UPDATE: A letter-writer to the Monitor pointed out that burning wood for heat (as Concord’s downtown did fairly recently, until Concord Steam went belly-up) is a renewable option for the new school that I didn’t mention.

As if building a new school wasn’t complicated enough, here’s something else that Concord needs to accomplish when it replaces Rundlett Middle School: Contribute as little as possible to the global environmental disaster.

Because any new school will be around for at least three decades (Rundlett dates to 1957), decisions made now will be affecting the planet when today’s students are facing middle age and Earth is facing a temperature increase of 1.5 degrees C or more. With the city’s tough clean-energy goals in mind, a new Rundlett School should do as little as possible to contribute to that dire scenario, either by being “net zero” from day one, meaning it can produce as much energy as it uses, or by being built in a way to easily become net zero as technology improves.

Concord City Council has set a goal of having 100% renewable electricity throughout the city by 2030 and 100% of heating and cooling from renewables by 2050. Even though the Concord School District is a distinct entity from the city, a new middle school is likely to be the first big project in Concord since those objectives were announced. If it falls short, that would bode ill for the goals city-wide and the school district is aware of this.

“We want this to dovetail right into what the city is doing,” said Matt Cashman, director of facilities for the Concord School District. He noted that City Councilor Rob Werner, point person for Concord’s clean-energy push, is slated to swap ideas with the School Board at that group’s Oct. 4 meeting.

Fortunately, creating a building that doesn’t need any outside energy isn’t as extreme a goal as it may sound.

“It’s an idea that has been around for a while. The last decade or so has seen it grow; there are now many examples of net-zero-energy buildings, let alone net-zero-ready,” said Paul Leveille, whose title is High-Performing Buildings Coordinator with the Concord-based firm Resilient Buildings Group. “It has evolved because technology evolved. Heat pumps get more efficient, lighting gets more efficient and the efficiency of solar electric climbs upward. … And (solar) is certainly less costly; that’s the big news these days, the cost.”

“The extra work that it involves (in design) is to do some energy modeling. … You’re asking what-if questions – what if we do better insulation, better windows, like that – and modeling all the what-if scenarios until you get to the final energy use intensity that you’re looking for. It’s not actually that much more work,” he said.Big decisions to come

Although the idea of replacing Rundlett has been discussed for a decade, these are very early days for development details. Notably, the school board hasn’t decided on three basic questions: whether the new school will include grade 5; whether they will replace the current school or build somewhere else; and whether the school will somehow join forces with the YMCA.

It’s hard to make long-term environmental decisions without that information, said Chapman: “Footprint determines just about everything.”

For example, geothermal energy. Those systems run fluids through underground pipes to tap the earth’s constant temperature and can greatly reduce energy needed for air conditioning and heating systems. It’s an obvious choice for a large building like a school but until a location is chosen, who knows whether it will be feasible for the new Rundlett?

The decisions will need to be made fairly soon. The district wants to submit a letter of intent for the state’s all-important education building aid by Jan. 21, 2022, and will have to have its formal application in by July 1 to get in line for the money, Cashman said. 

Money is, of course, all-important. Net-zero construction is often more expensive upfront, and although it can save money over the long term because of lower fuel costs, the up-front cost usually drives decisions from voters and elected officials.Support the Concord Monitor. Subscribe Today 

One question is whether financial support for net-zero construction will come from the federal government via the infrastructure bill. That would make it a lot easier.Being net zero

At its simplest, making a net-zero building is just like making an energy-efficient building, plus solar panels.

“Step one is really conservation: Don’t use energy if you don’t need it. Then efficiency measures: Where you are using power, use it efficiently,” said Leveille. “Once you’ve done two things really well you’ve gotten the load so small you can explore use of some sort of renewable energy system to power it and get to net zero.”

Because there’s no renewable way for a building to generate a substitute for natural gas or fuel oil, net-zero means the school will have to be all-electric, including the heating system.

Electric heat pumps, which move heat between the inside and outside of buildings rather than creating new sources of it, have improved to be effective even in New Hampshire’s climate and are a major part of many clean-energy programs. Massachusetts, for example, has a goal of getting a million homes using electric heat pumps by 2030.

There’s also a secondary desire to minimize “embedded carbon” in the final building, a measure that reflects the amount of greenhouse gases released during construction.

“Right now, that’s a push in the industry. We’ve gotten pretty good at knowing how to make energy-efficient buildings. People are saying the next thing to examine is the amount of energy that goes into building materials,” said Leveille.

Life-cycle assessment software and other tools are being developed to estimate such things as how much carbon reduction you would get by replacing steel girders with cross-laminated timber.

Adding to the complexity: Reusing an existing building rather than building new is almost always better from the embedded-carbon point of view. It seems unlikely that Concord will try to upgrade the existing Rundlett Middle School building, however, partly because making it net-zero would be difficult.

“Ultimately this is all about our values. If you’re a building owner and looking to build a building, what’s important to you, what are your priorities?” said Leveille.

“We want to do what’s right,” said Cashman. “We need to be totally transparent the whole time, from the start, about the process.”

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