Tom’s Marshall Home

ABOUT THE HOUSE: This bayside home on Tomales Bay was once an old, very rustic one-room cottage with a tiny bathroom. It was brought up to date with a 2-story addition built to Passive House standards and other green home improvements.

ENERGY EFFICIENCY:

• Strong durable weatherstripping was installed around all doors for good air sealing.  

• Leak sealing: in the old shiplap siding, there were cracks at seams and considerable potential for air and moisture penetration.

• Insulation: in the old part of the cottage, the wood wall paneling was removed and set aside. Then any additional penetrations, which could be identified by light coming in were also sealed with caulk. Next fiberglass batt insulation was installed and then a vapor barrier was installed on the inside. Next the original wood paneling was put back in place.

• Single-paned windows were replaced with double pane and all the edges around the windows were sealed with caulk. Then a new yet classic trim was placed to cover the window edges.

• Old, low acoustic tile ceiling was removed to open up the space up above. This facilitated adding larger roof beams and access to fully insulate inside the roof joists. Then new pine ceiling paneling was installed inside over the new interior insulation.

• 2x6 framing was used on the addition to provide plenty of insulation space.

• The opening for the spiral staircase facilitates heat rising from the thermal mass to the upstairs bedroom, which is a nice feature for cold nights. Conversely, when you want to cool things off, windows which can be opened from 3 sides of the upstairs bedroom can quickly provide cross ventilation with ocean air.

• A passive solar design was developed for the addition where all features were optimized for energy efficiency and comfort.  The new double pane windows were sized and orientated for optimal solar heat gain while also taking advantage of the view.  To absorb solar heat gain during sunlight hours and then radiate it out to the living space in the evening, thermal mass was included in the new construction. This thermal mass, to absorb the solar gain and then radiate it to the living space in the evening, was sized and employed by a combination of concrete and tile floor.

• Rooftop solar

• Double pane skylight

• Since heat rises, the overhead ceiling is generally the highest priority for having adequate insulation or R-value.  So given that the roof also needed to be replaced, we took the opportunity to also install rigid foam insulation on top of the roof deck and then a plywood layer above that, before installing the new roof. This rigid insulation is now sandwhiched in between the original roof and the plywood with asphalt shingles on top. This is all enclosed inside the wide wood trim.

ELECTRIFICATION:

• Electric induction stove

• Replaced gas-heated hot tub with a newer electric one.

• The first electric appliance improvement was to replace the old propane stove with this electric induction stove, which has performed very well for 5 years now.

• Ductless mini-split heat pump in living room heats whole 1000 sq ft cottage.

• Electric Vehicle and charging

• Gas fireplace replaced with electric fireplace, which provides ambiance and some added heat if you choose.    

LANDSCAPE:

• Drought-tolerant native plants minimize water use and support local insect and bird pollinators.

SUSTAINABLE MATERIALS:

• Old redwood shiplap siding from a torn down old San Francisco Victorian was cleaned up and used on the addition, which pretty well matched that of the original cottage. Also old maple flooring from a prior demolished gym was used to recycle old wood (with plenty of character) as much as possible.