Advanced building science approach to home performance yields big reductions in home energy consumption.
Last week I wrote here about how the new field of building science has made the home performance and Passive House movements possible, and that building science praxis today is really a continuum that progresses from simple energy retrofits (that require only rudimentary building science) through to high performance Passive House buildings (that require the most advanced building science).
Today’s post focuses somewhere in the middle of that continuum of praxis, at the point where advanced building science and home performance practice meet: short of full-on Passive House construction, but well-beyond your standard weatherization project.
The fact is that building science experts are transforming the field of home performance audits and home energy retrofits today. Backed by a rigorous understanding of building physics and dynamics, advanced building scientists can model, design and implement home energy retrofits that eclipse conventional home energy efficiency improvements.
“The field of building science has grown up and is now driving reductions in home energy consumption that would have seemed impossible ten or twenty years ago”, explains Hammer & Hand co-owner Sam Hagerman. “We’ve assembled a home energy performance team of crack building science technicians here to harness this new power for the benefit of our clients and the planet.”
The typical home performance technician not trained in advanced building science is forced to rely on a boilerplate approach in the field, applying prescriptive retrofit solutions aimed at satisfying the requirements of the latest governmental weatherization program. While this approach does achieve some reduction in home energy consumption, it falls short on two counts: it squanders money on prescriptive home energy solutions that may not address the unique problems of a given home; and it results in energy retrofits that will likely become obsolete in 10 or 15 years, or whenever the next weatherization program comes along.
Advanced building science, on the other hand, revolutionizes home performance audits and home energy retrofits because it empowers the building scientist to optimize homes through a performance approach, using sophisticated modeling to tweak air tightness, insulation, ventilation and other building component variables to design the most cost-effective home energy retrofit possible for each unique home. This leads to better solutions with bigger return on investment, and energy efficiency gains that are well ahead of the curve – retrofits that will stand the test of time.
“Everything is about optimizing”, says Skylar Swinford, Certified Passive House Consultant and leader of our building science team. “Take heat recovering ventilation systems, for instance. I love HRVs because they conserve energy that would otherwise be lost in a home’s exhaust air. But when we do the math, if the building science tells us that super-insulation is a more impactful investment for a given home, then we prescribe that ahead of an HRV, and switch to a more basic continuous mechanical ventilation system. Each variable is scrutinized and fine-tuned for optimal performance.”
The Passive House movement, widely recognized as representing the cutting edge of building science and home energy performance, fuels our building science expertise. “Because our team’s building science lineage traces directly to the rigorous Passive House training that we’ve undergone,” says Sam, “our suite of home energy retrofit measures comes straight from the Passive House high performance playbook.” This suite includes:
- Aggressive air sealing to create a nearly airtight building shell.
- Continuous mechanical ventilation to provide constant flow of fresh air – often a heat recovering system for better energy performance.
- Intensive, high quality insulation, with low global warming potential – usually cellulose or water-blown spray foam.
- Computer modeling to optimize the performance and value of the home energy retrofit package.
“When we are smart about home energy performance audits and retrofits, and bring advanced building science to bear,” says Sam, “it’s a win for each individual client who receives better home performance for the money – greater comfort, safety, and energy savings. But it’s also a win for society at large, because we’re taking full advantage of every retrofit to significantly reduce the energy consumption of our built environment.”
– ZackBack to Field Notes