Introduction | Impact of Decisions | Key Concepts & Best Practices | Commercial Buildings | Residential Buildings | Industrial Buildings | Acknowledgements
Residential Buildings
Residential buildings are where we sleep, eat, grow up, and raise families. In the wake of COVID-19, we found ourselves spending an increasingly large share of time in our homes.
An energy audit is one of the first steps one can take to discover the best way to make a home more efficient. A home energy audit creates a customized path to become more energy-efficient based on your individual home and the way you use it. Many local jurisdictions and utilities offer rebates to help offset the cost of an energy audit.
Interested in scheduling a home energy audit?
Learn more here:
If you live in, manage, own, or are thinking of developing smaller scale multi-family housing, you can benefit your bottom line, improve the health of those who live in the building, and reduce emissions by working toward net-zero housing. These homes are less expensive to build because they don’t need a gas hook up, and they have lower electric bills due to their efficient design. In some cases, homes produce more energy than they consume through on-site energy generation that exceeds the needs of the efficient home.
Best practices to make your home more energy-efficient include:
Switch From A Gas Stove To An Induction Stove. Induction stoves, which look a lot like traditional electric stoves, quickly heat surfaces using magnetic energy. These stoves heat faster than traditional electric or gas stoves, thereby allowing individuals to cook faster. Induction stoves also reduce risk of burns or fires. Not only does this allow for more precise and safer cooking, but it also conserves energy and avoids harmful emissions from burning gas.
A study from RMI, Mothers Out Front, Physicians for Social Responsibility, and the Sierra Club found, “gas stoves may be exposing tens of millions of people to levels of air pollution in their homes that would be illegal outdoors under national air quality standards.” The EPA also found that homes with gas stoves have roughly 50% (but up to 400%) higher levels of Nitrogen Dioxide (NO2) than homes with electric stoves.⁹ This indoor air pollution has harmful effects on people, such as increasing risk for asthma.
Install Air Source Electric Heat Pumps. Air source electric heat pumps are significantly (200-300%+) more efficient than gas equipment resulting in operational cost savings. In order for Colorado to meet its sustainability goals, electric heat pumps will need to comprise over 60% of residential heating equipment sales by 2030 and over 95% by 2040, up from about 2% today. In Colorado, Group 14 Engineering and Community Energy Inc. conducted a study that evaluated system options, economics, and strategies to achieve electrification of buildings. The study found that for single family homes, the upfront cost of all electric space and water heaters is about 25% less expensive than homes with comparable natural gas-powered equipment.
Install Solar Panels. Solar is a clean and abundant renewable energy source. Solar panels can be easily installed in conjunction with utility providers (such as Xcel Energy). Solar panels can be an efficient way to generate electricity for your home and can be installed at any point.
Want to learn more about how you can install solar in your house? Click here.
Refrigerator/AC and Heaters. Ask the manufacturer of your refrigerator and your AC units if they use harmful hydrofluorocarbon (HFC) chemicals. HFC chemicals have thousands of times the warming impact of CO2 and are therefore being phased out of most cooling products. HFC chemicals require proper disposal. If you are looking for new appliances, opt for an energy-efficient, climate-friendly cooling product. Explore products here.
Install Double-paned Windows. Double-paned windows help insulate your home by keeping the heat or AC locked into the room, so that it will not escape through windows or insulation.
To learn more about energy efficient windows, click here.
Practice Eco-friendly Habits. Small behavioral changes can make a big difference in the grand scheme. Regulate your electricity use by unplugging unused cords and appliances and turn off lights in rooms that aren’t being used. Additionally, you can install timers for lights and thermostats to only use energy when it’s needed. To better regulate internal temperature, rely on shades and upgraded windows. These easy practices decrease emissions and save money on monthly energy bills.
