Residence for Florence
and William Tsui
Berkeley, California USA
Owners: Florence Tsui
Location: 2747 Matthews St., Berkeley, California USA
Date: 1993-1995 (Design and construction)
Total Cost: $250,000.00
Square Footage: 2000 square feet
This structure is based upon the world's most indestructable
living creature--the Tardigrade, with its oval plan and parabolic top
it utilizes the same structural principles nature employs in creating
an astoundingly durable design. Internationally touted as the world's
safest house it features an oval reinforced concrete foundation over
a series of large perforated drain pipes that immediately dispel any
water built up and heaving from the soil or sudden flood conditions.
Water is immediately taken out through a large storm drain. The house
is partially buried in the soil about 1.5 meters and the walls are made
of recycled styrofoam and cement block called "Rastrablock". It is impervious
to water, fire, termites, has a 40+ R-Value rating and reduces sound
by 50 decibels. It is also 10% less expensive then conventional framing
construction and much less labor intensive since the blocks are simply
glued together, rebar placed inside and concrete poured in. The upper
structure is a series of parabolic arches connected by stressed wood
sheathing and sprayed with reinforced concrete tied into the recycled
block system creating a continuous, unified shell. A series of black
flex tubing is placed on the roof to act as passive solar warm air vents.
The house has proven itself to be cool in the hot summer months and
warm in the cold winter months, all without mechanical air conditioning
and heating machinery. A 5 meter diameter south-facing window acts as
a light and heat (winter) magnifier to provide light to the central
10 meter high rotunda living area. From this open rotunda light and
heat is distributed to the rooms of the house at two levels. Inside,
the house contains three ever-deepening levels at the ground floor.
The house grows more spacious the deeper one walks into it. The core
living area features a suspended spiral ramp with steel cables radiating
from the roof skylight. The 220+ square meter house contains a living/conversation
area, a recreation room, music/study room, laundry, kitchen and antique
display area, three bathrooms, three bedrooms, continuous hallway cabinets,
sunken outdoor patio and garden. All but three of the windows in the
entire house are openable. All shelves and cabinets are built into the
structure of the house and cannot be broken apart in an earthquake.
All forms are curvilinear for safety and ease of passing. Every part
of the house is interconnected structurally with every other part of
the house. The structure disperses stresses and strains that act upon
it unilaterally. Manually operated opening and closing "Nostril" windows
let in fresh air without letting in insects. Its aerodynamic shape also
prevents fire, carried by wind, from adhering to its surface, helping
to prevent fire.
Construction Materials: Concrete, styrofoam/cement
block, "Hardwall" structural plaster, Stucco, Non-toxic waterproofing,
acrylic, marine fiberglass, douglas fir, recycled wood, birch veneer
plywood, "Opalina" irridescent paint and rich gold exterior paint
Special Features: The house is a precise ellipse in plan and
contains four bedrooms, three bathrooms, a circular living room, sunken
outdoor patio and carport. The two story structure utilizes a unique
system of recycled styrofoam and cement blocks reinforced with steel
and concrete. This material called, Ener-grid Block, is lightweight,
fireproof, waterproof, termite-proof and extremely earthquake resistent.
Structurally the block creates a reinforced lattice structure, very
much like the skeleton of the Cholla cactus. Stress and strain forces
are distributed equally throughout the lattice network. The continuous
elipse wall forms an extremely durable shell chosen because of its properties
of lateral rigidity.
Foundation consisting of Ener-grid recycled styrene/cement
The walls of the house are angled inward at 4 degrees to create a compressive
structure with a low center of gravity; further aiding in resistence
to lateral turn-over forces produced by strong earthquakes. This approach
to structure has proved to be superior to the box configurations that
is typical of buildings of the past. The curvilinear continuity of the
ellipsoid form distributes loads in a dispersed manner tangent to the
surface, thereby preventing point loads which are potentially destructive
to the structure as a whole. This approach to structural integrity increases
the internal strength of the frame while minimizing the surface area.
By contrast, the box frame is poor at negotiating point loads because
it needs supplementary reinforcing to resist tangential forces. In addition,
the joints are at greatest risk because stress and strain forces stagnate
at the corners requiring further rigidification and bracing to prevent
the natural tendency to skew.
