Napa Valley Hotel
This hotel near Napa Valley is designed to appeal to eco-tourists. The
design is based on a courtyard to create an oasis in the relatively hot
climate, turning inwards to an artificial lagoon and swimming pool. Most
of the 140 guest rooms are raised on a second-floor plinth and accessed
via a double-loaded, clerestory-lit corridor. Public areas such as lobby,
restaurant, and conference rooms occupy much of the ground floor, in addition
to service-oriented spaces such as the kitchen, laundry, and staff offices.
The hotel developer established a strong environmental imperative from
the project's genesis. The design team was assembled with the understanding
that the project would emphasize the symbiosis of human and natural relationships.
Architects, engineers, and consultants with expertise in permaculture,
water management, recycled and sustainable materials, alternative energy
sources, passive solar design, energy efficiency, thermal comfort and
daylighting were invited to collaborate in the project. Currently the
developers have their sights on achieving a LEED Platinum rating.
We have consulted on a wide range of issues including: climate analysis,
building envelope, material assemblies, daylighting and shading, conditioning
systems, material specification, alternative energy sources, and energy
efficiency. We are responsible for sizing, specifying and coordinating
the design and economics of the significant photovoltaic array as well
as for the LEED certification process. All of the consulting has been
closely coordinated with the architect, landscape architect, engineers,
and other consultants.
The climate at American Canyon is prone to long periods of high temperatures
so keeping hotel guests cool is a challenge. The building envelope is
well-insulated and window apertures effectively shaded, particularly to
the west and south. A green roof is designed to provide additional insulation,
shading, and evaporative cooling. Windows are specified to incorporate
spectrally selective glass with low U-values and shading coefficients.
Interior partitions consist of two layers of sheetrock for increased thermal
mass and acoustic isolation. Finally, the concrete floor slab will be
cooled by night ventilation supplemented by an in-floor chilled hydronic
During cool times of the year, the hotel will be passively heated by
direct solar radiation. The high thermal mass of the floor and partitions
will absorb some of this heat and re-radiate it during the evening. On
overcast, or cold days, active thermal conditioning will be supplied by
radiant hydronic heating embedded in the floor slab. In addition to this
system's energy efficiency, it is particularly appropriate for a hotel
because it provides the highest degree of occupant comfort while producing
Daylighting and shading was another area of concern, as we sought to
maximize visual comfort while minimizing the use of electric lighting.
In the double-loaded corridors this was achieved by introducing a continuous
clerestory that wraps around all four wings of the hotel. The guest rooms,
which are side-lit, use high performance glass to reduce contrast between
outside and inside. Vine-covered trellises shade the clerestory to modulate
views of the bright sky and protect the rooms from excess solar radiation.
Effective daylighting is coupled with various strategies to reduce electric
loads, including key-slot activated lighting controls and reduced number
of electrical lights and outlets.
Other measures include solar electric and solar hot water. Panels are
sized and priced based on calculated electrical and hot water demands.
We have also coordinated the selection of alternative energy sources based
on state tax credits, incentives, and power company buy-back options.
An interesting aspect of this project has been working with the client
to coordinate the energy efficient and ecologically responsive aspects
of the design with the unique experiential qualities of a resort hotel
environment. Imagining a guest's perspective in the eco-hotel, we have
helped the design to emphasize sensual elements which also play an environmental
role, such as the smell of vines on trellises, the sound of chirping birds
on the green roof, and the cool comfort of a concrete floor and cool walls
on a hot summer day.