'Living rooftops' could be required in Denver, if Initiative makes it to ballot and passes

DENVER -- You could call it a mile high makeover of sorts.

A grass roots group is attempting to get an initiative on the November ballot that would require every building of a certain size to offer rooftop gardens.

The environmentally-minded group called The Denver Green Roof Initiative is hoping for ‘living rooftops’ on all new construction and existing buildings over 25,000 square feet.

"There's so many good things, and so few drawbacks," said Brandon Rietheimer, founder of The Denver Green Roof Initiative. "They clean our air and sequester carbon. They increase a building's energy efficiency by lowering temperatures of the building."

Rooftop gardens also reduce what is called the urban heat island effect, wherein concrete and buildings make the temperature about five degrees hotter in downtown than other parts of the city.

Rietheimer says Denver has the third-highest urban heat island effect in the nation, behind only Albuquerque, New Mexico and Las Vegas, Nevada.

“When we have a higher heat island, we actually have more energy usage for cooling," Rietheimer said.

The Colorado Apartment Association agrees that green roofs reduce heat island effect and lower energy costs, but the CAA has big reservations about the mandate in the intiative.

Rocky Sundling, incoming president of the CAA, gave the following statement:

"The Colorado Apartment Association and the commercial real estate industry in general agree that green roofs (or living roofs as they are sometimes called) are a great solution to the urban heat island effect, are an effective roof insulator, and are aesthetically pleasing.  We strongly disagree with mandating the installation of these green roofs, even with sensible exemptions.  These roofs are costly to install and to maintain.  Denver is already experiencing an affordability problem in residential and commercial real estate, so let’s not make this affordability problem worse with costly mandates.  Allow the market to work and let buildings that choose to install green roofs experience the competitive advantage that these roofs will likely provide.  Other buildings will follow to maintain competitive equality.  We have seen this voluntary building standard work very effectively with the LEED energy certifications.  We believe the green roofs program will have similar success by allowing the market to demand their installation."

Rietheimer argues the costs will pay off in the long run.

"They do last four times as long as your traditional roof," he said.

The initiative also requires that building owners maintain the rooftop gardens.

Maintenance of the rooftop gardens would be required under this initiative, much like a building code inspector looks for proper bathroom ventilation and working smoke detectors.

"To make sure that they are being repaired from hail damage, from any kind of drought," Rietheimer said.

Rietheimer says the rooftop gardens aren’t a big attractant for rodents, but they do attract bugs and birds.

“This type of garden essentially creates a natural habitat that would have existed if this building hadn't been there,” he said.

There are also special exemptions written into the initiative.

"If a building wouldn't be able to handle the weight of a green roof and snow load, then they would be able to get an exemption for a smaller green roof or a smaller green and solar roof," Rietheimer said.

The grass roots group must now collect the 4,700 signatures required to get the measure on the November ballot. The deadline is this August.