Brandon Rietheimer, the campaign manager for Denver Green Roof Initiative, stands in the rooftop garden at the Ralph L. Carr Colorado Judicial Center on March 3, 2017. Rietheimer’s campaign persuaded voters in November 2017 that Denver should require all new buildings of 25,000 square feet or larger to devote a portion of the roof to gardens and other green coverings that would absorb rainfall and reduce heat.
Starting Monday, it’s official: Denver will have the nation’s most stringent, far-reaching mandate for rooftop gardens — a requirement that will affect both the developers of larger new buildings and the owners of many existing structures when they undergo roof replacements.
But that doesn’t mean the dust has settled from the Denver Green Roof Initiative’s approval Nov. 7 by 54.3 percent of voters, or that the new law won’t change.
The building industry still is working to understand how plans and budgets will be affected by the new requirements — which generally apply to structures with at least 25,000 square feet of gross floor area underneath the roof. Site-plan filings for new development projects show evidence of a small, late-December rush of submissions to the Denver planning department in an attempt to beat the green roof ordinance’s Jan. 1 effective date, but the large surge expected by some observers didn’t materialize.
And starting in May, when a six-month prohibition of any meddling with voter initiatives expires, the City Council can, with a two-thirds majority, make changes to the detailed new ordinance. But council members have insisted they won’t seek to repeal it outright.
Anticipating the need for some tweaks, the Denver Department of Public Health and Environment already is forming a review task force that includes initiative backers, opponents, representatives from Denver Water and Xcel Energy, and building and green-roof experts.
The initiative’s backers were motivated by the goal of reducing Denver’s urban “heat island” effect from heat-radiating roofs, but several issues could come up in the discussion.
Among those are costs for developers, use of the fees that will be charged for buildings that get variances, watering requirements in Denver’s semi-arid climate, whether the initiative is complicated by Colorado water rights laws and how it will affect large developments planned by the city — including as part of a $937 million bond package that also won voter approval last month.
So far, the task force doesn’t worry the initiative’s proponents.
Initiated Ordinance 300 campaign manager Brandon Rietheimer says some clarifications likely will be necessary in the first months since the initiative, in drawing opposition from Mayor Michael Hancock and much of the city’s business community, was crafted entirely by the grassroots activists.
Rietheimer and the initiative’s technical adviser, Jennifer Bousselot, both said they had seen a good-faith effort by the Hancock administration to implement the measure.
“I think they’re taking it very, very seriously — exactly what the voters wanted,” said Bousselot, a special assistant professor in Colorado State University’s horticulture department. “I’m really impressed.”
Denver’s new rules, which allow the use of solar panels to offset some rooftop garden coverage requirements, will exceed those set out by green-roof pioneers San Francisco and Toronto. Those cities apply green-roof requirements to new buildings, but not to roof replacements on existing buildings that meet size thresholds, as Denver’s new law does.
The replacement provision is causing some of the greatest consternation in the real-estate industry, as is the potential impact on large industrial and warehouse buildings.
Bill Mosher, the senior managing director of the Trammell Crow Company, a Denver commercial and industrial developer that has incorporated rooftop gardens into some projects, said he was glad the initiative intensified discussion of the city’s green policies. But he questioned whether rooftop gardens were the best strategy and expressed concern about the new ordinance’s effect on buildings that have large footprints, owing to rules requiring larger green-roof areas.
“I don’t think it impacts high-density downtown areas nearly as much as it will affect suburban low-rise, two- and three-story office buildings,” Mosher said.
Supporters of the new law point out that green-roof technology isn’t new and has been used successfully on new and retrofit projects of varying kinds. For new roofs, estimates range between $25 and $35 a square foot, with the prospect of energy-use savings as an offset.
Zeppelin Development installed a rooftop garden and solar panels on its Flight office building in fall 2017 the River North Art District and Globeville.
City attorneys reject request to delay ordinance
This month, the city attorney’s office rejected a request from the Colorado Real Estate Alliance, which coordinated the opposition campaign, to delay the effective date by six months so that varying concerns could be sorted out.
The alliance’s letter said the Jan. 1 date posed “too significant a risk” and gave insufficient time “to safely and strategically implement the ordinance.” But assistant city attorney Kirsten Crawford replied Dec. 13 that a delay in implementation would violate the city charter’s prohibition of any changes to the ordinance in the first six months.
Alliance chair Kathie Barstnar said last week that developers with potential projects in the works are waiting for more clarity on the rules. She, as well as Rietheimer and Bousselot, are planning to fill spots on the review task force.
“They’re going to be bringing together the groups that, in our opinion, should have been brought together to develop the ordinance in the first place,” Barstnar said.
On Tuesday, the city released 14 pages of proposed rules and regulations that provide more detail on how city planners will apply the green-roof rules. A public hearing on those rules is set before the Denver Planning Board on Jan. 17.
Rietheimer and Bousselot say they plan to lodge some concerns with those draft regulations — particularly some that would allow more wiggle room than intended for roof replacements on existing buildings when a green-roof retrofit requires major structural alterations. Some quibbles, for rules on building additions, are based on city lawyers’ literal readings of the ordinance that Rietheimer says don’t reflect their intent.
At the most basic level, the new ordinance applies to most new buildings of at least 25,000 square feet of gross floor area, as well as to additions that push a building’s size above that threshold. Multifamily residential buildings of up to four stories are exempt.
Green-roof coverage requirements range from 20 to 60 percent of available roof space, depending on the building’s size. Industrial buildings have a different coverage requirement — 10 percent of the roof, up to a maximum of 25,000 square feet.
In all cases, solar energy devices can be used to offset some of the requirements.
A chart provided by Denver’s planning department shows site development plan applications filed, by week, from October through late December of 2016 and 2017. Week 51 is the week of Dec. 25, 2017. The end of 2016 saw a similar bump in applications before development impact fees took effect at the start of 2017.
Denver’s deputy planning director in charge of leading implementation efforts says it’s too early to know how the initiative will affect permitting review times and workloads, which have been strained during the city’s recent development boom.
“We expect this to be a significant change in permitting requirements for contractors, though we’ve tried to work the new standards into our existing processes as seamlessly as possible,” Jill Jennings Golich, of the city’s Department of Community Planning and Development, said in a statement.
“Traditionally, obtaining a roof permit is a simple, online application. Green roofs are more complex,” she said, since existing buildings require a structural assessment before adding rooftop gardens. So, rather than allowing simple online permit applications for affected large buildings’ roof replacements, the department now will require permit reviews, Golich said.
Separate from the review task force, the mayor’s office is seeking members for a Technical Advisory Group that Hancock is charged with forming under the ordinance. It will provide guidance to the city on updating the technical standards spelled out by the initiative.
Rietheimer, the initiative’s campaign manager, says that in the task force’s meetings this winter, he will push for the city to stay true to the initiative’s intent even as it address industry concerns.
“They’ve brought up a lot of really good questions that need to be addressed,” he said. “Ultimately, we want this to be successful. We don’t want it to be a failure.”