Party Walls


Paula is the Director of Sustainable Building Services at SWA. She specializes in professional architecture and design, with particular expertise in high performance design within the commercial and residential sectors. Paula has assisted dozens of commercial and residential projects in successfully achieving building certification, securing government incentives, and exceeding energy code compliance. In addition, Paula is currently a member of the USGBC LEED Energy & Atmosphere Technical Advisory Committee - allowing her to discuss the challenges of LEED and energy efficiency in new construction buildings, as well as discuss future plans of the rating system.

Posts by Paula Zimin

Low-Carbon Concrete: Reducing the Embodied Energy of a Notorious Emitter

It is safe to say we are in a climate crisis. Of the last 17 years, 16 have been the hottest on record.[1] Sea level is expected to rise by as much as eight feet by the end of the century.[2] And by 2050, as many as 140 million people will have been displaced by climate change.[3] The time to act is now, and a major area of impact is buildings, which account for 40% of carbon emissions in the United States. Better envelopes, lighting, and mechanical systems are helping buildings become more efficient, which means an increasing proportion of carbon—up to 68% of a building’s lifetime emissions—is locked up in materials.[4] This “embodied” carbon gets released during a material’s extraction, manufacture, transport, maintenance, and, eventually, disposal.

If our industry is to meet the 2030 Challenge of carbon neutrality by the close of the decade, we will need to reevaluate building materials and select low-carbon alternatives.

Embodied carbon life-cycle

Figure 1: Courtesy of Faithful+Gould


LEED v4.1 O+M is All-In!

Are you in? The US Green Building Council (USGBC) wants you to be. The “All-in” campaign has just officially expanded to include the new and highly anticipated LEED v4.1 for Building Operations and Maintenance (O+M).

Full disclosure: As a member of the Energy and Atmosphere (EA) Technical Advisory Group, I was involved in reviewing LEED v4.1 modifications. In the past, LEED had set significant barriers to entry for existing buildings. For example, LEED O+M EA Prerequisite Minimum Energy Performance set a baseline ENERGY STAR score of 75, which restricted certification to the top 25% of efficient buildings. This limitation often caused building owners to abandon LEED before even getting started, thus eliminating a key incentive for improving underperforming buildings’ environmental impact. LEED 4.1 has fixed this problem. The restrictive prerequisite for energy performance has been replaced with a voluntary credit, encouraging building owners to benchmark energy use and screen capital improvements against energy impacts.

The newest version of LEED O+M also incorporates Arc, USGBC’s performance tracking platform. In Version 4.1, the energy score is calculated based on two energy metrics:

  1. LEED v4 ImageThe traditional ENERGY STAR metric of annual Source Energy Use Intensity (kBtu/sf);
  2. The Arc metric of Annual Greenhouse Gas Emissions Intensity (GHG/person).