One Year On: How The Denver Green Roof Law Affected Commercial Construction

With the third-worst urban heat island effect in the U.S., Denver certainly needed to do something about heat absorption. Other issues were also going to be affected by the Denver Green Roof Law, first approved by popular vote in Fall 2017. One year later, how has the Denver Green Roof Law affected commercial construction, and where is the law at now? Let’s take a look.

To talk with an expert about your next commercial construction project, get in touch with our team at i2 Construction.

Denver Green Roof Law History

After passing the law in Fall 2017, the Denver Green Roof Law took effect on Jan. 1, 2018, requiring new buildings of 25,000 square feet or larger to have a green roof. Only a percentage of the roof needed to be “green”, or have vegetative space. At 25,000 square feet, 20% of the roof needed to be green space, and the percentage would jump every so often, topping out at 60% for 200,000 square foot building or larger.

This law would only apply to new roofs – new construction, or roofs replaced at their normal interval.

The goal of the Denver Green Roof Law was to reduce stormwater runoff, reduce the urban heat island effect, reduce energy costs, improve air quality, reduce noise pollution, extend roof life, and beautify the city.

Green roof laws already exist in San Francisco and Toronto. Chicago and Washington D.C. have green roof incentives in place.

Adjusted Denver Green Roof Law

In 2018, discussions began on how to implement the new law. The Denver city council created a task force to make recommendations on how to adjust the law to best work with the developers and builders.

Eventually, the Denver Green Roof Law became more of a “cool roof” law, allowing light-colored, reflective roofs or green roofs on the same size buildings. Builders can also pay a fee to have equivalent green space installed elsewhere or install other renewable energy sources.

Moving forward, builders and re-roofers will have a few different options for their roofs on buildings greater than 25,000 square feet, rather than just a green roof.