Construction of the circular ramp using douglas fir
Another advantage of the Tsui house design is that the exterior walls,
being curved, deflect and accelerate wind currents around the surface
preventing the vacuum suction phenomenon, so prevalent in flat plane
surfaces, from occuring. The dimpled surface further enhances the efficiency
of the aerodynamic shape by relieving wind friction. One of the most
pronounced dangers of flat surface buildings are their ability to draw
fire to themselves. Flat planes are fire targets in a high-risk fire
area where winds are unpredictable. When a flame-carrying breeze contacts
a flat surface it creates a small vacuum on that surface. This vacuum
sucks fire onto the wall and accelerates the process of flame spread.
By curving the walls, as in this design, this vacuum effect cannot occur
and winds and flames are taken away from the surface helping to prevent
flame build-up. For the Tsui house design an additional ring of four
water jets immerse the exterior of the house in the event of a neighborhood
fire. This precaution renders the house virtually fire-proof from the
The placement of sub-surface tubes are used to create
a self-sufficient radiant heating system.
The design program approached the house as a living organism capable
of actively responding to various natural elements of the site. A prominent
example of this is the subsurface solar water tubes that are positioned
to correspond to the sun-ray like exterior motif that covers much of
the upper level of the house. Water in the black tubes is heated by
the sun throughout the day. At night the stored heat is radiated back
into interior of the house walls and provides radiant wall heat. This
subsurface solar heating system was conceived by studying the bone and
capillary structures of two dinosaurs, the Dimetradon and the Stegosaurus.
Both reptiles utilized a form of biological solar heating by way of
the large sail-like structure on the back of the Dimetradon and the
series of plate structures on the back of the Stegosaurus. In both these
ancient reptiles the plate structures were surrounded by a very packed
configuration of blood veins. The sun heated up these veinfilled plates
and helped to regulate the body temperature of these reptiles. Thus
a form of living solar heating was being practiced 150,000,000 years
The continuous curvilinear form of the building maximizes the capacity
of the exterior surfaces to drain away water, particularly when the
exterior jet sprinklers are activated. For this and other reasons the
house contains no eaves, soffits, shingles and related architectural
features common to traditional buildings. Waterproof sealant is used
both as an admixture to the cement plaster exterior as well as separate
surface coating. The styrofoam/cement blocks render the house impervious
View of the central sitting area, and circular ramp.
On the interior there exists no stairs--the multiple levels inside the
building are reached by a series of ramps which culminate in a central
circular ramp at the midpoint of the house, figure 10. The name of the
house "Ojo Del Sol" (The sun's eye) or Tai Yang Yen, in chinese, comes
from the eye-like "oculus" window, fifteen feet in diameter, facing
south, which disperses sunlight inside the house and warms the floors
surface. In the daytime the floor absorbs this solar heat. At night
it radiates into the spaces within.
The circular "oculus" window on the south-side of the
building disperses sunlight into the house to warm the floor surface.
The ground level is three feet below grade to make insulation more effective.
Three levels divide the ground floor into three living zones. The upper
floor level features a series of specially designed trusses modeled
after seagull bone marrow. The challenge here was to create an overhead
truss system that minimized material usage, was extremely lightweight
for ease of transporting and placement, and was very strong. In nature,
an ideal candidate for fulfilling these requirements was the seagull
bone. The bone is comprised of a series of angled struts integrated
to the bone surface from bottom to top. By minimizing the number of
struts and open space the seagull bone becomes a wonder of natural engineering.
By understanding the principle at work in the bone we are able to solve
the problem of material/weight efficiency without having to resort to
the convenient but inefficient use of premanufactured beams and struts.
View of the central sky-light above the circular ramp
Owner Requirements: Maximize the usable square footage of the
lot (35 feet wide by 100 feet long with a 28 foot height restriction).
No stairs. Four bedrooms. Three bathrooms. A place to park a car. Privacy
from neighbors. Lots of light. Conserve heatings and cooling bills wherever
possible. Absolutely waterproof foundation. Minimize or eliminate grass
areas. Fans in all bathrooms. A place to display art items. Do not go
over budget. Spaces open to one another.
View of the bas wall relief in the master bedroom
Ecological Requirements: None. The owners were gradually educated
about the benefits and advantages of a nature-based, ecological approach
to designing their home. They grew to support this ecological attitude
especially if it meant a cost savings and a simper way of maintaining