Originally constructed in 1972, the former Castle Boutique Megastore in Phoenix, Arizona, has been transformed from an adult-themed store into the new headquarters of sustainable-building firm DPR. Despite its origins, it would be a mistake to underestimate DPR's new premises, as the building received both LEED-NC Platinum certification and Net-Zero Energy certification from The International Living Future Institute, thus making it currently the largest net zero building in the world.

During its search for new premises in Phoenix, DPR took a look around the former Castle Boutique Megastore and noticed that despite an outside temperature of over 100º F (37º C), the inside of the building was a relatively cool 80º F (26º C).

Recognizing that this indicated excellent insulation, DPR snapped up the 16,533 sq ft (1,535 sq m) building, and set about turning it into not just a sustainable place of business, but a show-office that could be used to demonstrate the best green tech the company could provide.

All required electricity is produced on-site by a 79.6 kW photovoltaic solar panel-covered parking lot, and usage is kept to a minimum with the help of a sophisticated monitoring and control system. Commendably, the building's consumption stats are displayed live online through the website Building Dashboard.

The monitoring and control system also operates 87 windows, opening or closing them automatically to aid ventilation and control temperature. A master cut-off (or "vampire") switch can be thrown come office closing hours to ensure that any errant electrical devices aren't drawing power overnight.

It appears that owing to the local climate and the building's location, water is provided by standard non-renewable sources, though we've reached out to a company representative for clarification on this point.

However, it is the building's passive technology that is of paramount interest here. In order to lower the indoor temperature to a comfortable level without the use of energy-guzzling air-conditioning units, the company used features which are simple in principle, but integrate into the building's monitoring and control system.

When necessary, four "shower tower" evaporative coolers cool the air by drawing it through water mist, before it enters the building. The shower towers draw the air inside with the help of a zinc-clad solar chimney which also expels hot air back outside. To further aid airflow, DPR also installed some active technology: 12 low-energy Isis "Big Ass" ceiling fans.

In order to reduce the need for artificial lighting to almost zero during daylight hours, DPR installed a total of 82 Solatube sun pipes. Sun pipes reflect the sun's rays through pipes in the roof and into the office, providing a bright light inside. Naturally, this system may not be as attractive in a frequently overcast or rainy climate, but it should be perfectly practicable in balmy Phoenix.

In all, DPR's Phoenix headquarters required just under 10 months renovation time and included members of architecture design firm SmithGroupJJR, and global consulting company DNV KEMA Energy and Sustainability. DPR hopes its new premises will prove that suitable older buildings can be modernized to a high degree of sustainability.

"As we continue to push the sustainability envelope, the design decisions we make are so connected to how our buildings perform," explains Mark Roddy, design principal for SmithGroupJJR. "We were able to take a 40-year old building and transform it as a living example for the community and DPR's employees. This project demonstrates that it is possible to live and work sustainably, even in a desert environment."

Source: DPR via Inhabitat