Site Lines: A home fit for the future

HLM Architects is raising its profile in the residential sector with a design concept showcased in a major Government design initiative to create ‘age-friendly’ and sustainable housing. Matthew Thomas explains more

Last year HLM Architects’ ‘Forever Home’ concept was one of six finalists for the RIBA-run Home of 2030 competition. This sought to find homes that are ‘age-friendly’ as well as having low environmental impact, supporting healthy living, and able to be delivered at a large scale to solve our housing shortage.

The competition was announced by Housing Minister Christopher Pincher in June 2020, and was based on four themes, including ‘age-friendly and inclusive living,’ ‘low environmental impact,’ ‘healthy living,’ and ‘deliverable and scalable.’

All entries are required to reflect the Government’s published response to the Future Homes Standard consultation, where new homes are expected to achieve a 31% reduction in carbon emissions from 2021.

To achieve these bold ambitions, HLM partnered with sustainability experts Daryl Fisher from sustainable building consultancy HLM Greenbuild, and Dan Beynon from multi-disciplinary engineering practice Hydrock. The team was augmented by the Advanced Manufacturing Research Centre in Sheffield, and Mid Group, a cutting-edge offsite contractor.

The design proposals that emerged envisioned flexible, affordable, and sustainable ‘forever’ homes, providing great places to live and work. They support the development of stable communities where people can invest in their homes, which are able to expand and contract with the life changes of those who live in them. This approach promotes putting down roots in a place, developing social and community coherence.

Furthermore, the ‘forever home’ concept stimulates a circular economy through the use of modularised systems that enable homes to be adapted, with construction components able to be sold back into the ecosystem of supply chain parts for re-use.

This means that homeowners can realise the value in their homes without ever moving – meaning the costs associated with moving house several times can be invested in the quality of the home instead.

The concept is particularly beneficial to housebuilders and developers as it enables them to select contractors and suppliers from a much wider pool. As well as making the tendering more competitive, it also serves to safeguard the supply chain ‘ecosystem’ by ensuring there is also a backup manufacturer or supplier should one become incapable.

As well as focusing on the building itself, the design proposals considered how homes and their owners/occupiers can develop stronger communities. Dense terraces with development space ‘baked-in’ to the proposals mean that space can be created for community use. It facilitates the creation of community building at the heart of the neighbourhood, by providing green space and by encouraging walking and cycling ‘by design,’ facilitating active streets and social interaction. As the world shifts towards more agile working, the ability to work from home or work in a flexible community workspace reduces the need for long commutes, therefore reducing carbon released from transport.

Fabric & tech
Reducing carbon emissions associated with homes while maintaining comfort and low running costs demands a focus on efficiency. HLM’s ‘forever home’ focuses on a fabric first approach with excellent U-values for floors, walls and roofs, high quality triple-glazed windows, minimising thermal bridging and targeting airtightness rates that achieve Passivhaus standards.

To support excellent indoor air quality and minimise heat loss from the home, a highly efficient mechanical ventilation with heat recovery (MVHR) unit has been adopted, recovering approximately 90% of the heat from extracted air to heat the fresh supply air.

These key approaches are supplemented by ‘gentle engineering’; air source heat pumps providing hot water and space heating that, when coupled to low temperature underfloor heating, allows the heat pump to operate at optimum efficiency. Flexibility within the manifold system also allows for additional rooms to be easily ‘plugged-in’ to the system as the home evolves with its owner.

Photovoltaic (PV) panels on each dwelling’s roof provide what little energy is required to these super-efficient homes, reducing carbon and running costs for the homeowner. The PV area is calculated to balance the operational energy and carbon of the home with the option for homeowners to install additional PVs to generate electricity for an electric vehicle, for storage in batteries to balance demand spikes, or to sell as part of a ‘micro grid.’

The design solution achieved ensures that systems are user friendly and easy to control. These simple controls can optionally be enhanced through smart home technology utilising sensors and controls to monitor temperature, humidity and CO2; adjusting heating, ventilation and lighting to optimise user comfort and wellbeing, and minimise energy usage.

Care was paid to the carbon embodied in the materials proposed. It is important to understand how materials are produced, where they are produced, how they are transported and ultimately, how they are recycled or disposed of. To reduce embodied carbon to its lowest level we must focus on locally sourced natural materials wherever possible. The ‘forever home’ has been designed to allow the specification of materials, components and products which are designed to be recycled or reused; natural; low in embodied carbon, locally sourced, and/or high in recycled content.

Combining these strategies and modelling the performance of the ‘forever home’, HLM have determined that the kgCO2e/m² achieved could be as little as 212. This far outstrips the RIBA 2030 target of 300.

The lifespan of these new homes will be far beyond that of your typical house – bringing a truly sustainable forever home closer to realisation.

Matthew Thomas is an associate at HLM Architects