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King Pine Homes purchased the Broad Cove property in late March 2014. Sitting vacant all winter, this home was in need of a complete remodel. However, it had "good bones" and we saw potential for this 1960's garrison located in a seaside neighborhood of Cape Elizabeth, ME. At the time of purchase, the home had 3 bedrooms, 1.5 baths and 1400 sq. ft. of living space. Most of the home's features were original with the exception of a serviceable boiler installed circa 2000.
The remodel plans called for converting the basement into an additional 600 sq. ft. of living space (a man cave, office space, or play room), developing a new master bath, as well as building a front porch and back deck. Since we were going to be touching almost every surface in this home, we felt it was a good candidate for a home energy retrofit as part of the remodel process.
Prior to beginning demolition, we had Chris Larson of Rook Energy Solutions perform an energy audit. Not only did we want to establish a baseline reading to evaluate our performance later on, but we also wanted to find out where this home was wasting energy.
Test-In Blower Door Reading & Energy Audit
A blower door is a tool used to measure the air tightness of a home. The initial blower door test on this project registered at 2630 cubic feet per minute (CFM) at 50 pascal (pressure metric), which is consistent with many of the other homes in neighborhood. Constructed during a time when energy efficiency wasn't a priority among developers, this building envelope offered ample room for improvement.
The energy sinks identified by Rook Energy Solutions were insufficient insulation in the basement and attic along with a leaky building envelope. During the planning phase of this remodel, we integrated the home energy efficiency upgrades recommended by Rook Energy Solutions' energy audit report, which included:
Installing rigid foam insulation, spray foam insulation, and blown-in cellulose insulation in the basement, walls, and attic;
Air sealing with spray foam and tapes;
Optimizing the boiler with smart controls;
Removing the tankless coil from the boiler and installing an independent hot water heater;
Adding an extra zone to the heating system;
Building an airlock entryway in the garage;
Removing old windows and doors and replacing them with energy efficient models; and
Addressing moisture/water issues in basement by regrading the back yard, installing exterior drains and gutters, and designing wall assemblies to prevent condensation.
Test-Out Blower Door Reading
Once the drywall was installed and the insulation in place, we conducted a second blower door test. It measured 1065 CFM at 51.6 pascal, which represents a 60.5% reduction in air leakage. Tim Ingraham modeled the retrofitted home, estimating an annual fuel savings of 60 to 75%, or $2000 to $3000 per year.
Incremental Cost of the Energy Efficient Remodel
At King Pine Homes, we're interested in identifying the incremental costs associated with an energy efficient remodel. We're attempting to answer an important question: How much extra does it cost to improve energy efficiency during a whole house remodel?
Obviously, the answer to this question depends on how many upgrades you make during the retrofit process. Achieving Passive House standards was not in the budget for the Broad Cove project, but we still wanted to make a meaningful impact on comfort, indoor air quality, and monthly savings of the home. I'd spoken with Chris Larson about the "pretty good house" concept, which attempts to strike a balance between retrofit costs and actual energy savings. Given our overall project improvement budget of $90,000 and schedule of 90 days, we thought a 40 - 50% reduction in energy usage would be both obtainable and affordable.
In the end, we spent $13,000 over and above what we would have otherwise spent on the remodel. The results were great, as we surpassed our target energy goal by a long shot. Here's how the "retrofit" dollars were spent:
$10,000 - Air sealing and insulation (excluding $1000 rebate);
$1,250 - Windows and doors;
$650 - Smart controls for the boiler;
$550 - Insulated electric water heater;
$200 - Bathroom exhaust fans; and
$350 - Kitchen appliances.
Again, these figures do not reflect the full cost of the products we used, just the marginal increase in cost associated with buying energy efficient models. For example, you might purchase an EnergyStar certified electric water heater for $1200 whereas a comparable stock model costs somewhere around $530. Thus, the marginal cost of purchasing the energy efficient option is $670, which is allocated to the retrofit budget.
Indoor Air Quality & Energy Efficiency
Since we were tightening up the building envelope at the Broad Cove project, we needed to be mindful of indoor air quality (IAQ). A significant portion of the $90,000 budget was allocated to moisture management and having asbestos floor tiles professionally abated from the basement. Although not directly impacting the efficiency of the Broad Cove home, IAQ is a tenet of home performance. For example, excess moisture will compromise the integrity of the insulation, not to mention the health concerns associated with mold. Thus, we did jobs like regrading the slope of the back yard, added exterior drainage, installed bathroom exhaust fans, and designed wall assemblies to prevent condensation. In the end, we can't say the money spent was just for "efficiency" purposes, but we can say it contributed to a far superior home.