Green Remodeling Entire House
Passive Solar Upgrade & Japanese Style Living Room
The client was looking for simple energy efficiency improvements with the greatest possible gain. The first steps to improving this property included installing insulation to the exterior of the house, using passive solar heating and cooling concepts, and implementing heat recovery ventilation technology. The international couple, husband from Switzerland and wife from Japan, also wanted their home to include build features from their native countries. The pattern on the shutters has a very Asian look and its accompanying hardware was imported directly from Switzerland. The EIFS is a popular European exterior cladding system and was easy to apply onto the brick. Their new living room was built with a heated sunken floor and Japanese Kotatsu table.
Following the completion of the remodel, the client’s winter heating bill decreased from $380 to $80. Drafts and cold spots were completely eliminated. On a cold January day, with the outside temperature in the 30°s, the temperature in the house will rise from 68° to 75°F with the heat turned off. The Japanese style living room with heated floors has become the client’s favorite family gathering place where their children love to hide under the table and watch cartoons. The large window adjacent to the living room is a great place for the family to relax, read a book, and observe the wildlife in the forest down below.
With the intention of connecting to nature, the kitchen was moved to the front of the house so the new large south-facing windows could be a part of the living room. The family of seven needed a bigger kitchen with more countertops and cabinetry. Their new space features two kitchen sinks, an induction range, LED under cabinet lights, and LED track lighting.
The custom built table, featured in the Japanese style living room, was made from Plyboo and Kirei boards. Plyboo is made from 100% bamboo and the Kirei boards are manufactured from sorghum straw with no-added-formaldehyde adhesive. To heat the area around the table, we used Flextherm heating mats. These heating mats were embedded into self-leveling thinset on top of 1/2” HardieBacker boards. To renew the balcony, we decided to install a walk-able roofing membrane on top of slightly sloped plywood and we upgraded the railings with bamboo found in the forest nearby.
The custom Japanese style shutters were built with natural untreated cedar. These thermal shutters accompany most windows throughout the house. White stucco finishes are commonly seen in Japan and Europe, which is why it seemed like a good fit for the exterior portion of the design. The gable style roof with the small overhangs is themed after traditional Japanese construction.
Many older buildings on the eastern part of the US are true masonry structures, meaning they have bricks on the exterior and CMU blocks on the interior with no insulation between them. These homes are hard to heat and fairly easy to cool. For this reason, a decision was made to install 5” polystyrene foam covering the brick and finishing it with (EIFS) exterior insulation finishing system. With all the stone moved to the interior of the thermal envelope, it began to act as thermal mass, making it easier to keep the house steady at a comfortable temperature. This in fact turned out to be true. Mechanical heating and cooling has now only become necessary in extreme temperatures.
Early on in the design process, the homeowner fell in love with the idea of installing shutters, the way they are still used in Switzerland today. The plan was to upgrade them so they would not only be decorative but also remain fully functional to seal the house air-tight. That turned out to be a challenge since the necessary hardware could not be found on this side of the Atlantic. They needed to be imported all the way from Switzerland. Because the shutters are large and heavy, they needed to be bolted to the structure before the insulation foam boards went up. This may be the very first house in this area remodeled with workable shutters that not only close, but are air tight and improve R-value.
Why Thermal Shutters?
Upgrading a true masonry house with passive solar is something new and no research data or experience was documented anywhere. Calculating the right size of south-facing glazing was kind of a hit or miss. We ended up using 8% of south-facing glazing of the total amount of square footage, which turned out to be just right. The house does not overheat in the winter mainly because of the masonry walls.
To reduce costs, the large south-facing openings were perfectly aligned so that the upper ones were above the lower ones. After shoring the structure, all the brick was removed from top to bottom and new posts and LVL beams were put into their place. To add more square footage, the existing floor joists were sistered to cantilever 3 ft. past the existing footprint. This new 3 ft. wide space is now accommodating a large window seat, which has become a family favorite as it creates the ultimate connection between the interior and exterior.
The homeowners felt like they were in the perfect position to use traditional time-tested building methods and improve them with modern building science. His connection to old style European construction inspired him to use shutters that aesthetically improve the house but also significantly save energy. Installing EIFS over the brick turned out to be a huge success. Not only is the house warmer, but it’s also quieter and easier to heat and cool. The added heat recovery ventilator makes the house healthier as it pulls old stale air out of the bathrooms and kitchen and adds new fresh air into the bedrooms and living room. The south-facing windows fill the house with sunlight and moonlight which they love. The traditional Japanese living room is a favorite gathering place for the family, but also helps reduce heating costs. The heated floors surrounding the table encourages family members to spend time there and don’t mind if the bedrooms are set at a lower temperature.