Why Small Steps Can Help Us Tackle a Big Goal
By Patrick Kunze, President
As jurisdictional deadlines approach and cities announce goals for Zero Carbon 2030 or Net Zero Energy (NZE) by 2030, our partners from the building industry remain concerned: how are we going to reach these aggressive goals in the next nine years? At GHT Limited, our experience suggests that while DC building owners and developers are interested in going Net Zero (particularly Net Zero Energy), the design strategies required to achieve “a zero energy building which produces enough renewable energy to meet its own annual energy consumption requirements” remains financially out of reach. Architecture, engineering, and multi-discipline firms across the globe eagerly joined the 2030 Challenge, which aimed for 80% fossil fuel reduction by 2020, 90% by 2025 and Carbon Neutral by 2030. But the office marketplace, particularly in the Washington, DC Metropolitan Area, has lagged in constructing buildings which meet these goals, with Build-to-Suit and Educational organizations (Higher Ed and K-12) leading the charge in delivering Net Zero facilities.
In the wake of the COVID-19 pandemic which disrupted global supply chains and our national economy, our highest priority is designing resilient, high-performing buildings which decrease reliance on fossil fuels, while contributing to our nation’s increasing demand for renewable energy. The time for Net Zero is NOW – yet many in our industry (including those who fund and develop buildings) still find that NZE is out of reach.
Achieving NZE across all buildings will take big steps, but there are smaller actions we can take today to move the needle.
- Start with the Building Envelope: While HVAC systems generate ~50% of a building’s energy, the exterior envelope of the building has a tremendous role in energy usage, and it is the first area to consider when going Net Zero. The DC region’s climate adds another hurdle, with temperatures and humidity widely fluctuating between seasons. A high-performing building should include a robust skin to keep the outsides out – consider triple-pane glazing, phase change insulation, solar strategies which shade the building and light shelves/solar tubes to bounce light into interior spaces while offsetting heating loads. Utilize your engineering team effectively! Build an energy model early in design and run simulations based on energy use – try to get as close as possible to ZERO by comparing the estimated energy consumption to the estimated on-site power generation.
- Consider a Multi-Pronged Mechanical Strategy: With 50% of your building’s energy usage consumed by HVAC systems, an integrative process with early integration of your MEP engineer and energy modeler to your design team is essential. Know that innovative solutions, like sorbent-based air cleaning, can reduce demands on conditioning outside air. Geothermal systems can use the Earth as a heat sink – harnessing the power of our planet to reject heat to the ground during the summer and draw heat from it during the winter to naturally regulate building temperature. Wastewater heat recovery systems are another design strategy which work better for urban projects and DC Water supports this strategy, which utilizes heat and energy from the sewer system and helps the building collect or reject heat through an exchanger system. Lastly, consider a Dedicated Outdoor Air System (DOAS) or liquid desiccant system. DOAS separates ventilation and dehumidification, moves energy through liquid (which is more efficient) and reduces airflow to only what is needed. Liquid desiccant systems dry humid air using less energy, which saves on cooling costs while allowing warmer temperatures inside the building without loss of occupant comfort.
- Know That Users Will Need to Make Concessions: Now that you’ve taken steps to reduce energy usage through smart envelope design and selecting the right systems, it’s time to face the facts – adding in building occupants consumes energy and certain user sacrifices are required to go NZE. The silver lining is that lighting systems are more efficient than ever, and light tubes can be used to pull daylight deep into buildings without added heat load. Tenant requirements need to be clearly defined and integrated into building leases and education is paramount to success – occupants may not be permitted to charge their phones at workstations, laptops are preferred over energy-hogging CPU’s and data centers are relocated off-site or to the cloud. Elevators should also be used sparingly, so aesthetically pleasing design of communicating stairs is always the right call. Photovoltaic panels, or solar generation, can help offset loads but rooftop space is limited in DC so this isn’t a viable one-stop-shop to achieving NZE. More good news? The fastest growing workforce groups (Gen X, Millennials and Gen Z) have listed sustainability, resiliency and a company’s response to climate change as some of their top priorities in the workplace.
- Understand NZE is the Long Play: It will be difficult to revolutionize the building industry towards NZE without substantial incentives (and penalties). There is a reason every building hasn’t already gone NZE – it is both difficult and costly. Net Zero Energy won’t make sense for everyone, but it is up to us and our peers to educate owners about the long-term benefits and payoff that result from this initial investment. It’s also imperative that we recognize and reward the incremental steps building owners take to get there, through tax rebates and incentive programs.
Design, location, user needs, and budget can dictate whether Net Zero Energy is a possibility for your building – but when it comes to creating a NZE building, the most important step you can take is approaching the design with a holistic view of energy systems and technologies.
This is at the core of the GHT approach: Net Zero is the goal we start from – not what we work backwards to. By utilizing an integrative design process and engaging your entire team of consultants through the concept phases of design, Net Zero Energy can be a realistic and attainable goal.
Patrick Kunze is the President of GHT Limited, an award-winning mechanical, electrical and plumbing (MEP) engineering firm in the Washington DC region for more than five decades. He is a senior mechanical engineer with 20+ years’ experience designing high-performance spaces for clients such as the United States Green Building Council, the American Society of Interior Designers and Fortune 100 companies.