Photo by Birgit Loit on Unsplash
Much of what we take for granted in our homes – air conditioning, heat, electricity – comes at a cost. Or, more accurately, two costs. There’s the money you spend on energy, and then there’s your energy usage’s impact on the environment. High-performance homes change that picture – their substantial energy savings benefit both you and the planet. An accessory dwelling unit (ADU) can be a high-performance home too – read on to learn more.
A high-performance home is a residential space built to prioritize energy efficiency while exceeding traditional homes’ comfort and health. High-performance homes typically achieve net-zero energy and minimize water usage. They also include heat pumps and high-quality HVAC systems that heat and cool the space exactly enough for its size – no more, no less.
Also part and parcel of high-performance homes are fresh-air ventilation that combats air tightness while boosting indoor air quality. The home’s building envelope will also be designed so that mold growth barely occurs, if at all. Any living space, whether a single-family home or an ADU, is a high-performance home if it checks most or all of these boxes.
The lower energy use of high-performance homes typically results in lower utility bills and fewer negative environmental impacts. The indoor air quality in high-performance homes is almost always superior, and that’s great for anyone with allergies or respiratory conditions. Plus, these homes save water without reducing water pressure, which can come in handy during California’s increasingly frequent droughts. And to put a ribbon on this all, high-performance homes often cost less to maintain and operate than traditional homes.
The main goals of a high-performance home include:
Net-zero living is the closest you can get to having a carbon footprint of zero. A net-zero home reduces the energy usage of a traditional home by exactly as much energy as it uses. For example, the average home’s annual carbon emissions are 7.5 tons per year. If you moved from such a space into a home with emissions of 3.75 tons per year, you would be living net-zero. That’s because you’ve cut your carbon emissions by 3.75 tons, the exact amount of carbon you’ve used.
Energy costs have steadily increased since 2021, and building high-performance homes is a great way to balance out the impact of these rising rates on your household budget. High-performance homes typically reduce energy usage by more than enough to make up for increased energy costs. For example, let’s say your new high-performance home lowers your energy costs by 20 percent compared to your old traditional home. That’s more than enough to offset the 5.6 percent increase in electricity costs in 2021.
Green homes conserve more than energy. They also conserve water – and anyone who has lived in California during one of its droughts can understand why that matters. High-performance homes conserve water without lowering your water pressure, meeting the qualifications for restricting water usage without impacting quality of life.
A stuffy home might not always feel comfortable – and a high-performance home will never feel stuffy. That’s because these homes cycle out stale air at a controlled rate and replace it with fresh air that enters through clean air ducts. The result is a home that feels more comfortable and simply is healthier: Clean, fresh air passed through high-quality filters is better for the body. It’s also a miracle for anyone with allergies or respiratory conditions.
High-performance homes are also much better at withstanding mold growth and natural disaster impacts. Their stronger building envelope blocks much more water from seeping through the walls, floor, or ceiling, giving mold less chance to grow. Certain types of insulation used in high-performance homes can also better support the home in the event of natural disasters such as hurricanes. The result is a home that’s comfier and healthier for longer.
The most important features of a high-performance home include:
A high-quality building envelope makes your walls, floor, and ceiling all but impermeable to water. It also minimizes the occurrence of “thermal bridges,” which are gaps through which more air than the ideal amount can flow. These bridges can introduce more hot air into your home during the summer or cold air in the winter. That means you’ll need more energy to heat and cool your home. A robust building envelope counters this problem.
A continuous insulation layer goes hand in hand with an improved building envelope. That’s because, like the building envelope, your home’s insulation exists in the walls, floor, and ceiling. It can also be home to airflow gaps around your wiring, ductwork, and plumbing. A high-performance design addresses these gaps and results in a more efficient home.
In traditional homes, there are typically air gaps in your ceilings and roof, as well as near your windows and chimney. This air can pick up contaminants in the walls, ranging from dust to microorganisms. The result is increased, unnecessary airflow of unhealthy air. High-performance homes solve this problem with improved building envelopes and insulation alongside energy recovery ventilation (ERV) systems.
An ERV system exchanges stale air for fresh air at continuous rates while recovering energy from this stale air. This energy can then help power your home. When combined with better building envelopes and insulation, ERV systems result in fresh air that can only enter through the ventilator. That’s as close as you can get to an airtight home.
A high-performance home will include a programmable thermostat to lessen your energy usage. With the best of these thermostats, you can program a full week’s worth of temperature control at once. That’s easier on you and your HVAC system, which can run more consistently and for longer. The result is a longer-lasting, more efficient HVAC system that saves you money and energy on every front. It also reduces the amount of carbon your home emits.
