Building decarbonization strategy: It starts before electrification

First, we improve the building’s envelope. Then we assess the energy needs of the mechanical, electrical, and plumbing systems. Electrification is not the only way for us to decarbonize. The building industry is committed to eliminating GHG emissions. That goal requires creative and innovative market solutions and policies. That’s the message we need to prioritize.

Antonino Lagana: I agree. The first step is energy efficiency, or the deep energy retrofit. You want a building to use energy efficiently. That’s the common denominator in all energy landscapes. I’ve delivered large and small zero-carbon buildings. And I’ve electrified as far as you can electrify. I’ve peak shaved with carbon-neutral alternative fuels and energy storage. In many places, the electrical grid cannot currently provide enough power to fully electrify a building or a community. So, we need carbon-neutral alternative fuels like renewable natural gas.

Let’s talk about peak shaving. There are two types of charges on your building’s electrical utility bill. There is a charge for the energy cents per kilowatt hours, and then there’s also the billing demand. The billing demand takes your monthly peak demand and slaps you with a charge for that. You want to shave that peak.

You can prevent that peak by using thermal energy storage, which is what we’re doing for the Place du Portage, a large Federal project in Quebec. Or we can use fuel like renewable natural gas, as I’ve recommended for the garage at Place du Portage. We cannot electrify the heating in the garage because it requires too much power and it’s sporadic.

Can you tell us what zero-carbon-ready design means?

Antonino: So, to make your building energy efficient, we called that zero-carbon-ready. Why? We sometimes think zero carbon means enough solar panels or a wind turbine on a property to supply all the energy required. But wind and solar are too variable and take up space. Battery storage beyond six to eight hours is often cost prohibitive. And they need maintenance.

The truth is that delivering zero-carbon buildings at scale is feasible where the utility provides affordable clean energy. In Quebec, where I live, we have a “best world scenario” with clean energy from the grid, cheap electricity from hydropower, and affordable, renewable natural gas. The renewable gas is coming from our brown bins, existing landfills, and farm waste. They’re injecting that methane into the natural gas network. The province of Quebec has made great strides in electrification and renewable gas. So much is dependent on the grid, so we need to talk about zero-carbon-ready buildings.

We can turn existing buildings into zero-carbon-ready buildings, right? The scope of the energy retrofitting market is huge. What’s the tipping point for greater take up in the market?

Antonino: Everyone’s on board when there’s return on investment. ROI unifies everybody. There’s nothing wrong with doing a deep energy retrofit because it makes financial sense through energy savings and through timely equipment renewal. The approach varies from one energy landscape to another.

For example, where electricity is expensive, you can focus on reducing electricity consumption to get a quick payback period. In areas where natural gas is more expensive, you would focus on those retrofits. Measures that reduce your natural gas consumption, such as heat pumps, become more attractive.

In retrofits, you analyze each area of energy consumption. You examine each energy end use and find ways to reduce it. Typically, energy-service companies come into your building and look for ROI through energy savings and equipment renewal. But some clients like to go the traditional way and pay for their energy upgrade themselves. That’s because it’s less expensive for them in the long run.

Beth: New commitments and reporting requirements are also driving demand for energy efficiency or deep retrofits in the corporate world. Large corporations with environmental, social and governance commitments often must benchmark their existing building stock and report on the progress of their emissions reductions. Thus, deep retrofits deliver an extra return on investment when stockholders are paying attention to emissions. And they benefit social license.

ROI is also impacted by carbon taxes. The client’s payback on deep retrofits or a high-performance building design expands from energy cost and savings to also include GHG emissions and carbon taxes. The drivers for documenting and incentivizing deep retrofits are changing. Building owners can avoid that future carbon tax by investing in themselves today.

Can you elaborate on some of the other elements of deep energy retrofits? What’s changing there?

Beth: With older buildings, easy retrofit solutions usually included LED lighting, roofing, insulation, or window replacements. Traditionally, it was difficult to justify a deep retrofit. Those may include the structural elements to support rooftop photovoltaics or investment in exterior wall insulation. These more invasive changes require careful consideration and coordination. But once you make these hard investments, there are positive domino effects. For example, if you upgrade your wall insulation, you can downsize your boiler or your cooling systems. Project timing is critical to leveraging planned capital expenses, like large preventative maintenance projects or system replacements.

