Energy-Positive Buildings Give More Than They Take, Leaving The Planet Better Than Before Construction – CleanTechnica

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Let’s just say it: the building industry is responsible for some 40% of the world’s carbon emissions. That’s enormous! Energy positive through low wattage bulbs? Be serious.

Huge building industry carbon emissions result from many sources: constructing a building, its years of usage, and dismantling after the building has reached its end life.

The carbon footprint of the supply chain for building materials has only recently been intensively scrutinized — it’s more insidious than developers in previous decades had ever realized or revealed. Materials are extracted from the environment and used in a variety of ways that eventually transform the raw resource into a toxic waste product, so that the current global system of material use is linear and exploitive. Cement and steel rely heavily on fossil fuels and have high carbon emissions. The energy to heat and cool and provide illumination is intensive. Transporting materials over thousands of miles is quite difficult to quantify for carbon emissions and, therefore, difficult to reduce.

It seems clear that a pathway to an energy positive building goal can be elusive, as it’s not possible to fully determine or eliminate out a building’s climate impacts. What can be done to remedy this situation?

“Decarbonization” is known by other names such as “low carbon” or “net zero.” Regardless of the nomenclature, reducing energy consumption and carbon emissions has gained traction for communities and organizations around the world. Climate benefits are a primary goal, but secondary results include major impacts on human health and social equity.

Construction emissions will consume a greater share of emissions in the coming decades, even as operational emissions from heating, lighting, and other functions diminish. Concurrently, a global building surge is expected to double floor area by 2060, a rate equivalent to adding an entire New York City to the world, every month, for 40 years.

Yet the 21st century has also seen the emergence of a hopeful green building movement. Some architects and builders have accepted the challenge to try to shrink the environmental footprint of building construction. These innovators within the building industry are starting to redesign their interactions with materials to address the climate crisis while also meeting the vast global demand for newly built space.

And advances in technology and green-building laws are pushing ambition higher than net zero. In fact, projects are being labeled “energy positive” — it’s a nod to buildings that give back more than they take, whether in terms of energy or carbon.

Energy Positive Approaches can Change Buildings’ Carbon Emissions

The US Green Building Council (USGBC) explains that operational carbon strategies are focused on lowering energy use intensity (EUI) and carbon intensity through efficient building systems, high-performance facades, behavioral changes, and renewable energy generation.

Embodied carbon strategies today tend to focus on the largest volumes of materials—which, for new construction, are the project’s foundation, structure, and enclosure. Designers and engineers who focus on energy positive buildings, however, admit that they don’t know enough about the carbon intensity of the materials they build with to say conclusively that their buildings are also carbon-negative. That’s why their areas of interest lie with more efficiently built and operated buildings.

Because humans today spend so much time indoors, energy positive buildings are particularly important mechanisms to improves the lives of those who live, work, and play inside. What are some attributes of buildings that boast energy positive results? Some might incorporate wave energy or kinetic energy from roads. Wind or geothermic energy. Angled roofs are common. Solar power continues to be a main focus.

Biogenic measures incorporate biological materials, equipment, and processes as the foundation for buildings. This model is characterized by its green, low-carbon nature and its harmonious integration with the natural environment. Bio-based materials are renewable because they don’t rely on a limited resource, do not require large quantities of energy to produce, and can naturally be altered into another form useful to life. Biogenic approaches take into account carbon absorbed by timber and straw in the building during its former life as trees and crops .

Creating all-electric buildings will further reduce dependence on fossil fuels — which are used for space and water heating, as well as commercial cooking  –and is an additional key step toward the decarbonization of building stock.

Examples of Energy Positive Buildings around the World

Several buildings deserve recognition for their energy positive capacities. Here are a few notables.

Colorado: The Populus hotel in Denver has biophilic architecture due to the use of sustainable materials and systems during its construction, like lower-emissions concrete. The management sources food from regenerative farms and ranches and uses an on-site biodigester to compost 100% of food waste. The Populus’ Road to Carbon Positive dashboard tracks these efforts to reduce embodied and operational carbon as well as offsets from renewable energy certificates and high-integrity nature-based carbon credits, “ensuring transparency in our environmental impact.” There’s no car parking on site, and the lobby’s wood furnishings come from reclaimed snow fences from Wyoming and beetle-damaged trees from Colorado.

Virginia: Fleet Elementary is the second net zero energy school for Arlington Public Schools. Home to PreK–5 students, the new building was completed in 2019 and earned LEED Gold certification. Despite the site’s compact footprint, the team at VMDO Architects was able to orient the building from east to west and stack it in a way that created “a series of tiered roof spaces with enough area required for the [photovoltaics],” says Wyck Knox, a principal at VMDO and lead architect on the firm’s work for APS.

Louisiana: Between 2016 and 2020, New Orleans conducted energy audits at approximately 50 city properties, resulting in a lengthy list of desired energy-efficiency upgrades. The city has already implemented 39 of those projects — mostly centered on HVAC and lighting improvements, which have helped to decrease overall energy use in city buildings by 23%. Grant money will fund additional upgrades in 41 city buildings—including 14 rooftop solar installations.

Norway: The successful Powerhouse concept of energy-positive buildings is breaking new ground with construction now underway of the first Powerhouse homes in Trondheim, Norway. With 200 apartments, the Powerhouse Lade project demonstrates how homes can become part of the climate transition. Powerhouses are all energy positive. The upfront energy cost of each building, and that of later demolition and disposal, is expected to be made back over the building’s lifetime, as reported by Bloomberg. The buildings will produce more energy than they consume over a lifetime of 60 years. Powerhouses sometimes draw from the grid, especially in winter, but in the long Nordic summer days they give back many times over, overspilling excess solar energy into surrounding homes and businesses. Some Powerhouses reuse concrete and steel from original 1980s buildings.