If you’ve ever stood near a window on a winter day inside your well-heated home, you know that windows aren’t always well-insulated. That’s far less true with low-emissivity windows, which add a fine layer of metal atop the glass. This metal reflects ultraviolet rays and, more importantly for your home’s climate, solar radiation.
The less solar radiation that enters your home, the less impact the outdoors has on your temperature indoors. The result can be up to 50 percent greater energy retention. That means utility bill savings more than large enough to make up for low-emissivity windows’ higher costs.
Just as asphalt can get scalding hot on summer days, a dark-colored roof can roast in the sun. The problem is that some of this roof heat can sink into your home. The portion that doesn’t sink into your home goes into the environment, and that’s also a problem if all your neighbors have dark roofs. Collectively, all those dark roofs can add to the “urban island heat effect.” Cool roofs solve this problem while preventing rooftop heat from seeping into your home.
A roof qualifies as cool if it meets two requirements. The first is a white or light color that doesn’t absorb heat. The other is that the roof is built from reflective materials that direct heat away from your home. As a result, your roof isn’t constantly emitting heat into your home or neighborhood. That means your HVAC system won’t have to do nearly as much work to control your climate.
Although some traditional HVAC systems boast Energy Star ratings, alternative high-efficiency HVAC systems are still superior for high-performance homes. These systems include air-sourced or geothermal heat pumps – and, sometimes, eco-friendly biomass stoves – for use during the cold months. Heat pumps work in reverse during the summer, when they pump hot air out of your home into the world outdoors. At any time of year, they’re known to be highly efficient.
A high-efficiency HVAC system also includes the right filters – namely, filtration systems with Minimum Efficiency Reporting Values (MERV) of at least 13. A filtration system’s MERV tells you what percentage of particles between 0.3 and 10 microns in size it filters. MERV 13 filters are thus at least two to six times as efficient as traditional-home HVAC filters, which range in MERV from two to five.
Electric-powered hot water becomes unavailable when the power goes out. That changes with the solar water heaters common among high-performance homes. These heaters can operate at any time since they convert sunlight to electricity – and store that energy until you use it. They also use less energy to do their job, which is another way that high-performance homes benefit both your wallet and the environment.
The size and placement of your windows can affect the amount of energy you use to light your home. There can be a similar effect on your heating and cooling. That’s why many high-performance homes follow the Department of Energy’s advice to include northern-facing windows. These windows let in plenty of natural light, but with minimal glare and heat gain. That means you don’t need as much artificial light or, in the summer, cooling to make your home comfortable. You’ll feel – and see – better while using less energy.
When you do need to use artificial lighting, choosing LED lights over traditional incandescent or fluorescent bulbs is always the high-performance choice. Although all artificial lights lose some amount of their energy to heat, this effect is virtually nonexistent with LED lights. That means your artificial lighting doesn’t accidentally heat your home too. LED lights also use much less energy, further lowering your home’s carbon footprint.
Keeping your home high-performance is an ongoing mission. That’s where home energy audits come into play. These audits can identify inefficient appliances, electrical circuits, insulation, airtightness features, and utility lines. After an audit, the auditor will tell you what changes to make – whether tangible home modifications or broader lifestyle changes – to maximize your home’s performance. Audit your home regularly, and it should stay high-performance for good.
To certify that your home is high-performance, you can seek out the following certifications. If you successfully get certified, you’ll know your home is performing well.
All kinds of homes can qualify for these high-performance certifications, including ADUs. In fact, Spacial ADUs meet most requirements for Passive Home certification. And that’s just one of the many ways in which our ADUs are high-performance.
High-performance homes benefit the world beyond your home as much as they improve the environment inside it. So too do high-performance ADUs, and at Spacial, our ADUs are prime examples. Our studio and one-bedroom ADUs meet most Passive Home requirements. They also generate energy through solar photovoltaic (PV) rooftop systems and use high-efficiency HVAC systems and water heaters. Plus, the living room’s large glass sliding door lets in enough natural light that you can use less artificial lighting – and thus less energy.
Our team is just as high-performance as our ADUs. We’ll oversee your ADU’s permitting, site preparation, foundation pouring, off-site construction, and on-site installation – you can just sit back and relax. You’ll barely notice us – we’ll need only one day to crane your ADU into place on-site. And then, before you know it, you’ll have the keys to a high-performance second home in your backyard. Contact Spacial to start your journey toward a high-performance ADU perfect for housing aging parents, recent college graduates, and tenants alike.