David & Emily Takahashi Residential Project, Boulder, Colorado | David Takahashi reached out to Heart of a Building with his story after watching our video episode on Rocky Mountain PBS.
David and his wife, Emily’s sustainable home story began with a devastating fire. In 2010, they watched their home in Four-Mile Canyon outside of Boulder, Colorado, burn to the ground.
Three years later, David watched as the canyon experienced severe flooding that damaged their new home, which was under construction after the fire. David and Emily decided that rebuilding in the canyon would not be worth the price or risk of severe weather that he felt was becoming more severe [due to climate change], so they decided to relocate to central Boulder.
Their experience of watching their prior homes destroyed by two once-in-a-hundred-year events triggered the urge to consider the planet’s health and future through the choices they would make in their next home. They decided to make a difference and live in a house that was as sustainable as possible.
Despite the many challenges, David and Emily were determined to transform their new 1954 house into a net-zero or net-positive home. It wasn’t about saving money on energy bills — it was about saving the planet! Their empathy for future generations was the biggest driver for the project. David wanted to be able to have an answer to their grandchildren when they asked, “What did you do when the world was going to shit?” With this as his motivation, they have successfully retrofitted the 60-year-old home to a carbon-neutral home. They took steps that were cost-effective AND that are applicable for so many homeowners across the Mountain West and the entire United States. When they began, their new home had a HERS (energy rating) score of +190. (NOTE: The lower the HERS number, the greater the energy efficiency. A score of ~110 is typical of residential construction over the past 75+ years).
They worked to improve the energy efficiency and HERS score, dramatically with;
- adding cellulose insulation in the attic as well as dense-packing it into the exterior walls,
- the addition of new triple-paned windows,
- a cold-climate air source heat pump with a programmable thermostat,
- LED lighting,
- EPA WaterSense fixtures, and
- a 10.44 KW capacity solar PV system to provide ALL the electricity to their new all-electric home.
These improvements not only improve the HERS score but blow out of the water their HERS score which as of 2018 its score was a remarkable –50 (negative 50).
This performance was despite a heavy tree canopy cover that some solar PV installers predicted that the home would only be able to harvest 5% of its consumption via solar. David and Emily saw this as a challenge and an opportunity to show what is possible with persistence. They hired a local solar company, Independent Power Systems, who designed and installed a grid-connected, fully off-grid-capable power system, with backup battery storage, that enabled them to cover their home’s entire energy consumption and provide excess energy to the grid to support their neighbors after thinning some of their tree-cover. The project also conserved resources by using a previously developed site, local materials, and tree-thinning materials to provide nutrients for the plant beds on the site.
Despite David and Emily’s many challenges, they transformed an old, unsustainable, energy-hog house into a self-sustaining home by being persistent and finding the best people to trust to help them achieve their goals. David wanted to prove what is possible with just a normal home and show that everyone can do something like this. Old, unsustainable homes exist all over the country with the potential to be transformed. He proved that it’s not necessary to spend a lot of money to buy or build a new to live in a sustainable home.
