Are Deep Energy Retrofits and Electrification the Answer?

Quantity or Quality? Do we have a choice?

Building codes are great at making sure new buildings are efficient. But new construction is a small piece of the pie. The real challenge is the many buildings that are already standing. Older buildings, especially those built before energy codes were introduced in 1978, are energy hogs. At Efficiency First California, we focus on these existing buildings.

From the beginning, we’ve supported a holistic home performance process that includes a full on-site diagnostic evaluation (sometimes called an energy audit, energy assessment, or simply a test-in) and presents the customer with a comprehensive report that covers insulation levels, air tightness, heating and cooling system performance, the condition of the duct system, and other factors impacting energy use. The contractor then proposes various measures they could employ to improve their building’s performance.

The problem with this approach is that it is time-consuming and expensive. Multiple aspects of the building often need attention, making the home performance approach a significant financial commitment. I still believe this is the most effective way to improve a building’s performance, but not everyone can afford to fix all the problems in their buildings.

The question is, should we try to achieve the maximum benefit on every building retrofit, which impacts volume, or can we relax our approach a little to reach a much greater volume? Would you prefer to support a strategy that retrofits 1,000 homes a year and knocks it out of the park? Or would you be willing to make some compromises and impact 10,000 buildings annually?

As time goes by, I find myself supporting the latter. I am willing to let go of a few nuances in the name of having a more significant impact. Is there a sweet spot where we can maximize our impact and not compromise our core values? I think so, and clean electricity makes the decision more straightforward than it used to be.

Pros and Cons of a Comprehensive, Whole-Home Approach

The benefits of a comprehensive, whole-house approach are numerous. In addition to the energy benefits, a complete audit with a safety test ensures that any natural gas appliances in the home are working correctly and do not poison the occupants. This is no joke, as a simple thing like a misaligned flue can cause serious issues (there is a reason carbon monoxide is called the silent killer). Energy bills go down, comfort increases dramatically, improvements in indoor air quality mean the home is healthier, and managing moisture means the house is more durable. Improvements across the board mean the home is a much nicer place to live. The challenge is that the time and cost to do comprehensive projects are often out of reach for many people.

From a contractor’s perspective, the home performance approach has many upfront costs. Audits are complex and can be quite time-consuming—for a typical house, it can take two people four hours to complete the process. Generating a report and drafting a proposal also takes time. We tracked some of our projects and concluded that our average upfront investment was nearly 20 hours per project. All of this is before you have signed a contract with the homeowner.

I have had many conversations with several die-hard home performance contractors. The question on everyone’s mind is whether to maximize the impact on every home or building or bring volume to the industry. It’s a tough call, as I am a big supporter of the whole-house approach to retrofitting buildings. But as time passes and the industry has changed, so has my perspective.

A Sweet Spot With Electrification?

If you follow this industry, you know there is a massive push toward electrification. I support this effort for several reasons. Heating and cooling systems and water heaters are the largest energy consumers in buildings. California is unique because 95 percent of these loads are met with natural gas-burning appliances. Electric heat pumps are far more efficient than natural gas appliances, and because they use electricity, they can take advantage of the increasing amount of clean energy on the grid. If we swap out every furnace with an electric heat pump system and every gas water heater with a heat pump water heater, the impact will be huge.

But while I support this effort, switching out appliances alone is not the best solution. If you don’t address the building, you’re missing out on a huge opportunity for improved efficiency and comfort.

I have relaxed my hard-core home performance standards and slightly reduced my expectations. We must create a blend of home performance and electrification that we can scale. Today, I support addressing the building envelope with solid, time-tested home performance measures and switching to electric appliances. So, what exactly does that mean?

A Hybrid Approach: Electrification + Building Envelope Improvements

The building envelope, or shell, is the defining structure between you, the occupant, and the world outside. It includes walls, ceilings, floors, windows, and doors. Improved envelopes can reduce the size of heating and cooling systems, which reduces cost. Shell improvements reduce building loads, which helps with peak load on the grid.

I suggest every contractor does their best to include envelope improvements in the race towards electrification. Basic envelope improvements give occupants multiple benefits, such as improved indoor air quality, comfort, durability, and overall home performance. The cost of shell improvements is one of the lower-cost measures in the home performance arsenal, meaning we can bring scale to the effort.

Prioritizing Building Shell Improvements

OK, you’re sold. So, where do we start? New windows on every project? That’s expensive. Windows and doors are the last measures I would include. Instead, start with the low-cost fundamentals—insulation and air sealing—and go from there if you can afford it.

Air sealing and insulation are like peanut butter and chocolate. They go together well. An analogy most folks can relate to is that insulation is like a wool sweater (or jumper, depending on where you grew up), and air sealing is like a windbreaker. Wool sweaters keep you warm until the wind blows. A windbreaker with no insulating layers under it will stop the wind but won’t do much to keep you warm. Combine the two, and you will stay warm and cozy.

If you have ductwork in the attic, a common practice in California, put as much insulation on it as possible. Attics get hot; we are talking 140 degrees Fahrenheit. Imagine how hard your air conditioner is working to keep it at 78 degrees or less. The best practice is not to put ducts in the attic, if possible. If you’re electrifying the heating system in a house with ducts in the attic, consider ductless mini-splits instead. If there is no way to have the ducts inside the home, bury them in insulation. I mean that, literally. We suggest at least three to four inches of insulation over all the ducts. Deep-buried ducts have long been a solution in home performance projects.

A Compromise that Works

As time goes on, the electricity on the grid gets cleaner every day. It’s clear why there is a push to support and electrify every approach and the right choice. Electrification is the right path forward, but don’t forget the value of essential energy efficiency upgrades.

Simple energy efficiency upgrades to the building envelope, combined with all electric appliances, are much better than electrifying appliances. This hybrid approach is also a lower-cost alternative to comprehensive, deep energy retrofits. It can scale much faster, and it works. Sometimes, the perfect solution is a compromise. I am willing to compromise and embrace the building envelope plus electrification model if it means fixing tens of thousands of homes versus hundreds. What’s your perspective?

This article was originally published in the Efficiency First CA blog and is republished with permission.