Ever Feel Like You Use Too Much Energy at Home?

It’s not just you. America’s residences use about 21% of all the energy the nation produces, and they emit about 17,300 lbs of CO2 per year. For perspective, you would produce that same amount by driving the entire length of the Pan-American Highway, from the tip of Alaska, to the tip of Canada, to the tip of South America… and then some. That’s a lot of carbon for our homes to waste.

Actually, buildings in general are far less efficient than we realize. Just building an average, 2,000 sq. ft. stick-built house (a house built from scratch on a plot of land) creates 8,000 lbs of waste. All that carbon goes straight to landfills, wasting money and resources, and creating more opportunity for leakage into the environment instead of safe sequestration.?

It won’t have to be this way for too much longer.

Architects are becoming more and more aware of the effect current practices have on the environment. Sustainable building materials and practices are in development to handle all of these issues. They come in many forms, from innovations in modern materials like concrete, to re-thinking the way a home can be built to create less waste, and even revitalizing ancient building practices for modern, upscale homes.

So how hard really is construction on the environment?

Manufacturing the steel and concrete used in nearly every building project creates 22% of all the embodied carbon created. And that’s the real killer in the industry, embodied carbon, the carbon released during manufacturing, transport, and installation of these materials. It will account for 74% of the emissions from all new buildings in the next 10 years.?

How much embodied carbon currently exists is hard to determine because of how many variables go into each process, and the amount of transparency companies involved provide, but it is part of the 40% chunk of greenhouse gas emissions that buildings contribute worldwide.

And none of this data factors in the amount of efficiency these materials provide to a building’s energy consumption needs.

The technology we use to stay comfortable at every temperature, prepare and preserve our food, and maintain a decent standard of living does its job well. But in the face of climate change, we know it is time to adapt and innovate further.?

Concrete is the second most widely used substance in the world, only second to water. And because of that, this single product is responsible for 8% of the world’s total CO2 emissions at 4 billion tons annually.

In June, we discussed carbon offset companies like CarbonCure or Solida, who developed processes to seal 70% of their carbon emissions back into the cement itself. Alongside that, companies are taking measures to reduce the need to produce concrete.

Engineered Cementitious Composite (ECC), known more simply as Bendable Concrete, contains fibers derived from polymers that increase its malleability, even when solidified. Because of that, it can flex with stress, it becomes more shock resistant, and is 500x more resistant to cracking. ECC can help us build stronger structures with less need for repair or replacement, less embodied carbon, and less energy consumption.

Precast concrete is also becoming more prevalent, allowing for less material and energy waste by sending customized concrete structures molded at the factory to the construction site. And 3D printed concrete offers many of the same benefits as precast concrete, with the added benefit of the precision, speed, and efficiency of a 3d printer.

Reshaping the concrete industry would restructure the world on its own, but that’s not the only way building materials are becoming more sustainable. Imagine a skyscraper- made from wood.?

That’s Mass Timber.

Various softwoods can be laminated (stacked perpendicularly) and glued into slabs called “glulams” that are stronger than steel, cheaper, quicker to build with, and less emissive. In fact, it's so effective that Brock Commons, a student residence at Oregon State University completed in 2017, was the tallest hybrid Mass Timber building in the world at 17 stories. Built from glulams, steel connectors, and a concrete base, the framework was able to be constructed at a rate of two stories per week, 4 months faster than the industry average.

In 2022, the title of tallest mass timber building is held by Ascent Tower in Milwaukee, completed in August and standing 25 stories tall.

A wooden building so large provokes well-deserved fire-safety concerns, which is why there are tough regulations on mass timber height limits and fire ratings. Both Ascent Tower and Brock Commons have met or exceeded fire code requirements, and have been granted a minimum of a 2-hour fire rating.

Just outside the mass timber space are SIPS, or Structural Insulated Panels. SIPS are a thick foam insulation sandwiched between two OSB boards, which become structural walls when installed. The OSB boards come from chips of fast-growing trees often overlooked for construction, and leave little unused. The inner insulation fills all the empty space, leaving no gaps anywhere. Up to 40% of a home’s heat loss comes from hidden leaks, and without those, a lot of energy is saved.

Other natural building materials are also getting more attention.

Bamboo has a higher tensile strength than steel, making it less likely to break under stress. With its compostable waste, rapid replenishment rates (3 years compared to wood’s 25-50) and the ability to use the whole stem in construction, it can be used in buildings, furniture, bicycle frames, and more.

Mycelium, yes, the fungus, can be combined with materials like timber, sawdust, and demolition waste, and then molded into bricks stronger than concrete and more insulating than fiberglass.

Bark, which is often wasted, is being used as an aesthetic feature in luxury homes and hotels, as siding, as a headboard, and more.

Rammed Earth is the material the Great Wall of China is made of, still being used in various kinds of construction. And it's only gravel, sand, silt, and clay between panels.

Straw bales are used in luxury residences as a substitute for lumber. They create walls much thicker than normal, but are very good at insulating and resistant to fire. And because these bales are recycled waste from farms, they are sequestering carbon that may have been otherwise burned for fuel or heat.?

Even the wool from sheep is being sold in rolls as an insulator 10% better than fiberglass. Its flame-resistant, sound-deadening, and completely biodegradable.

Come back next week for more sustainable solutions.