Pro Tips and Case Studies on Multifamily Energy Efficiency

In early April, Lorax Partnerships co-presented “Pro Tips and Case Studies on Multifamily Energy Efficiency” with Baumann Consulting at the 2018 Montgomery County Energy Summit. Co-hosted by Montgomery County Department of Environmental Protection (DEP) and U.S. Green Building Council-National Capital Region (USGBC-NCR), the Montgomery County Energy Summit is focused on commercial energy efficiency and clean energy in the County. The audience for this event is geared towards Montgomery County building owners, property managers, energy contractors working in the County, young professionals in the energy field, and people who are interested in sustainable commercial buildings.

In tackling the questions of energy efficiency in multifamily residential buildings, Lorax had four main learning objectives to tackle throughout the presentation:

  1. Understand the implications of the new Montgomery County Green Construction Code on multifamily residential and illustrate the major energy consuming systems development typical for multifamily residential buildings in Montgomery County.
  2. Identify design principles, new technologies, and processes that contribute to energy efficient multifamily housing, and describe common energy conservation measures and thermal comfort improvements to multifamily residential buildings including air sealing and insulation, lighting technologies and controls, variable capacity compressors, modern system controls, variable frequency drives and engagement with occupants.
  3. Discuss the strategy that was successful for the Westbridge Condominium board to reduce energy consumption and the opportunity for replication to other multifamily residential buildings.
  4. Identify an implementable plan for advancing regional benchmarking for compliance to wide scale deep energy retrofits among multifamily residential buildings.

The Presentation

Over 18% of the US population live in multifamily residential buildings, which consume over $18 billion in annual energy costs. Average energy use intensity (EUI) across the multifamily housing stock is an unimpressive 78 kBTU/sf/yr, yet new high-performance building design can readily achieve an EUI between 20 and 30 kBTU/sf/yr and retrofits of existing buildings can lower EUI by 30% or more. These energy savings opportunities represent billions of dollars in avoided costs for both Owners and Tenants, along with significant positive environmental impact.

While deep energy savings may conjure thoughts of major capital expense, design challenges and construction hurdles, there are simple and effective steps to pull it off without inducing a headache. The benefits are numerous – lower utility bills for tenants, improved occupant comfort, higher tenant retention rates, increased opportunities for financing and incentives, fewer operations and maintenance pitfalls, and reduced building life cycle costs. The initial portion of our panel will focus on best-practice and cutting-edge strategies for energy reduction among major energy end-uses of multifamily residential through the design and construction process: HVAC, water heating, appliances, and lighting.

In addressing post occupancy energy efficiency, a detailed case study of the Westbridge Condominiums shows how required benchmarking can lead to energy improvements. After three years of benchmarking and meetings with the condo board, the energy consultant conducted an investment-grade energy audit. Specific projects that followed included upgrading LED lights and controls in May 2016, replacing a 40 year-old water-side heat exchanger and redesign of a water-cooled condensing unit and air-handling unit with a variable capacity packaged unit in December 2017.

Incentives from the DC Sustainable Energy Utility and regular and in-person communication of data-driven recommendations between the energy consultant and the condo Board triggered the energy saving actions.

 

In the presentation we drew on advice from an energy expert, a green building adviser, a developer, a property manager and a mechanical engineer, sharing real-world case studies to highlight how these strategies have been successfully implemented in the Mid-Atlantic market.