Net Zero Buildings place #79 on Drawdown’s list of climate solutions, capable of sequestering 7.1 gigatons of carbon by 2050 if only 9.7% of new buildings hit the standard. Net zero designs, which enable a structure to generate as much energy as it consumes over the course of a year, integrate multiple energy solutions, so Drawdown calculates their impact as a single system.
“The building industry has the potential to have a large impact on drawing down greenhouse gas emissions,” Drawdown says. “There are many different energy efficiency strategies to reduce the impact of buildings.” And “onsite energy generation takes buildings a step further to reduce their impacts.”
The summary includes two varieties of structures in the net zero category. Net zero buildings produce the energy they need to operate through the use of onsite renewables, drawing no resources from utility-scale sources. Net zero carbon buildings, meanwhile, generate no carbon emissions over the course of the year, but some use carbon offsetting to meet the target.
Some of the solutions integrated into net zero buildings include improved insulation, glazed windows and electrochromic glass, energy-efficient lighting and water heating systems, better heating, ventilating, and air conditioning (HVAC) systems, and distributed renewable systems that create energy close to where it’s used.
The latest designs also incorporate rainwater capture and onsite sewage processing.
The summary points to examples like the Rocky Mountain Institute Innovation Center, a 15,600-square-foot (1,450-square-metre) building in Basalt, Colorado that was built to withstand the severe cold of the region. Designers focused on keeping people warm, rather than trying to heat the entire space. In addition to planning systems that addressed air temperature and wind movement, they looked at other factors that could affect human comfort, like the kinds of clothes people wear and their activity levels in the space. Designing with these ends in mind, they were able to forego conventional air conditioning and rely on a small heating system during periods of extreme cold.
In addition to an R-67 roof with a photovoltaic solar panel system, the structure uses less water than the annual rain- and snowfall volume, and is home to a greywater system that will go online as soon as state regulations catch up with the technology, Drawdown says.
With the cost of net zero building systems continuing to decline, Drawdown forecasts a continued uptick in their adoption world-wide.
“Net zero buildings were once a novelty, but are becoming more commonplace as architects roll out extraordinary buildings across the world,” the summary states. “There is now a Walgreens drugstore in Chicago that is a net zero building. Net zero neighbourhoods, districts, and communities are also being designed and constructed.”
A bonus benefit: because net zero buildings are built to be self-sustaining, they’re reliable in blackouts and natural disasters, climate-related or otherwise, when grid-connected homes and workplaces face much more serious jeopardy.