniel Perager, Head of Heat, Energy and Water, Notting Hill Genesis


The Mildmay project has achieved remarkable success and delivered innovative solutions with impressive results, notably through a significant reduction in gas consumption. A comparison of gas meter data from June to December of 2021 and 2022 revealed an outstanding 39% reduction, equivalent to 422MWh, and a decrease of over 88.6 tonnes of CO2 emissions in a 6-month period. This reduction has not only led to cost savings for residents but has also contributed to lower carbon emissions, aligning with sustainability goals and addressing climate change concerns.

The positive impact of the gas consumption reduction extends beyond financial and environmental aspects. Residents now benefit from lower energy bills, improving affordability and enhancing their standard of living. Furthermore, the project’s success in reducing carbon emissions contributes to global efforts in mitigating climate change effects.

Another notable achievement of the Mildmay project is the repeatability of the techniques employed. The majority of the works focused on two Heat Interface Unit (HIU) models, demonstrating the potential for replicating the implemented strategies in similar projects. This offers the opportunity for wider adoption and impact in the future, amplifying the project’s significance.

Additionally, the project resulted in a substantial removal of equipment from the site, leading to a significant reduction in electricity consumption. This not only enhances energy efficiency but also simplifies the maintenance strategy and reduces ongoing upkeep resources.

As an exemplary project that has benefitted from the HNES Demonstrator, FairHeat and NHG organised and hosted a full day site visit for the Department of Energy Security and Net Zero’s (DESNZ) heat network team. As a result, the Mildamay project is being referenced in several public documentations.

Tom Naughton, Associate and Head of Operation at FairHeat comments:

Tackling climate change means improving our existing building stock. This isn’t a job for one person or one company – it’s a team effort that needs operators, consultants, and contractors to work closely together. In this respect, we’ve been incredibly fortunate to work with Notting Hill Genesis. Their commitment and energy have been essential to our mission and have led to substantial energy savings.

To actually see the improvement in the reliability and performance of the heat network over the duration of the project was fantastic. And most importantly, the impact it had on the residents living there, through reduced heating bills and a more reliable system.

Working with Notting Hill Genesis has been a genuine pleasure. Their commitment and partnership have been vital in our efforts to reduce the environmental impact of their buildings.

The project achieved a remarkable 39% reduction in gas consumption, equivalent to 422 MWh, between June and December 2022 compared to the same period in 2021. This led to substantial cost savings for both the client and residents, enhancing the affordability of energy and showcasing the project’s financial viability and long-term benefits.

The project resulted in a decrease of over 88.6 tonnes of CO2 emissions in a 6-month period. This significant reduction in carbon emissions aligns with the UK’s NetZero carbon and sustainability goals for 2030, demonstrating FairHeat’s commitment to mitigating the effects of climate change and promoting a greener future.

FairHeat employed innovative strategies, including tailored solutions for different Heat Interface Unit (HIU) types, performance-focused targets, and optimized temperature management within the network. This fresh and forward-thinking approach not only improved the effectiveness of heat networks but also served as a valuable model for future similar projects.


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