Invo purchased a building shell which wasn't as "green" or as "greenfields" as the company would have liked but it ticked all the other boxes.
"Security-wise we looked at all the potential weaknesses and devised defences," Pettengell says. "Roller doors are usually the weak point as they buckle and collapse easily and we needed to stop something about the size of a medium truck driving or reversing into the door at up to 30km/h. The gate that became the solution weighs 2000kg and the locking pins hold 50 tonnes of shear force each. The electronics and safety features to run the gate made up half the $70,000 of eventual cost. This gate like all the building's electronic security systems are wired into the main security control system and are operated from wall mounted touch pads or over the wide area network where possible."
Other security features include high tensile steel grills, smoke cloaks and disorienting strobe lights.
The building exterior also has a number of long range cameras that capture activity in the surrounding area and some high resolution internal cameras.
Pettengell says that on the "eco or low energy side" he wanted to run the building off solar panels. "But bolting panels to the roof is putting the cart before the horse. First the building had to be designed with low energy devices and systems to get consumption as low as possible and then size a solar system.
"We got it so low that 39 185w panels were enough for everything including a three phase forklift. We could actually push power into the grid during the day and draw it back as required at night or on dark days."
Check meters at the distribution board show where the power is being used or over used, and sensors prevent power wastage. The air conditioning system is also controlled similarly.
Building insulation was doubled where possible, between internal walls and floors.
"Our own extrapolations indicated that we needed about half the air con plant that would traditionally be required for this type of environment," Pettengell says. "However, during our search for installers, we were laughed at and told that the council would never grant compliance. As it turned out, the units run at a little less than half capacity."
The power supplied to the wall sockets and the lighting systems are split into essential and non-essential. When the security system is armed and no one is in the building, non-essential circuits are turned off by a relay at the switchboard. However, essential power circuits stay alive 24/7 for devices that must remain on at all times like refrigerators, fax machines, servers, security and solar water heater controllers.
Pettengell says the building's dimmable lighting was "experimental" with no contractor having installed such a system in this type of building before.
"The lights are on lux sensors that brighten or dim the lights based on the light coming in from outside. For over eight months of the year the warehouse lights are dimmed to zero as the light levels exceed 300 lux. But when dark clouds reduce the available ambient light, the lights power-up to compensate."
The system was helped by painting the walls a gloss white and the floor a light grey so light would be reflected as much as possible. There are only three light switches in the entire building.
Pettengell says the biggest challenge in relation to the project had nothing to do with the systems or materials - it was the attitude of the Auckland building industry.
"I got sick of hearing, 'you can't do that', 'that's never been done before', 'it won't be compliant', 'we are required to install to this specification', 'it will invalidate warranty', 'that's gonna cost a fortune', and on and on. The Auckland trade was unwilling to learn new skills, apply new ideas and technologies to a point where some even obstructed progress. I always told them it would be at my risk and expense but even with this indemnity they couldn't get their heads around it."
Pettengell says he was lucky enough to have Jack Barber from Jack Construction in Wellington as the project manager/builder. "He wasn't afraid to try new ideas, solve problems differently and he made it his job to get inside my head and understand the objectives. As phases of the project began to fall further behind, we fired some of the local contractors, and flew up trades people from Wellington who completed their work without the daily hassles that had plagued the job and with the skill of the project manager, got the job completed on time."
