In practice: Unite Students’ ‘Gateway’ to an energy-efficiency retrofit

The Challenge

Unite Students provides accommodation for around 50,000 students in more than 140 properties. As part of a portfolio upgrade to help the company reach science-based targets, Unite Students needed to explore new innovations that could help reduce energy use, heating costs and water consumption.

As is often the case, there is no one size fits all to sustainability and very few innovations are available that would prove universally applicable across Unite Students’ portfolio. However, a lifecycle refurbishment programme at the Sidney Webb House near Borough Market provided a small window of opportunity to implement energy-saving technologies in a cost-effective manner.

With a small team having to operate in a three-month retrofit window, Unite Students realised that leaning on the knowledge, expertise and data of other companies could assist with a speedy rollout of measures.

The Solution

In January 2017, Unite Students joined the Innovation Gateway, and alliance of companies that collaborate to examine methods and technologies that can reduce the costs and environmental impacts of operations and buildings.

Unite Students was already working on a series of heating and lighting upgrades across other buildings in its portfolio. But after joining the Innovation Gateway the halls of resident at Sidney Webb House would act as the first building to be fitted with technologies identified through the Innovation Gateway.

So far, the Innovation Gateway alliance has sourced more than 640 building-related innovations for its partners, with RBS estimating annual operational savings of £7.5m, 200,000m3 of water and 40,000 tonnes of CO2 as a result.

As part of the retrofit which saw new kitchens and bedrooms fitted in each apartment, Unite Students also fitted the building with Mitsubishi Q-Ton Air Source Heat Pumps and Prefect Heating Controls, while also utilising its past experience with dual-flush toilets, water-saving taps and showers and LED lighting. In fact, Unite Students is close to completing a £21m LED lighting and controls upgrade – one of the few technologies that could be deployed across the entire portfolio.

Unite Students had also been examining the Mitsubishi Q-Ton Air Source Heat Pumps prior to joining the Innovation Gateway. After working with the Gateway’s partners, Unite Students fitted eight of the heat pumps – after trials at a Bristol accommodation confirmed their viability – and the Prefect Heating Controls, which automatically turns off heating in unoccupied rooms.

The Benefits

Sidney Webb House was once criticised over certain living condition aspects, but has since been retrofitted into a modern student accommodation.

As the new energy and heating systems have only been in place for less than two months, little data is available regarding costs and efficiency improvements. However, Unite Student trials show that the heating control with the PIR reduces heating-related consumption by around 200 kWh per bed per year. For Sidney Webb, it is anticipated that at a property level that would be 90,000 kWh per year.

The heat pumps are expected to reduce hot water energy consumption significantly, with Unite Students claiming that savings could potentially reach 60%.

Before the LEDs were installed, lighting was accountable for about 20% of the building’s load. It is expected that these levels will be halved following the retrofit. In some instances, the savings from the LEDs will be minimal – such as ensuite bathrooms – but in others, such as Landlord corridors, consumption can be reduced by up to 90%.

Unite Students involvement in the Innovation Gateway will also provide benefits for the energy and environment team. Both group energy and environment manager James Tiernan and technical solutions manager Gareth Chaplin noted that the Gateway enabled them to improve the process of finding the best solutions for Unite Student buildings. It also meant they could spend less time looking for potential solutions, as a diverse pool of tested technologies was now open to them.

The Future

Unite Students is currently working with the Science-Based Targets Initiative to finalise its carbon reduction goals, but the energy efficiency of its building’s will act as an integral factor regardless.

As well as evaluating its building portfolio under ESOS assessments – a process which identified around £150m in lifetime savings that could be achieved through energy efficiency measures – Unite Students is also exploring numerous other technologies.

Networked heating, hot water controls, onsite renewable energy, dynamic demand side management (DSM), battery storage, building services controls and optimisation, and building fabric improvements have all been outlined as potential and current projects.

As for the Sidney Webb House, United Students will monitor the performance of the embedded technologies, feeding data back to the Innovation Gateway so that others can benefit from the findings.

Unite Students is also looking at retrofitting numerous other buildings and will use the data sourced from Sidney Webb House to discuss what solutions, if any, would be viable, notably for the heat pump retrofit.

Matt Mace