Green Building: A lesson in Waste Management

The 5ha industrial site at East Tamaki is getting dressed up for a Green Star rating.

A tired industrial site in Auckland's East Tamaki that housed an old bottling plant has found a new lease of life after Waste Management New Zealand put its full commitment towards sustainability.

Waste Management, a nationwide waste collection and recycling company, signed a 25-year lease agreement with the owner Stride Property and pushed for the $50 million plus site redevelopment in East Tamaki Rd to have a 5 Green Star rating.

Publicly-listed Stride embraced the proposal, and the rating assessment by the New Zealand Green Building Council is taking place right now. The 5-hectare site is targeting a 50 per cent reduction in greenhouse gas emissions.

More than 300 staff have moved into Waste Management's centralised modern head office, which includes an amenities block, workshops and truck and bin storage, after combining other facilities spread around Auckland. There is no transfer station on site.

Jasmax designed the 3000sq m office building. Eclipse Architecture designed the other industrial facilities. Hayden Rollet completed the construction, and engineering consultant Cosgroves provided the building services and sustainability advice.

David Haylock, Cosgroves' associate and engineering leader (mechanical), said one of the biggest advantages of the project was that the developer and Waste Management acted as a single client, and created an integrated design process from the very start to make the best use of the site.

"It was a long-term project and there was a lot of investment at stake to do it right.

"Waste Management's directive was 'we can do better', and the developer saw the value in making its property sustainable.

"The project is a good example for others. When you are talking with a client about sustainability and green buildings, they always ask 'will it work and where else has it been done'.

"Waste Management was over the moon with the final outcome — they came away from pretty average facilities to a decent product," he said.

"There was nothing revolutionary about we did on the site — it was all good practice and improving minimum standards.

"It just takes a little more care during the design stage and a client who is willing to go down the sustainable path.

The new head office has brought 300 of Waste Management's staff together and improved their wellbeing.

"More people seeing these types of projects will result in more sustainability taking place," said Haylock, who is speaking on the Stride/Waste Management project at the Green Property Summit in Auckland today, hosted by Property Council New Zealand in conjunction with the NZ Green Building Council.

Cosgroves played a strong hand in developing a state-of-the-art stormwater system and electric vehicle charging facilities, as well as the building services.

The stormwater system was designed to reduce peak flow and contaminants from the site, and therefore have less impact on the environment. This was achieved by providing over-sized pipes for drainage in conjunction with a detention tank, as well as using swales and Stormwater 360 filters to treat the stormwater run-off before leaving the site.

Storage tanks collect 150,000 litres of rainwater from all of the main roofs, and this water is used for toilet flushing and truck and bin washing to reduce the demand on the city's main water supply.

The combination of efficient (tap and shower) fixtures and the rainwater collection reduces the domestic water consumption of the site by nearly 90 per cent.

Haylock said it was hard to incorporate a large amount of green space on the site due to the operational constraints but "we managed to do it around the office to improve stormwater run-off and reduce reflected heat from the pavement.

"Incorporating the swales was challenging because it required careful co-ordination with the infrastructure serving the electric vehicle charging and the site."

Cosgroves established three swales around the staff car parking to slow the stormwater run-off.
The swales are broad, shallow hollows covered in grass and plants. Over time the plants improve the water quality.

The engineering consultant installed electric vehicle charging facilities for 40 cars and 14 trucks — Waste Management is in the process of converting its entire fleet, cars used by sales staff and rubbish collection trucks, to electric.

Haylock said the site incorporates a management system that monitors the load of the switchboard supplying the electric vehicle charges.

The system adjusts the charge rate to ensure peak demands don't exceed the capacity of the infrastructure.

"This ensures the charging facilities can be provided without the need for drastically over-sizing the infrastructure to cope with the rare occasions when the electric vehicle charging coincides with peak building demand.

"There is also inground ductwork to allow for the charging to be expanded to more than 100 light vehicles and 50 trucks," he said.

The Waste Management office and amenities block are energy efficient. The office building's facade incorporates high performance double glazing to reduce solar gains and heat losses. The building has concrete sandwich panels with insulation between the two outer layers.

This allows the mass of the internal layer of concrete to act as a heat sink, passively regulating the building temperature as it changes over the day and night, reducing energy consumption.

The ventilation uses heat recovery from the exhaust air of the spaces. For the office, a thermal wheel helps dry the moist Auckland air in summer as it enters the building, transferring its latent heat back to the exhaust air stream.

The amenities block has a large outdoor air load due to the exhaust from the toilets and showers, and a run-around coil heat exchanger is used to keep the supply air and exhaust air streams separate.
Haylock said the heat system recovers up to 70 per cent of the energy from the exhaust air from the office and amenities block which again reduces energy consumption.

High performance LED lighting was installed with a focus of providing good light levels only where required, as well as light on the surfaces (walls and ceilings) to improve the overall perception of the lighting in the space.

This minimised the lighting power density, and was coupled with an advanced automatic control system that utilises occupancy and automatic daylight dimming.

The control system further reduces the energy consumption of the light by 25-40 per cent.

Haylock said the Waste Management site is going through the second stage of the Green Star assessment. "It has been a challenging project. It was decided that the whole site should be assessed, not just the office building, and we all had to try a lot harder to make everything compliant.

"I think the project has done really well. You can't fake it with the assessor. He makes his assessment based on the documents provided and you can't communicate with him."

Haylock said the advantage of having a 5 Green Star is that the developer gets a higher-value property; the tenant gets a better product and nicer place to work in; the energy bills are less; and from the council and public's point of view the buildings have less impact on the environment around them.