Softly, softly

Building services expert Martin McLaughlin explains how the Government Soft Landings process was invaluable for the University of East London’s new, award-winning library.

At its heart, Government Soft Landings (GSL) is all about getting things right at the start of a construction project. By asking key questions up front — about how a completed building would be used, and who would be working there, when and for how long — and then reviewing the project against these objectives regularly, GSL makes the path from design, through construction and into occupancy smooth.

Although GSL will be mandatory for all projects procured through government departments from 2016, some have already started to adopt the approach, such as University of East London’s (UEL) new library building on its Stratford campus.

AECOM was the building services consultant on the library project for UEL, which was designed by Hopkins Architects. Sustainability criteria were tough. Annual energy use targets of 100kWh/m2 for both regulated and unregulated energy consumption were pretty exacting for a building open 24/7. GSL is helping UEL and AECOM work towards achieving these targets.

Open all hours

Having investigated how students used the campus’s existing library facilities, AECOM knew that people would need to get in and study at all hours of the day or night. It was found that usage was significantly less at night however, which led AECOM to implement a demand-led system for key systems such as ventilation and lighting, enabling sections of the services infrastructure to be switched on and off as needed. Photovoltaics on the roof and a raft of power-saving IT measures also helped keep consumption to a minimum.

UEL’s facilities team played a key role in the specification of these critical systems, working closely with design teams as part of the soft landings pre-construction review to assess options. A life cycle costing analysis was crucial and enabled teams to balance flexibility, energy consumption, and implementation and maintenance costs.

Better than L

Heating and insulation was efficient too. Every element of the building’s fabric was designed to be more energy efficient than the minimum standards demanded by Part L (the energy efficiency requirements of the Building Regulations). Thermal mass provided by the building’s exposed concrete soffits and reinforced concrete frame helped to minimise internal temperature fluctuations, absorbing heat during the day and releasing it back to the space at night. In winter, two gas-fired condensing boilers provide heating for when temperatures dropped below minus 1°C.

A GSL engineer was engaged during construction, and prior to commissioning to witness development of the library’s controls and metering strategy. The engineer worked closely with the subcontractors and project specialists to lead the client training sessions ensuring that, on handover, the UEL team was familiar with the building’s engineering systems.

Checking up before checking out

Following the new library’s handover, a post-completion GSL monitoring programme was established to help fine tune the systems and achieve the university’s energy targets. For the first six weeks after opening, engineers were based on site one or two days a week to optimise the systems in operation. After this, monthly onsite meetings continued to keep an eye on progress.

The presence of both engineers and the design team enabled UEL to adjust the library’s services in response to use and performance. For example, the library’s nighttime occupancy was lower than expected, allowing the operations team to shut down the building’s top floor at night, saving further energy.

Set, point and match

The soft landings team also found that the library’s energy consumption was higher than expected. The team discovered that the CO2 set point in one of the ventilation unit boxes — there are several on each floor as part of the demand-led service — had been adjusted from its original position.

The team is putting in processes to ensure this type of human error does not happen again. For example BMS head-end screens that explain why set points are important, what their operating ranges should be, and the likely impact of adjusting the setting on operational energy use.

So far, so good

So far, the GSL approach seems to be working. When compared to the original design predictions, actual use has delivered major reductions in consumption, including 54 percent less lighting kWh and 63 percent less small power kWh. The server rooms have also consumed 80 percent less energy for both IT and cooling.

There is still work to do. Currently the library’s mechanical systems are consuming more energy than expected — a common operational issue for construction projects, that reflects the difficulty of matching lofty aspirations to the complexities of everyday reality.

This is all within the remit of GSL, however. AECOM and UEL are working together to fine tune the building controls and meet the university’s energy use targets. Once complete, it will make UEL’s new library one of the most energy efficient university buildings in the UK.