The Zenith building.

22 May 2014 — The investment DEXUS has made in upgrading the sustainability of its commercial portfolio is showing bottom-line results, with blue chip tenant Lend Lease joining the NSW Government, Commonwealth of Australia and Wilson Parking in leasing space at its Zenith building in Chatswood, Sydney.

The property, managed and half-owned by DEXUS (GPT Wholesale Office Fund owns the remaining 50 per cent), is one of 25 commercial office properties that has had energy efficiency improved, giving DEXUS overall a stronger, more profitable and future-proofed offering.

Upgrades were carried out on Zenith’s building services over a two-year period from 2011-2012 to improve the building’s energy and water usage performance and gain an improved NABERS rating. The initial 3 star NABERS rating has now risen to 5.5 star NABERS Energy and Water rating. Overall, the upgrade program at Zenith reduced energy costs by 40 per cent and water costs by 25 per cent.

The Zenith archway at night.

Specific measures addressed the building’s mechanical systems, building management control systems and lighting systems. Works included upgrading existing chillers, fitting of variable speed drives on chilled and condenser water pumps and car park air supply fans, replacing cooling towers, upgrading the heating water system and rebalancing and retuning the air and water systems.

The building management system was replaced, and all control systems and routines upgraded for airconditioning and ventilation. Motion detector lighting controls were also installed throughout.

A comprehensive metering system was installed, and detailed trend-logging capability enabled, which allows staff and service providers to quickly identify building performance issues and take action to ensure there is no impact on the NABERS rating. Building services staff can access this information from their computer or smartphone and carry out daily reviews of performance.

DEXUS rolling out portfolio-wide upgrades

The Zenith upgrade is part of a three-year upgrade program across the entire DEXUS office portfolio.

The $31.1 million works program, which was partially funded by a $3.5 million grant from the Australian Government’s Green Building Fund, has seen the average NABERS energy rating across all DEXUS office properties rise from 3.2 stars to 4.7 stars in 2013, when the program was also recognised for excellence with a Green Globe Award in the Built Environment Sustainability category.

The latest NABERS assessment has seen further improvement, with a current office portfolio NABERS Energy rating of 4.8 stars on a like-for-like basis for the quarter ended 31 March 2014. The increase in efficiency was achieved through a focus on control and feedback solutions to optimise building operation.

In planning how to proceed with each specific upgrade, a careful analysis was undertaken of which plant to retain and which to replace, factoring in aspects such as lifecycle considerations, payback period, specific property strategy and contribution to achieving the target star rating.

The Zenith entry.

For DEXUS, the benefits of the program include higher levels of tenant satisfaction, lower occupancy costs, reduced energy costs, higher property values, increased tenant appeal and energy cost savings for tenants.

The program has also future proofed the portfolio, and aligns the properties with the company’s integrated corporate responsibility and sustainability strategy.

To ensure tenant behaviour does not compromise a property’s NABERS rating, DEXUS ensures leases incorporate provisions to utilise best endeavours for both the landlord and tenant to collaboratively optimise base building and tenancy resource consumption.

The tenant information pack that is issued to new tenants provides a description of key energy and water-based systems including airconditioning, control systems and lighting. These descriptions highlight the designed performance criteria and its disclosure ensures DEXUS and its tenants are aware of performance parameters that are intended to maintain NABERS Energy and Water ratings.

“Experience has shown that upgrades to services and plant modernisation benefit tenants by improving comfort conditions and amenity, reducing maintenance costs and improving the buildings’ NABERS rating,” David Yates, DEXUS executive general manager, investor relations, marketing and communications said.

“These factors result in higher levels of tenant satisfaction, contribute to retaining tenants and improve property valuations.

“DEXUS is committed to providing tenants across its portfolio with efficient and sustainable leasing options. Performance data collated by IPD continues to demonstrate that ‘green’ buildings continue to outperform the broader office market across a range of financial indicators.”