With
a strong susourtainable imperative and a modest budget, BMW Designworks/USA commissioned
the retrofit of their offices near Los Angeles. Recognizing the constraints of
the existing tilt-up concrete box building, Daly Genik Architects introduced two
courtyards to bring light, air, and views into the large building footprint. The
resulting spaces are concentrically organized around these "oases." Open workstations
and break-out areas are located adjacent to the courtyards while offices or conference
rooms with increased visual and acoustic privacy are distributed around the perimeter
of the existing building. Our interpretation of Daly Genik's design in
a sustainable context was instrumental to BMW's acceptance of the scheme, and
it signaled directions for the design's further development. We highlighted five
major opportunities inherent to the design that could be further exploited to
enhance its sustainability: daylight and views, fresh air and ventilation, night
cooling, rainwater management, and a green roof. Our discussions and analysis
recognized the enormous potential of the courtyards, in particular, to perform
in various ways. First and foremost, coupled with the existing twenty foot
ceiling height, the courtyards and open work stations afforded the potential to
daylight most of the building. Daylighting reduces the need for ambient electrical
lighting throughout most of the buildings and replaces daytime task lighting in
the work spaces on the courtyard edge. The high floor to ceiling height also means
that the fully-glazed courtyard enclosures can allow light to penetrate deep into
the office spaces. Large overhanging canopies positioned above the open work stations
are clad in reflective materials. These function as light shelves to bounce daylight
onto the ceiling. Exterior shading devices on appropriate orientations also accomplish
this, while minimizing heat gain from direct beam solar radiation. For the workstations
immediately adjacent to the courtyards, view glass with operable blinds or shades
maximize user control and visual comfort. To assist building ventilation
and fresh air intake we recommended that operable windows or louvers be incorporated
into the courtyard's curtain walls. Particularly in this relatively benign climate,
the building can be "opened" for much of the year, improving employee comfort
while reducing energy loads on mechanical systems. With the high thermal mass
provided by the exposed concrete walls and floor slab, there is also the potential
to cool the space for much of the year using night-time ventilation. Landscaped
courtyards can also be used to manage rainwater. By draining the large area of
the roofs into the courtyards, rainwater percolates slowly into the ground thereby
reducing runoff. Alternatively, rainwater can be stored in cisterns and used to
irrigate the grounds throughout the year. Finally, the application of a green
roof will reduce solar heat gain by increasing roof insulation while shading it
and evaporatively cooling the air around it. The green roof is especially responsive
to the environmental imperative because it mitigates runoff by retaining storm
water and provides a habitat for birds. In spite of its relatively modest
size and budget, this project has the potential to incorporate many of the sustainable
strategies often thought of as expensive and complex. Estimated at a preliminary
cost of under $75/sf, BMW Designworks/USA illustrates how, if sustainable thinking
can be incorporated from a project's outset, fiscal and environmental responsibility
are not necessarily mutually exclusive. | 
