Transgrid's HQ at 180 Thomas St, Haymarket, Sydney.

TransGrid’s new Haymarket HQ in Sydney has become the first NSW project to be awarded a 6 Star Green Star Office Interiors v1.1 rating in round one of assessment, exceeding its original sustainability targets at no extra cost thanks to initiatives from the project team, client and subcontractors.

The building has also been awarded 5 Star Green Star Office Design V3 and 5 Star Green Star Office As Built V3 ratings, and recently won the contractor, Built, a NSW Master Builders Association Award for Excellence in Resource Efficiency for  its dematerialised fitout and high waste recycling rate.

The design for the nine-storey commercial office building by Bates Smart, Enstruct and Arup was the winning entry in a City of Sydney design excellence competition. The building is situated above an existing four-storey building, and an innovative use of heavy steel trusses across the roof of the existing building to act as a giant transfer truss enabled the new structure to cantilever six metres out beyond the envelope of the existing building, giving an extra 300 square metres of floorplate for each level.

Philip Vivian

Director of Bates Smart Philip Vivian said the practice was able to create open-plan flexible grid floorplates for the new building by shifting the lifts from a central core to an external glazed lift shaft. The structure also uses lightweight structural steel, and this made it possible to add an extra floor, using the existing building’s footings.

A major gain for Green Star credits came from the absence of excavation, retention of the existing building and that there was no need for further piling.

Bates Smart worked in collaboration with the two engineering firms, following an integrated design approach. Enstruct supplied the structural engineering expertise, and Arup provided the services, ESD, vertical transportation, acoustic, facade and fire engineering.

“This project needed a full team,” Mr Vivian said.

He said Bates Smart always worked closely with engineers on designs from the initial conceptual stages, and as a “humanist practice” designed buildings that were “people places”.

Spaces that enable people to communicate and collaborate have been proven to lead to better results for a business, and from the employees point of view, were the best type of place to work in, he said.

Transgrid occupies three floors of the building, and an integrated fitout was undertaken by Built to the Bates Smart team’s design for the 4400 square metre workspace.

The office features a two-storey wintergarden on the northern elevation with hydronic in-slab heating and mixed-mode ventilation comprising operable louvres for natural ventilation and active chilled beam airconditioning supplying 100 per cent fresh air.

Timber from old telegraph poles

Mr Vivian said one of the team’s major gains in the design was threading the active chilled beam system through the structural beams throughout the building.

The wintergarden also incorporates vertical greening with plants including ivy specifically chosen for their beneficial effect on indoor air quality. Mr Vivian said the use of plants continues throughout the entire office space.

A three-level atrium void in the centre of the floorplates with an intertenancy stairway brings high levels of natural light and also contributes to the connectivity between floors.

The pre-cast concrete passive solar shading elements on the facade, which reduce glare and thermal load, were designed to be an integral part of the building’s aesthetic.

“The building has an interesting orientation at 45 degrees to north, so you can have either horizontal or vertical shading. We played with this and gave some of each to each floor, and randomly stacked them like boxes,” Mr Vivian says.

“The solar shading becomes the expression of the building.”

The third facade typology is sheer glazing comprising double-glazed integrated glazing units with motorised blinds behind them.

The entire facade is designed for disassembly at end-of-life so the elements can be recycled or re-used.

Being located close to Central Station and public transport, and a design that integrated cycling facilities, meant the project attained points for low-carbon transport. Mr Vivian said it also allowed the team to reduce the carparking allocation.

He said the fitout materials were chosen for their environmental credentials, with the designers paying close attention to supply chains. Some of the suppliers specified have buy-back arrangements as part of end-of-life product stewardship.

“We’re researching what our suppliers tell us, and we preference accredited suppliers,” Vivian says.

Getting the extra Green Star points at no extra cost

Originally the team were tasked with achieving a 5 Star Green Star Interiors rating, however it was some of the subcontractor decisions and some of the client’s own decisions that took the project over the line to 6 Star.

