Extreme weather events like the 2019 polar vortex and the catastrophic hurricanes from 2017 are a significant investment risk for real estate developers. A well-designed structure can withstand these events, but key building services are often disabled.
For example, strong winds can damage power lines and cause extended blackouts, and flooding can disable equipment in the lower floors of buildings. Under these conditions, a building interior can quickly become unsuitable for human occupancy.
In new construction projects, the design phase provides a great opportunity to make buildings more resilient. For example, important equipment can be installed above the reach of floodwater, and effective insulation can help conserve indoor temperatures when HVAC systems are disabled.
Minimizing the Impact of Floods on Buildings
Buildings normally have important systems in their basements and lower levels, and this equipment provides services for the entire property. Consider the following examples:
- Emergency diesel generators
- Chillers and boilers
- Water booster pumps
If this equipment is flooded, the building immediately loses important services: backup power, space heating, air conditioning and the water supply. Indoor conditions quickly become unsuitable for occupants, even if the building itself is not damaged.
Water booster pumps can also be disabled by floods, leaving the upper floors of a building without potable water. An effective solution is having a secondary water supply above the expected flooding level. Ideally, this backup water source should be at an elevation that can be reached by the supply pressure, to make it independent from pumping. Consider that the power supply for a pump may be unavailable during extreme weather.
How an Efficient Building Envelope Improves Resilience
Effective insulation and air tightness offer savings all year long, reducing the workload on both heating and cooling equipment. However, an efficient building envelope also improves resilience, since it helps conserve a suitable indoor temperature during emergencies.
Having plenty of openable windows also contributes to building resilience, since lack of ventilation can quickly degrade air quality. Given that mechanical ventilation is disabled during blackouts, having natural ventilation as an option is recommended. If openable windows are limited, air pollution levels will gradually increase during an extended blackout, with no effective access to fresh air.
Backup generators and water supplies can be placed above the reach of floodwater to ensure their availability. Also, a natural gas generator is more reliable because it doesn’t depend on diesel deliveries.
A high-performance building envelope is both an energy efficiency measure and a resilience measure. HVAC engineers can specify equipment for a reduced workload, and indoor conditions can be conserved more effectively during emergencies.
Michael Tobias is the founder and principal of Chicago Engineers, an Inc 5000 Fastest Growing Company in America. He leads a team of 30+ mechanical, electrical, plumbing, and fire protection engineers from the company headquarters in New York City; and has led over 1,000 projects in Chicago, New York, New Jersey, Pennsylvania, Connecticut, Florida, Maryland and California, as well as Singapore and Malaysia.