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Korie Edises Residence
Hillsborough, California


Ms. Korie Edises, owner of the house at 45 Berryessa Way, wishes to build a second unit residence on her property. The existing house contains 3600 square feet of space. The second unit contains 1200 square feet of space. Ms. Edises plans to rent her existing house and live permanently in the second unit residence. The existing house is of unusual design and the second unit residence design is fully in keeping with the unusual nature of the existing house as required by the City of Hillsborough Planning regulations.

The second unit residence has many structural and ecological features developed to accommodate the climatic, environmental and programmatic needs of its owner. It is a model of self sustainability and indigenous materials applied in uncommon but highly functional ways creating a self-sustaining design that is a fine work of art as required by the owner.

Poetically speaking, the unit is like a swirling cloud formation soaring over the hillside with areas that create a peek-a-boo experience of light and shadow. Circling tubes of copper spin below the windows to relate the unit to its golden grassy surroundings. The house sits lightly on the earth. The north patio leads the onlooker to the groves of trees beyond and beside the house—nature and humanity together as mutual partners in a living environment full of change and wonder, mystery and exuberance.



LOCATION: The 1200 square foot unit is located approximately half way down the hill from the existing house. It cannot be seen from Berryessa Way and is situated among the large oak tree groves to the south of the existing house.

ENTRANCE: The house features two entrances at the north side; a private entrance, over a walkway bridge, directly to the second level bedroom area; and the main entrance, through a metal gate flanked by 4 foot high stone planters leading to an open patio area bordered by a waterfall and water catch pond. Ground level living and kitchen areas are accessed from this entrance patio.

CELLAR/COLD AIR SINK: This underground level acts as the structural base of the unit from which the ground and second levels are rooted. It also acts as the fundamental cooling system for the unit. The cylindrical structure of the ground and second levels sit firmly on the support walls of the cellar creating a hollow pad which provides stability in an earthquake. This pad is connected to the outdoor patio above, at ground level, which adds to the stability of the overall structure by gripping the ground surface.

LEVEL ONE: This is the living and kitchen area with a fireplace and spiral stair leading down to the cold air sink/cellar, and up to the bedroom and bathroom level. 8 foot high triangular windows open out onto the south east, south and west hillside and panoramic views beyond. Floors are made of quartzite flagstone over radiant heated concrete. Total square footage: 800 square feet.

LEVEL TWO: Contains the master bedroom and bathroom with three closets. 8 foot high glass doors open onto an outdoor patio which contains a fireplace and seating around the patio parapets. Total square footage: 400 square feet.

STRUCTURE: The cellar acts as a stable platform from which sits the upper levels giving it a stable base able to resist overturn by earthquake forces. The round level patio, cellar structure and upper floors are unified structurally to act in unison during an earthquake. There are no points or joints to break apart—the structure is connected as one continuous unit. The ground level support cylinder forms a dendriform column at its base attached to the south end of the cellar structure to minimize the footprint of the building.

EXTERIOR FINISHES: The main house structure walls are glass tiles over spray-on concrete monolithic walls. The sun visor/wind cowl is galvanized sheet metal with an iron oxide finish protected with a clear UV protectant guaranteed for 20 years. All exterior patio floors are quartzite flagstone acquired locally. The entire unit is made from indigenous materials found within the immediate area. The areas below the windows are wrapped in circular layers of treated copper tubing ¼ inch in diameter creating swirls of light that visually connect with the golden grassy earth just below.


The house will be constructed of “Insteel” prefabricated spray-on concrete panels, a monolithic concrete panel system that has proven itself undamaged in 7.0+ Richter scale earthquakes, extreme fire conditions, major flooding and hurricane level wind conditions throughout the USA and in other countries. It is 10% less expensive than wood frame construction and extremely energy efficient in insulation and labor saving value. This concrete system is also in-keeping with the concrete structure of the existing house. The cylindrical geometry of the second unit allows for great aerodynamic characteristics which support ease of cooling the house and make the house much less prone to fire. It is also a geometry that is very stable in resisting earthquake stresses and strains.


The second unit’s geometry allows for the easy flow of uphill and lateral wind currents that that are constantly active on the site. Breezes flow around the circular geometry and accelerate in smaller, more confined spots such as through the windows and curving sun visor cowls, letting the house cool itself by natural breeze and plentiful sun awnings. The house is surrounded by a swirling, heaving metal sun visor that also acts as a wind cowl to direct breezes through openings that contain small windmills for electricity production. The climate is breezy and hot during the spring, summer and fall months and breezy and cool during the winter. Natural breezes are maximized for cooling during most of the year.

The unit also contains a cellar which acts as a cold air source (59 to 61 F degrees constant year round) from which cool air travels upwards through vents in the floors and within the spiral stair cylinder. The cold air naturally rises and helps to cool the entire house. Most of the windows of the unit open and close and act as cross ventilation louvers.

A waterfall under the foot bridge at the north side of the unit acts as a natural outdoor air conditioning system by providing active, cool, moist air over the north patio end of the house creating a comfortable envelop of moving air—a very desirable condition to have in this hot, dry climate. This allows the outdoor patio/sitting area and the main entrance of the house to be cool, inviting and pleasant. The waterfall flows down into a long, outdoor catch pond which recycles gray water from the unit and oxygenates the water as it falls into the pond, cleaning the water in the process. The sweeping sun visors of the unit and the house itself keep the north patio in shade and protect from rain in the winter months.


The second unit features the placement of four windmills located within the curving forms of the sun visor/wind cowl structure. Natural breeze is funneled and accelerated through the cowls and directed past the windmill arms causing them to spin and creating electricity to the house. The undulating, swirling wind cowl forms are crucial to the dependable functioning of the windmills, to sun control and to the general cooling effect in and around the unit.

A cantilevered metal pipe at the west side of the unit contains a series of suspended 2 foot by 4 foot photovoltaic panels that are naturally inclined at 45 degrees to maximize solar exposure to them. These panels produce electricity from sunlight which is then used within the residence unit. The combined electrical output of the windmills and photovoltaic panels are more than sufficient to power the entire unit. Storage batteries are contained in the cellar area.


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