Denver holds roughly 4,500 commercial properties, and by CDPHE’s own estimates, well over 600 of them cross the 50,000 square foot threshold that triggers Regulation 28 compliance. The city’s building stock skews heavily toward Class A office towers in the central business district, healthcare campuses anchored by UCHealth and Centura Health, large multifamily developments built during the 2015–2023 boom, and industrial/flex properties along the I-70 corridor east of the airport.
For Denver building owners, the December 31, 2026 deadline for buildings 100,000 sq ft and larger isn’t abstract — it’s a firm date with real penalties attached.
Denver Buildings at a Glance
| Data Point | Detail |
|---|---|
| City population | 715,000+ (Denver proper) |
| Metro population | ~2.9 million (Denver-Aurora MSA) |
| Approx. covered buildings (50k+ sq ft) | 600+ commercial properties |
| Major building corridors | Downtown, Cherry Creek, DTC (Denver Tech Center), RiNo/Cole |
| Dominant covered building types | Office, multifamily, healthcare, retail/mixed-use, industrial |
| Local utilities | Xcel Energy (primary), Black Hills Energy (some eastern areas) |
| Key energy incentive programs | Xcel Energy Energy Efficiency Programs, Colorado C-PACE |
Which Denver Buildings Must Comply?
The 50,000 sq ft threshold captures most of Denver’s commercial inventory that matters at scale. Specifically, that includes:
The Downtown and LoDo office towers — everything from the 1670 Broadway complex to the newer Union Station North tower district. Most of these properties are already 200,000+ sq ft and face the tighter December 31, 2026 deadline.
The Denver Tech Center south of downtown, which holds some of Colorado’s densest concentration of corporate office campuses. DTC buildings occupied by tenants like Charles Schwab, Lockheed Martin, and Deloitte are well above the covered threshold.
Healthcare campuses including the Anschutz Medical Campus in Aurora (adjacent Denver metro), the Saint Joseph Hospital complex on the east side, and Swedish Medical Center in Englewood. Medical facilities typically have high energy intensity and benefit significantly from the audit pathway analysis.
Multifamily buildings — particularly the 200+ unit apartment complexes built along the South Platte River corridor, in Five Points, and along the East Colfax redevelopment zone. Multifamily is increasingly common in the 50,000–100,000 sq ft range.
Denver’s Regulation 28 Compliance Timeline
Benchmarking data for Denver buildings is due to CDPHE each year by November 1, using ENERGY STAR Portfolio Manager. The performance compliance deadlines break down as:
- December 31, 2026: Buildings at or above 100,000 sq ft must demonstrate compliance with their selected pathway
- December 31, 2027: Buildings between 50,000–99,999 sq ft reach their first performance compliance date
Starting January 1, 2030, CDPHE can assess fines of up to $2,300 per 30-day period for non-compliant buildings, escalating to $5,800 per period for repeat violations.
Choosing a Compliance Pathway for a Denver Building
Denver’s commercial market has significant variation in energy performance across building types. The right pathway for a 1980s-era LoDo office building differs from the right pathway for a 2021-built multifamily development in RiNo.
In practice, we see four distinct situations in Denver:
High-performing newer buildings (2015+, well-insulated, LED lighting, modern HVAC): Often qualify under Pathway 1 (prescribed EUI target) without any additional investment. An audit confirms this.
Older Class B and C office: Typically need Pathway 2 (EUI reduction from 2021 baseline). These buildings often have retrofitting opportunities — lighting controls, economizer repairs, HVAC replacements — that create real GHG reductions and generate Xcel Energy rebates.
Healthcare and hospitality: High EUI by nature. Pathway 3 or 4 (GHG-intensity targets) may be more achievable given these buildings’ 24-hour operational profiles. We model all four before recommending.
Industrial/warehouse buildings east of Denver: Often already low EUI by building type. Many qualify for the prescribed EUI target without major intervention.
Building Types We Audit in Denver
- Class A, B, and C office buildings throughout downtown, Midtown, and DTC
- Large multifamily residential complexes along the South Platte, RiNo, and Five Points corridors
- Healthcare facilities and medical office buildings on the Anschutz campus and elsewhere
- Retail anchors and mixed-use developments in Cherry Creek, Stapleton/Central Park
- Industrial and flex-space properties along I-70, I-25, and the Montbello/Gateway districts
- Municipal and government buildings managed by the City and County of Denver
- Hotel and hospitality properties in the LoDo and Convention Center district
Xcel Energy Incentives for Denver Buildings
Xcel Energy is the primary utility for most Denver commercial buildings, and it offers commercial energy efficiency incentives that can substantially reduce the cost of improvements identified in your audit.
Xcel’s Commercial Efficiency Programs offer rebates on lighting retrofits, HVAC upgrades, variable frequency drives, building controls, and other measures. Rebates vary by measure type — LED retrofits typically return $0.02–$0.08/kWh saved, while HVAC replacement incentives can run $100–$500/ton of capacity. We identify applicable Xcel rebates as part of every Denver engagement.
For larger capital projects, Colorado C-PACE financing allows property owners to finance improvements through a property assessment — keeping debt off the balance sheet and often achieving cost neutrality before the compliance deadline.
Get Started with a Denver Regulation 28 Audit
The Denver commercial market is large enough that most building owners have time to act methodically — but not so much time that waiting until 2025 is advisable. Audit timelines typically run 6–10 weeks from intake to final report delivery.
Tell us your building’s address and square footage. We’ll send a flat-fee proposal within one business day.
Audit pricing for Denver buildings starts at $6,999 for buildings 50,000–75,000 sq ft. Buildings over 200,000 sq ft receive custom pricing.