Hartman-Cox Architects is committed to sustainable practices and in particular the limitation of greenhouse gas emissions in three ways:

- designing buildings only in urban communities,
- preserving the embodied energy of existing buildings,
- designing energy efficient buildings.

Urban Infill and Campus Environments
For more than 30 years, Hartman-Cox Architects' buildings have been constructed entirely in urban and campus environments (ie, zero Greenfield sites). These are areas that have available utility infrastructure and redevelop our communities. Commuting time and emissions are reduced, no trees or agricultural land is destroyed, and public transportation is readily available.

Preservation and Adaptive Reuse
Over half the work at Hartman-Cox Architects involves some component of preserving existing structures and/or adaptive reuse. These buildings contain "embodied energy", a significant amount of energy of all types required to construct the building initially. Retaining this energy by reusing the building means that that energy is saved, as is the energy required for demolition of the building if it were to be destroyed.

Energy Efficiency
Investigating energy conscious design and planning is a matter of course for Hartman–Cox Architects. Developing new strategies, energy modeling and life cycle cost analyses that consider initial cost, energy, life span/replacement, and maintenance are fundamental to our practice. Site orientation, building envelope design, day–lighting, creative lighting and controls, and efficient mechanical systems are intuitive and constantly interwoven.

Leadership in Energy and Environmental Design
While our primary goal at Hartman-Cox Architects is to reduce greenhouse gas emissions, we produce economical and sustainable buildings in many other ways; the LEED rating process, as established by the US Green Building Council, provides a framework for measurement and verification of sustainability. Over the last two years, over half of our projects have received certified LEED Silver or Gold status. Currently, the Denver Judicial Center Detention Center and New Law School Academic Building at the University of Michigan – School of Law are on track for LEED Silver certification. The American Pharmacists Association Building in Washington DC and 1515 Wynkoop in lower downtown Denver are both certified LEED Gold. Although not all of our clients pursue formal certification, all of our projects meet LEED criteria. One third of our architectural staff are LEED Accredited Professionals with extensive experience on multiple sustainable projects.

Sustainability in the Studio
The studio environment at Hartman-Cox Architects is supportive of our mission to design sustainably. Two thirds of the employees use alternative means of transportation for commuting (metro, bus, walking, biking). Our office is in an early 19th century warehouse in Georgetown (embodied energy/ adaptive reuse), there is bicycle parking in the building and a shower facility. We use non-disposable dishware and have a full recycling program, high efficiency lighting with dimming controls, programmable thermostats and low flow fixtures.