Across the UK, mixed-use developments are becoming a defining feature of the built environment.
From large-scale regeneration schemes to smaller urban infill projects, the combination of residential, office, retail and leisure space is reshaping how buildings are designed, delivered and operated.
Mixed use is now a key element of regeneration programmes around the UK. National and local governments view mixed-use developments as a pragmatic response to several urban challenges because they support efficient land use, provide homes and create local employment opportunities.
They also often enhance the public realm with parks and areas for social interaction.
Developers are also drawn to mixed use schemes by the resilience that comes from diversifying income streams across different asset types.
The real advantage lies in thinking about energy at a district or campus level
Mike Egan Business Development Manager
Complexity and opportunity
Colliers ‘Mixed Use 2.0’ report underlines this adaptability, noting that flexibility in design and the ability to shift between functions are now central characteristics of successful mixed-use schemes.
For building services engineers and designers, this convergence of uses creates both complexity and opportunity.
Different building types have very different heating and cooling profiles. Residential demand typically peaks in the morning and evening, while offices and retail spaces are driven by daytime occupancy.
Leisure uses, such as gyms or cinemas, may have entirely different load patterns again.
Traditionally, these would be treated as separate systems, each designed to meet peak demand within its own building.
However, the real advantage of mixed-use schemes lies in the ability to think about energy at a district or campus level rather than building-by-building.
When multiple uses are brought together, their differing demand profiles can be balanced, with energy shared and reused across the development.
Low temperature heat networks
This is where low-temperature heat networks, known as ‘fifth generation’ or ambient loop systems, come into their own.
Rather than relying on a centralised heat source distributing high-temperature water, these systems operate at much lower temperatures and allow individual buildings to draw heat from – or reject heat into – a shared loop.
This changes the role of HVAC within a development. Instead of simply generating and distributing heat, systems are designed to manage and balance energy flows. Waste heat from one part of the scheme can become a valuable resource for another.
For example, heat rejected from cooling systems in retail units or gyms can be captured and used to support domestic hot water or space heating in nearby residential buildings.
In practical terms, this is where technologies such as water-source VRF systems can play a role, enabling simultaneous heating and cooling and supporting heat recovery across different parts of a development. In effect, the scheme becomes an energy ecosystem, where supply and demand are continuously aligned.
Significant benefits
The benefits of this approach are significant. Lower operating temperatures reduce distribution losses and improve the efficiency of heat pumps, which are central to low-carbon heating strategies.
Solutions such as air and water source heat pumps can be deployed at building level to connect into these wider networks, providing flexible, scalable heating and hot water across residential and commercial spaces.
At the same time, heat reuse reduces overall energy consumption and lowers carbon emissions.
For developers and operators, this can translate into reduced running costs and improved sustainability credentials, supporting compliance with increasingly stringent regulations and net zero targets.
However, realising these benefits depends on decisions made early in the design process.
Mixed-use developments are inherently complex, with multiple stakeholders, phased delivery programmes and evolving design requirements. If energy systems are considered too late, opportunities for integration can be lost.
Early intervention
By contrast, incorporating low-temperature heat networks and shared energy strategies at the master planning stage allows the infrastructure to be designed around the needs of the whole development.
This includes sizing plant appropriately, planning distribution routes, and ensuring that buildings are configured to connect effectively to the network. Flexible system architectures, including modular heat pump solutions and adaptable VRF systems, can support this phased approach as schemes evolve over time.
This early-stage thinking also aligns with the broader trend towards flexibility in mixed-use schemes. As the Colliers report highlights, developers are increasingly adapting the balance of functions within projects, often shifting from office to residential or introducing new uses as market conditions change.
A well-designed energy network can accommodate these changes, providing a level of futureproofing that standalone systems cannot. As buildings evolve, the network can continue to balance loads and optimise performance across the development.
Lower GWP VRF
This creates a growing demand for solutions that can operate effectively within these shared, low-temperature environments. Technologies such as advanced VRF systems using lower GWP refrigerants like R32 offer a pathway to improved energy and carbon performance, particularly in commercial spaces within mixed-use schemes.
Combined with intelligent controls and building management systems, these solutions allow operators to monitor and optimise performance across multiple buildings and uses, ensuring that the full benefits of an integrated approach are realised.
Mixed-use developments are often described as the future of urban living, but from an HVAC perspective they are also an opportunity to rethink how energy is generated, distributed and used.
By moving beyond a building-by-building approach and embracing shared, low-carbon systems, developers can unlock efficiencies that are simply not available in single-use schemes. The result is not only better-performing buildings, but more sustainable and resilient places.
A partner with experience across both individual building systems and wider energy strategies can make a significant difference in delivering these outcomes. Mitsubishi Electric’s portfolio spans air and water source heat pumps, advanced R32 VRF systems and controls that support integrated, low-temperature network design, giving project teams the flexibility to respond to different uses within a scheme while maintaining overall system efficiency.
By working closely with designers and developers from the early stages, it is possible to create HVAC solutions that not only meet the needs of each building but also contribute to the performance of the development.
Mike Egan is Business Development Manager