Residential Building Case Studies
Single Family:
The Cohen family in Lakewood, CO built their family home with two unique systems that vastly reduce the home’s emissions: geothermal heating/cooling and solar generated electricity. Well established with most electric companies and easy to install at any time, solar panels greatly reduce electricity costs and can generate rolling credits for excess electricity created. While the largest cost is the upfront installation, the return on investment for this system is typically 10-12 years, depending on the number of solar panels, the amount of sun received, and the energy needs of the home. The geothermal heating and cooling system requires upfront planning and coordination between the general contractor and utility company. While the upfront cost of these installations are quite high, the savings and impacts over time more than make up for the cost. The geothermal system, which requires significant drilling and engineering, is not economically viable for a retrofit or remodel, but coincides well with a new build. The Cohen family stresses that while they could have sacrificed these systems for more conventional choices, they could not pass up the environmental benefit and the economic pay off over time. They chose these systems not just to be green, but to increase the livability of the home, decrease ongoing energy expenses, and increase the resale value of the home.
“My recommendation is do your research in advance or you’ll miss the opportunity. It’s easy to miss. Our planning process took many years. This needs to be an early component of the plan.”
Learn more about geothermal heating here.
To learn more about net-zero residential housing projects, click here.
Multi-Family Small:
Aspen Skiing Company’s Willits Block 9 is a 134-bed, $22M worker housing project in Basalt, Colorado that is directly adjacent to the bus line, a 25-minute ride to Aspen, and a few minutes from company offices. The building is entirely electric and highly energy-efficient, with EV chargers and a bike share onsite.
“Willits Block 9 employee housing busted two myths about electric buildings. It’s an example of cold-climate use of heat pumps which is something many engineers say is not possible. That’s important because the technology has arrived, but the industry is not aware of it. Second, the building’s operational costs will be approximately equal to an equivalent natural gas-heated structure, even in a region with cheap natural gas.”
Learn more about this project HERE.
Multi-Family Large:
Hirschfeld Tower in Denver, CO is a low to moderate income residential property consisting of 209 units. Originally built in 1967, the property was renovated in 2008 with the intention of increasing efficiency and comfortability while lowering costs, reducing maintenance, and minimizing the carbon footprint. After much research, the retrofitting project team utilized a closed loop ground source heat pump. The heat pump system consists of plastic pipes built underground and functions by removing heat from inside the complex to cool individual apartments or extracting heat from underground to heat the space. However, the system is designed to take advantage of natural heating and cooling whenever possible, which saves money and heavily reduces GHG emissions.
The team weighed the pros and cons of a geothermal heat pump system, a conventional mechanical heating and cooling system, and a hybrid system combining geothermal heat pumps and conventional heating and cooling. The results indicated that it would cost the same to install a traditional mechanical system as it would be to install the heat pump system. They also found that while installing a heat pump would cost the same as installing a hybrid system, the maintenance and infrastructure costs of the hybrid system would be higher. As a result, the Hirschfeld Tower’s geothermal heat pump system costs less than $.50 per square foot to operate compared to the $1.00 per square foot cost that the previous mechanical system cost. Implementing this system has reduced both the operating costs and the building’s carbon footprint.
To learn more about sustainable multi-family developments, click here.
“The dream of my grandfather, A.B. Hirschfeld, was fulfilled in 1947 when he completed The A.B. Hirschfeld Press Building — a glowing example of timeless Art Deco architecture that was home to his 80,000 square foot state-of-the-art printing plant, the largest between Chicago and the West Coast. A bigger dream was realized posthumously in the year 2000 when A.B.’s prized architectural possession was saved from the wrecking ball by Denver’s Sage Hospitality, conserved and repurposed in the form of a 122-room extended stay hotel — Towne Place Suites by Marriott. How proud A.B. must be to have his creation preserved and utilized for generations to come.”
A larger-scale project or full area redevelopment has an even greater opportunity to have an impact. You might want to consider creating a multi-building interactive system, where several buildings communicate with one another through grid interactivity to optimize performance and lower energy needs and costs. Larger scale projects can offer a higher return on solar and storage energy systems and can leverage thermal energy to create a more passive heating and cooling system.
9 The Inside Story: A Guide to Indoor Air Quality, Environmental Protection Agency