Antonino: Deep energy retrofits are the first step, the first brick in the wall. The US needs to get its energy consumption down, and buildings use a lot of energy. But we also must convert our energy supply to clean energy. There’s only so much clean energy right now. The US won’t be able to electrify transport and industry completely. It doesn’t have the supply or the infrastructure. So, the US needs to look at adding alternative fuels to its energy pie to reduce its emissions.

Beth: In temperate areas, it’s relatively easy to electrify. But in those areas with extreme heat and humidity or extreme cold, full electrification may outstrip current utility capacity. Additionally, we need to share that capacity with transportation’s electrification evolution. We should think about reserving carbon-intensive fuel for industries that desperately need it. We should use alternatives when we can. There are options: whether that means using heat pumps for most of the year and only using natural gas when urgently needed or using passive solar thermal to reduce natural gas demand.

These are the kinds of solutions we can offer and implement for our clients. We need to incentivize GHG emission reduction, not only from the design standpoint but to help the clients understand that these building performance standards are rapidly expanding across the US and Canada. Clients need to know that if they are implementing these solutions today, if they invest in a carbon neutral future through deep retrofits and energy transitions, they can avoid carbon tax expenses in the future.

Do we want to dip our toe into embodied carbon?

Beth: We do. Much like the regulation of the energy consumed to operate a building—and that energy’s associated emissions—new regulations are beginning to take shape on embodied carbon. Those are the greenhouse gas emissions associated with the materials used in the whole life of a building. The State of California is implementing an embodied carbon requirement for new construction. That legislation should be in effect by 2025.

As designers, we master plan projects for our clients and their campuses that look out to 75 years. So, clients need to prioritize adaptive reuse of existing buildings wherever possible.

What about building life? You're getting more from that investment in embodied carbon and money from the 50-year building than a 30-year building, right?

Antonino: At Place du Portage, the structure is already about 50 years old. We’re conserving the structure so that we don’t have to pour new concrete and needlessly add materials that have embodied carbon.

So, for embodied carbon, our strategy is to retrofit the building and keep as much of the material, the concrete, and the steel, as possible. We will redo the fenestration with a triple glazed curtain wall to make it efficient. The embodied carbon strategy is to conserve because that concrete could last a long, long time.

Beth: ASHRAE and the International Code Council are developing a new building standard for whole life GHG emissions accounting. This will drive new operational and embodied carbon emission regulations. It will be a code-enforceable standard for the building industry on emissions accounting. When it’s adopted, it will make whole life cycle analysis for buildings possible. We will be able to compare proposed design performance of a building design or major remodel. This will influence industry.

Building developers often think in the short term. But if new building standards are adopted, they don’t want to leave their assets stranded. When you start talking about climate adaptation, if you’re not addressing risk up front, then you may incur risk. There may be damage. You may need to demolish or repair or rebuild. That’s also incurring embodied carbon for your portfolio.

The industry is codifying greenhouse gas emissions accounting for buildings. So, we need to consider emissions of right-sized systems against those of robust structural systems.

Ideally, we create a holistic carbon-neutral design. It will balance emission reduction and tomorrow’s risk.

Are you hopeful about the opportunity to make a more sustainable built environment?

Antonino: In an ideal world, the utility provides clean, affordable energy and the building owner makes their building energy efficient. The US needs to increase the supply of clean energy. The government could set up conditions so that it’s favorable to utilities to provide clean energy. Then it’s a matter of building owners doing their part to retrofit their buildings.

I think it’s engineers like us who should be advising the government rather than just business leaders. We develop solutions every day and can say, “Look! These are the most promising leads. This is how it can be done.”

Beth: I’m incredibly hopeful. This is the most exciting time to be an engineer.

We’re a part of the greatest transition in the building industry. Change is incentivized by governments, and change is demanded from the social level, pushing corporations to do better.

The transition is happening at all levels; and it’s very exciting. From corporations, building owners, and industry leaders in the insurance and financial sectors to local governments, utilities, and manufacturers—the transition is happening.