You can't call a home "green" just by outfitting it with efficient products. To do it right, architects are approaching sustainable living with a holistic approach, starting with design. Buildings are constructed using renewable and high quality sources, and implementing smart water, HVAC and electric systems. Even waste management and outdoor spaces aim for sustainability.
Though it can seem like a lot of effort, the benefits of an energy-efficient multi-family residence are overwhelmingly positive for builders, owners and tenants alike:
- Unmatched ROI: According to the World Green Building Council, potential tenants are recognizing the benefits of green living and are willing to pay the premium for it ... and that means owners start seeing impressive returns in less time.
- Reduced tenant turnover: Significantly lower utility bills—up to 80 percent less than non-efficient utility costs—lower bills remind tenants of the value in green living, and keep them from looking for new housing.
- Less building maintenance: Using high-quality, eco-friendly products will reduce wear and tear on your building and increase its lifespan, which means less maintenance for owners and more happy customers (read: more business) for builders.
So what does it take to design and construct an energy-efficient complex? Check out my top eight picks to build an energy-efficient residence.
If you're not familiar with the benefits of a concrete build, brace yourself. Concrete is almost magical in a eco-friendly structure. Made with either limestone or waste byproducts, it's highly resourceful and minimally wasteful. A concrete structure can last 200% - 300% longer than those framed with other materials, and it won't rust, rot or burn in that time. Plus, concrete absorbs and retains heat—making it highly energy efficient and likely to cut down on future HVAC costs before that system is ever put in place.
On top of that, concrete is great for the environment, too. It's light color helps reflect more solar radiation, reducing the heat-island effect often noticed in urban areas. And when it's finally time to rebuild, concrete can easily be crushed and reused to create permeable pavement—more on that later.
While concrete is great for absorbing heat, having good insulation is one of the top factors in a highly efficient structure. Insulated walls, floors and ceilings are top priority in creating regulating internal temperatures and creating a tight envelope—a tight seal that keeps temperatures, wind and rain out. You'll have your choice in materials here, with options like insulated concrete and structural insulated panels. One of the more environmentally friendly choices is plant-based polyurethane rigid foam (PRF)—which is a heavy-duty foam made of bamboo, hemp, kelp and other plant fibers. Plant-based PRF is known for its ability to keep moisture, mold, heat and pests at bay, and it's R-value is higher than that of fiberglass or polystyrene. Plus, when used in multi-family dwellings, plant-based PRF will go a long way to keep neighbor noise to a minimum.
Keep UV heat and noise outside with double pane, low-emissivity (low-e) windows. Double pane windows use two panes of glass with air in-between (Tip: opt for argon or krypton gas instead of air for even higher efficiency). Low-e glazes are incredibly cost-effective, enhancing the window's insulation capacity with one or two thin metallic coats.
When possible, consider an open floor plan with plenty of windows to brighten the space inside and reduce daytime lighting and energy costs.
Low-efficiency roofs have a tendency to ruin all of the work that your well-insulated walls and windows are doing—they let cool air out in the summer, and let it back in during the winter.
Combat this in one of two ways: Super-efficient cool roofs can actively reduce internal temperatures by up to 50 degrees Fahrenheit by reflecting sunlight with highly reflective paint, tiles/shingles or a sheet covering. A community with multiple cool roofs can reduce outside air temperatures as a whole.
Green roofs, the second option, are popular on flat rooftops in big cities, where green space is otherwise hard to find. Green roofs feature plants or gardens that double as an outdoor oasis for residents and a storm water management system for building owners.
An energy-conscious hot water design will keep hot water available to all occupants within your multifamily units ... but with so much lightly used water being used by residents in their daily hand-washing, laundry and bathing activities, it is literally a waste to let it all go down the drain. This gray water—which does not include wastewater from toilets, kitchen sinks and dishwashers, etc.—is the perfect untreated resource to keep community lawns and gardens green all season long.
Graywater can even be used as part of a radiant heating system to keep homes warm in the winter. These systems make use of high-efficiency hot water heaters to heat graywater and pump it through under-floor water pipes throughout individual residences.
Make the most of the earth's energy with a geothermal HVAC system that converts underground heat energy to run internal heating and cooling processes. Geothermal HVACs use a loop of pipes that run down into the earth to pump heat energy or refrigerant, depending on the season, to residences above. Not only do geothermal systems last for generations, they’ve been known to save building occupants up to $100 in monthly heating and cooling costs. Add programmable control units to individual residences and savings can increase even further.
Alternatively, include an energy-saving trash recycling facility that goes much further than sorting papers and plastics to provide the ultimate in green living. Through waste gasification, trash is heated until it emits gasses, which are then captured and burned to create energy with minimum pollution.
A planned community that features a waste gasification system lets tenants create their own energy, resulting in free or low-cost heating and electricity. Your community stays clean, and its footprint is almost nonexistent.
The work isn't done when your structures are up and interiors are outfitted. Eco-friendly outdoor spaces can be just as important to an energy efficient property. Plants enhance air quality and help areas recover from over-urbanization. Using native plants from the region while landscaping your new build will enhance the site's sustainability, while also requiring less maintenance than imported shrubs.
If you're planning to reuse residents' graywater for irrigation as mentioned above, you're already a step ahead of the game—but don't forget to capture rainfall, too. When paving walkways, driveways and parking lots, look for a concrete permeable paver solution that allows rainwater to reach the earth and runoff into locally sourced vegetation or stormwater basins that collect rain for future use. Whether your build opts for graywater or stormwater irrigation, you'll need to plan the plumbing and draining systems carefully prior to the start of construction.
Keep Up With A Constantly Evolving Industry
New generations, new energy codes, new technology... The construction industry is rapidly growing and changing. It's nearly impossible for anyone to keep up with everything that's going on. The good news is, you don't have to. We've pooled our team's years of experience to create a library of free resources you can download today.