Denver’s green roof/green building initiative has changed over time since it was originally passed in 2018. The latest version, known as the Denver Green Building Ordinance, requires Denver property owners with buildings sized 25,000 square feet or larger to comply with one of several green building programs and install a “cool roof”. The ordinance affects all Denver buildings with gross area of 25,000 square feet or larger undergoing a roof replacement, a building renovation pushing square footage over 25,000 square feet, and new commercial buildings over 25,000 square feet.
How Does The City Monitor The Denver Green Building Ordinance?
Denver has a simple way to monitor compliance with its green building ordinance. It works like this: when a commercial roofing permit within city of Denver limits is requested, the building’s square footage must be included in the request. For roof replacements on buildings of 25,000 square feet or more, the next step in the permit process automatically requests input on how the building owner will comply with the Denver green building ordinance and cool roof requirements. The permit cannot proceed without the building owner’s agreement to comply. For professional commercial roofers in Denver, we can assist with this paperwork and documentation.
What Are The Options For Complying With The Denver Green Building Ordinance?
While the original legislation required a vegetative roof, the ordinance has been amended to allow building owners to use one of five options to comply with the Denver green building ordinance. The options are:
Green Space on Roof or Elsewhere on Property
Installing a vegetative roof is still one of the compliance options. An additional option is to install new garden or green space elsewhere on the property if the roof cannot support it. An estimated 87% of Denver commercial buildings would need the structure to be reinforced to support the extreme weight burden vegetative roofs bring.
Onsite Solar Panel Installation
For renovations or re-roofing, installing solar panels that cover 42% of the roof surface (or 5% of gross floor area, or enough to meet 100% of the building’s electricity needs) is an additional compliance option. Similar to the green roof, solar installation can be installed on the roof or elsewhere on the property.
Enrollment in Energy Program
Enrolling in an energy program to commit to reducing your building’s energy usage over a set term is another compliance option for the Denver green building ordinance. With this option, the building owner can select their “baseline” year, and commit to energy reduction (typically 10% usage reduction) over a five-year period. This can be achieved through the installation of a green roof and any of: upgraded HVAC mechanical, wall insulation improvements, new windows and/or doors, and other measures.
Green Building Certification
If your building achieves an approved third-party green building certification, that can also act as your compliance with the Denver green building initiative. Approved certifications include LEED certification, National Green Building Standard, Enterprise Green Community Certification, or approved equivalent.
Fee Payment to Green Building Fund
A final method of compliance with the Denver green building ordinance is a simple fee payment to Denver’s green building fund. This fee is typically assessed at $50 per square foot, but varies in certain cases as defined by the city of Denver.
So what is the best, budget-friendly way to comply with Denver green building ordinance?
The cost in time, energy, and money for each of the five compliance options can vary widely. Simply put, we have observed enrollment in the energy reduction program to be the simplest method of complying with Denver green building ordinance. It allows commercial building owners to choose their building improvements over time to achieve energy usage reduction. It is also estimated to be the most budget-friendly option.
Another popular option is commercial solar panel installation. Solar panel installations are being considered by many property owners anyway, so choosing to time it with a commercial roof replacement project can be a great choice.
Installing a Cool Roof as Part of Denver Green Building Ordinance
In addition to choosing one of the five options above to comply with the Denver green building ordinance, a “cool roof” must be installed in order for the city to approve the project.
So what is a cool roof?
For the most common type of low-slope roof installed on commercial properties, a cool roof means an insulated, reflective roof. Cool roofs must have a minimum reflectivity rating as defined by the roofing material manufacturer, and listed on the commercial roofing permit. They must also be insulated with at least R30 insulation rating if insulation is installed above the structural roof deck (R38 if insulation is beneath the roof deck).
Denver commercial cool roofs must also either have a vapor barrier membrane installed as the first layer of the roofing system, or receive an exception from a licensed building engineer. From what we have noticed, most buildings are able to receive the exception and waive the vapor barrier requirement.
Are there any exceptions to Denver green building ordinance?
Actually, yes. If your building only needs commercial roof repair and not a full replacement, choosing a compliance option is not required. The city defines “repair” as sections of 5% or less of your total roof surface area.
And, if you choose to coat your existing roof instead of replacing the full roofing system, permits and compliance with the Denver green building program are not required. Roof coatings are considered repairs, which are exempt from permit requirements. For many commercial buildings, a professionally installed roof coating can not only avoid the Denver green building ordinance requirements, it can also extend your roof’s life for 20+ years. This can often be meaningful cost savings.
Conclusion
When it comes time to address the roof maintenance for your Denver commercial property, you want a partner that can guide you through the complicated Denver requirements. The permitting, inspection, documentation, and approval process as part of the Denver green building ordinance can be cumbersome. Contact a commercial roofing project manager at Sol Vista Roofing to get started with your project.
