CASE STUDY | MASON BROS developed with Precinct Properties. The clients commitment to building tuning played a huge part in its success, along with the project teams adoption of BIM to enable working in an integrated way throughout the project, from design through to asset management, says Calderone (see Digital handover panel on page 23). This collaboration began early in the projects design and has continued into the operation of the building. Through early engagement with the facilities management team, Mott MacDonald was able to understand how the landlord intended to operate the building and was able to adapt its design accordingly, Calderone says. In addition, the project used an independent commissioning agent both pre- and post-system commissioning to further optimise performance. Mott MacDonald continued its collaboration with the buildings facilities team and the commissioning agent after the building was occupied, as part of an 18-month tuning and commissioning programme, following practical POST-OCCUPANCY SURVEY To find out whether Mason Bros was delivering on its strategy to create spaces that are healthier and more productive environments for its clients, a building use study (BUS) was conducted. The BUS is based on a user survey, which included questions on workspace design, access to windows, thermal comfort, air quality, noise, lighting productivity and perceived control. It was carried out approximately 12 months after practical completion. The developer had already carried out a BUS survey on four of its buildings located in Aucklands central business district, none of which were Green Star rated. So in 2018, a BUS was carried out to see how Mason Bros compared against these. The results show: Respondents rated the overall design of Mason Bros very highly. In terms of amenity, access to outdoor spaces rated highly. That the end-of-trip facilities such as bicycle parking, shower facilities, changing rooms and lockers were lower than for the non-Green Star buildings. Interestingly, further investigation found that the building was actually a victim of its own success, and that the facilities were not large enough to cope with a significantly higher number of occupants cycling to work (16%) than had been anticipated, given the Auckland average is 2%. Of the variables measured for heating, ventilation and air-conditioning, the responses in relation to freshness and odour demonstrate the greatest improvement compared to the non-Green Star sample. Mason Bros respondents rated their environment as fresher and less smelly than the non-Green Star sample. This is almost certainly because outdoor air is supplied at a rate at almost 100% more than New Zealand Building Code. Occupants also said they feel more productive working in the spaces at Mason Bros compared with those working in the non-Green Star buildings. Sick leave is reported to have decreased by approximately 20-25% from the two major tenants occupying the building. completion. This ongoing involvement helped to ensure the energy efficient operation of the building services, and has minimised any residual problems to ensure the systems align with the design intent. The commissioning was highly effective: after the first year of operation, the buildings energy use was 57kWh.m-2, representing a 30% improvement on typical best practice, achieving a 5 Star NabersNZ. In its second year of operation, optimisation of the building services operation saw energy consumption reduce further to 48kWh.m-2, a 40% improvement over typical new building performance (assumed as 4.5 Stars under the NabersNZ protocol). The further improvement in energy use saw the building achieve a 5.5 Star NabersNZ rating, making this the highest rated building in Auckland and one of only five 5.5 Star-rated buildings in the country. Andrew Eagles, CEO of the Green Building Council in New Zealand, sums up the scheme: This building isnt just one of the very greenest buildings in Aotearoa [the Mori name for New Zealand] its one of the greenest in the world. And, if further endorsement of the schemes success was needed, both the schemes architect Warren and Mahoney and its engineer Mott MacDonald have moved into Mason Bros. CJ The CIBSE Building Performance Awards 2021 are now open for entries. For details, visit cibse.org/bpa A digital asset information management system developed by Beca allows vital asset information to be accessed via the Cloud directly from iOS devices Post-occupancy research in the Mason Bros property has confirmed the advantages with up to a 25% drop in absenteeism, occupants indicating an increase in their personal productivity of 8.5%, and a massive 130% increase in cycling following the move, says Alain McKinney, senior development manage at Precinct Properties. 24 August 2020 www.cibsejournal.com CIBSE Aug 2020 p20-24 Mason Bros.indd 24 24/07/2020 16:18