Joe Karten

Built senior project engineer quality and sustainability Joe Karten said the extra points were acquired both in the original project pathway, and through the detailed furniture, fixtures and equipment specification, and were all achieved at no extra cost above budget.

Largely, it was a matter of the team identifying items that would achieve extra points, “going back to the calculator” and working closely with the Green Star submission consultant, Belinda Konopka from Surface Design Consulting.

“The [International Standards Organisation] standards applicable to [environmental product declarations] recognised within the Innovation Challenge include ISO 14025 and ISO 14040,” Mr Karten said.

The challenge requires eight per cent or greater of fitout value be comprised of products with an ISO-certified EPDs. Products used that contributed to this percentage also included Interface Continuum Carpet, Desso Palatino Tile, Arper Catifa 53 chairs and Knoll/Formway Be Chairs.

Also, the ceilings and partitions subcontractor used Knauf products that came with an EPD. Mr Karten said many of the subcontractors had the appropriate product paperwork to meet Green Star requirements, such as low-VOC certification for paints and sealants. This, he said, is a reflection of the extent to which subcontracting trades are themselves taking up the environmental sustainability ethos.

Prior to working for Built, Mr Karten worked with the Green Building Council of Australia for four years. During this time, he said he occasionally did project walk throughs with clients who would comment that the “green stuff” was “mumbo jumbo”. In response he would say, “Do you smell that?”, and they’d say “No”, to which he’d reply, “That’s the point”, explaining that low-VOC paints means no “new paint smell”, which also means better indoor air quality, and less risk of health issues including asthma.

Dematerialisation

Dematerialised fitout – exposed services and polished concrete

One of the distinctive features of the fitout design is what’s not there – in the common circulation areas, the services have been left exposed rather than ceiling tiles or other extra finishes added, and the floors are a polished concrete rather than carpet. This “dematerialisation” reduced waste and also reduced the footprint of the fitout.

TransGrid’s own initiative to specify ergonomic chairs also included undertaking an ergonomic study and the engagement of an ergonomic consultant to work with staff to optimise workstation configuration and deliver training on looking after their health in the workplace.

Instructions have also been produced for how to optimise wellbeing and ergonomics for the use of future employees.

Mr Vivian said this was a reflection of the client’s own agenda in relation to its staff.

“It is an obvious concern for any employer of choice… how to look after its workforce. It’s about, how can we look after our staff and make sure people want to stay? Good employers are very conscious of staff,” he said.

“It’s highly inefficient to get new staff all the time.”

The ergonomics initiative also scored the project an extra Innovation Challenge point.

“I was always aware that billing for additional points was on Built, but this was something [the client was] already doing,” Mr Karten said.

Recycles telegraph poles

The fitout features extensive use of timber, including the secure wall that separates reception from the working spaces. All of the joinery was created by H Dallas Industries from recycled telegraph poles, which Mr Karten said was a fitting source given the nature of TransGrid’s business.

Greater than 50 per cent of the common use costs in fitout was cabling cost.

“Most of this was Nexans Olex, a [best environmental practice] PVC cabling product. In total, approximately 10 per cent of overall common use PVC products were PVC-alternatives, with 90 per cent made up by best practice certified PVC,” Mr Karten said.

Rainwater is being harvested and reticulated for amenities, and waterless urinals have been installed throughout.

The entire project was delivered with recycling rate of over 96 per cent for both base building construction and fitout waste.

Mr Karten said metals were sorted out on site for on-selling to metal recyclers, and the rest of the waste was put in commingled skips and sent to Bingo for processing. The majority of non-recyclable components comprised insulation off-cuts, polystyrene and sheet plastics.

“The MBA award for Excellence in Resource Efficiency on TransGrid’s fitout recognises a shift in values and demonstrates that ‘less’ is indeed ‘more’,” Mr Karten said.

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