Updates To The Denver Green Roof Initiative Explained!

green roof

Green As Far As The Eye Can See

Imagine you are in a hot-air balloon, slowly taking off in the middle of a city’s downtown sector. You see the normal aspects of city life: hurried pedestrians, bright lights, and cars screeching at one another. Heat rises from the black asphalt.

You continue to gain height. Plants peek from windows, leaves hang off balconies. Suddenly, upon reaching the rooftops, the city explodes with biodiversity. The rooftops are carpeted in greenery and blooming with flowers. Bees and butterflies swoop from one building to the next. Solar panels bask in the sunlight.

This is the vision that accompanies Denver’s Green Roof Ordinance, passed in November 2017. The goal of the ordinance is to reduce the urban heat island effect in the city, as Denver is the 3rd worst heat island in the nation.

The ordinance requires that every building in Denver larger than 25,000 square feet must dedicate a certain percentage of its roof to solar panels or greenery. A green roof is an added structure on top of a normal roof, where vegetation grows. The percentage depends on the overall size of the building and the number of floors the building contains. The bill, passed in November 2017, was one of the most comprehensive in the nation. It requires the creation of green roofs on both new and existing buildings.

Yet putting this ordinance in place is not a simple task. The Denver Green Roof Ordinance is an example how difficult implementing  environmental policy can be. Although a green skyline seems idyllic, it can cause many problems on the for those of us not currently floating away in a hot air balloon. The initiative was not perfect; for example, when passed in November, ordinance required green roofs retain a certain amount of water. This requirement violates Denver fire code. Additionally, many existing roofs in Denver are not strong enough to support a green roof.

A City Divided

Before the election, the ordinance was hotly debated: real estate experts argued the ordinance would raise real estate prices, construction costs, and could increase rents for tenants. This is possible; in Washington D.C., where a similar ordinance has been passed, buildings with green roofs collect 7.4% more in rent. (This number could be influenced by the fact that buildings with green roofs in Washington D.C. tend to be newer.)

Proponents of the Green Roof ordinance have replied that long-term costs of green roofs ultimately would save money. According to the United States General Services Administration, a properly built green roof more than doubles a roof’s lifespan. This is because vegetation and soil reduce the base roof’s exposure to UV light, weather, and mechanical damage. A green roof can also aid with building insulation, helping reduce costs of heating and cooling. In the summer, a green roof reduces heat transfer by 72%.

To ensure that the ordinance properly considers unintended consequences of the bill, the City of Denver has formed the Green Roof Task Force. Katrina Managan, Energy Efficient Lead of the Green Roof Task Force and member of the Department of Public Health and Environment, said the Task Force’s “overall goal is to honor the four benefits of the ordinance while adding flexibility and reducing costs.” These priorities are improvements of green space, reduction of Denver’s heat island, greenhouse gas emission, and water/stormwater management.

“I’ve been pleased with the stakeholder’s group. The city employers have done due diligence calculating impacts,” says Ean Thomas Tafoya, deputy campaign manager of the Green Roof Initiative. Even though Managan said the Task Force will not be focusing on air quality improvement, Tafoya believes the Task Force will sufficiently accomplish the original goals of the ordinance. “Many of these goals–improvement of green space, reduction of coal burning–compliment concerns over air quality,” he explains.

The Task Force have recently released their proposal for approval from the City Council. Their plan incorporates concerns from over ninety public comments, many from developers and business owners. The Task Force must work fast;  some developers are waiting to hear about the finalized requirements before they begin new construction projects.

Through their process, the Task Force has changed the green roof requirement. After hearing complaints from business owners who felt one-story buildings were disproportionately affected, the Task Force suggested the amount of green roof or solar roof required should be determined by the size of the building times the number of floors.

The One Size Fits All Approach Was Never Going To Work

The new proposed ordinance requires all roofs, both existing and new, to be made of cool roof material. The only exception is if the roof is a character-defining architectural feature. According to Managan, “cool roof and green roof have the same benefit when combating a heat island; but, the green roof was going to cover only part of a roof, while the cool roof will to cover an entire roof.” The revised bill also requires buildings to pick one of eight options for a greener Denver. This includes green roofs, financial contribution to an off-site green space, solar energy, 12% increased building efficiency, LEED Gold level certification, or Enterprise Green Communities certification.

This flexibility reflects the diversity of both building structure and public comments over the Green Roof Initiative. The combination of a cool roof and plus another green option could make the city even more environmentally friendly than the original ordinance.

The option to contribute financially to a green space raises one concern: how can our city be improved if the dedicated green space is located off-site? Tafoya responds that, although he hopes these green spaces would be located as close as possible, this is still a helpful option. “Denver doesn’t have a direct funding source for its parks. We often don’t have the revenue to purchase land for park space. For example, Loretto Heights (a park in Denver) got sold to a big developer. If we put this money into a fund to allow for land purchase, I’m okay with that.”

The new Green Roof Ordinance Proposal may not create a plant utopia above Denver. But Denverites will see new green spaces from all heights: on the ground, on porches, and on roofs.

This bill has the opportunity to prove that even complicated environmental policy can work. Through its many environmentally-friendly options, it exemplifies how we must utilize dozens of tactics to create a greener future.

For more information on the original ordinance or to keep up with any proposed changes, please visit the City and County of Denver’s website or the Denver Green Roof Initiative website.

Green Roof Gardens by Plant Escape

We want to help you beautify your roof and expand your living space while keeping expenses down through “Container Gardening on Rooftops,” an alternative to green roof gardens. Traditional installation of green roof gardens involves substrate layers of roofing and irrigation materials, costing 2-3 times the cost of a non-green roof. Plant Escape Container Roof Gardens cost a fraction of traditional green roof installation, include an self-contained irrigation system while meeting all the requirements of the Colorado Green Roof Initiative 300 Building Code.

Our Process

At Plant Escape, we begin the Green Roof Container Garden installation with a consultation, determining your design and plant preferences; and how you’d like to personal your space with art, pathways, water features, living walls, etc.  Then we design your Roof Top Garden within your budget and present it to you for approval. Our installation team is scheduled for a 1-2-day installation process and are available to maintain it thought out the year.

Get a Free Estimate

Plant Escape is a professional plant design company specializing in a variety of plantscaping and landscaping services. As one of the few green roof garden designers in Denver, we are the best company to design and install a green roof garden for your location. You can count on us for quality service and design every time. Contact us today for a free consultation and estimate at 720.586.4960.

Sources:

https://www.bizjournals.com/denver/news/2018/06/25/green-roof-changes-move-forward-at-city-council.html

https://www.alcc.com/denver-green-roof-task-force-makes-final-recommendations

 

Leave a Comment