Zero Energy certified homes get all of the press and it’s understandably so. These homes produce as much energy through renewables (typically roof-mounted solar photovoltaics) as they consume on an annual basis and there is no doubt in my mind that they represent the homes of the future. So why shoot for a lesser target?
Most new homes in the Pacific Northwest need a large array of solar panels that cost somewhere in the neighborhood of $20,000 - $30,000 to produce enough energy to match their annual consumption. Yes, you can lower that number through efficient design, optimizing the energy efficiency package, economies of scale, utility incentives, and tax credits but thinking that home builders are going to be able to bear that burden of cost on every home they build is simply delusional.
I have a co-worker who’s grown tired of hearing me repeat the mantra that we should “eat our energy efficiency vegetables before our renewable dessert” but this statement cannot be over emphasized. There are so many ways to lower a home’s operational energy efficiency that can be cost effectively applied during the design and construction phase that are often overlooked. The opportunity cost of designing a home with forced air heating and cooling ductwork built into unconditioned spaces like crawlspaces and ventilated attics should be considered shameful. Once a home is built that way it is very unlikely a homeowner will ever find a cost effective way to remodel their home that allows for the duct work to be brought back inside the conditioned envelope. With ducts located outside of the conditioned envelope the forced air heating and cooling system loses significant amounts of energy both through air leakage and conduction every time the system is on. These energy losses are now locked into that home’s energy profile for 100+ years. The same can be said for homes with inefficient: shapes, orientation to the sun, window placement and orientation, and overhang depths. Even things that can be updated over time are unlikely to be changed until they’ve run through their useful life. How cost effective is it to replace a perfectly good 92% AFUE single stage motor furnace with a 98% AFUE ECM motor furnace? How about a .82 EF tankless gas water heater with a .99 EF tankless gas water heater? How about tearing out new R-30 fiberglass batt floor insulation just to install R-38 fiberglass batts? How about replacing new appliances with ENERGY STAR rated new appliances? The list goes on…
Our industry should focus like a laser on highlighting the features, advantages, and benefits of homes that have smart energy efficient design; energy modeled to perform at net zero energy with an appropriately sized solar PV system; and tested / certified by a third-party to guarantee reliable results for the builder and the buyer. I am confident that coupling this package with simple upgrades like solar ready and electrical vehicle ready infrastructure will lead all homeowners to install a solar PV system to meet their family’s needs. After all, the efficiency of solar PV systems have nowhere to go but up, and as the market expands, the costs will have nowhere to go but down. Let’s also consider that electric vehicles, the need for built-in cooling, technological advances in heat pump technology, induction cook top ranges, and more are driving the electrify everything movement. All of these factors combined will naturally lead homeowners to the decision that installing solar PV isn’t just right for their family’s eco-foot print, or eco-bling, but simply a wise buy from a purely financial perspective.
What about homes that simply don’t have sufficient solar access due to neighboring buildings, trees, or similar? That’s even more of a reason to focus on the efficiency side as community wide solar buy-in options will eventually come on line and as utilities themselves will make the switch towards a 100% renewable portfolio.
If our industry continues to advocate for lofty goals without paying attention to the real life cost implications well intentioned ideas are sure to tabled until the next round of political debates when the costs for solar have come down. Meanwhile thousands of homes will be built too inefficiently to be easily converted to net zero energy and will continue to operate that way for decades to come. A zero energy future doesn’t have to be so expensive or out of reach if we focus on the important parts first.