LAND AS THE RESOURCE - Low Impact Development and Sustainable Stormwater Management - page 74

from their staff, consultants, or design professionals. In practice, the energy source
can be situated remotely or on site, as long as it does not use fossil fuels.
The zero net water use is of primary interest here, in that it must go a step
beyond the concepts of LID presented in this topic and consider the impact and
use of water through the entire hydrologic cycle. The challenge is to design a
building that can meet the daily demand for fresh, potable water, recycle the
resulting effluent within the building design for nonpotable uses or recharge the
soil mantle, and capture the rainfall as the primary water source if groundwater
sources are inadequate. If an external water supply is used, the issue is how to
return this supply to the natural environment rather than to a sewer.
Applying the concept of zero net water use to new site designs begins with the
question of whether or not public water (and sewer) is available. This is a prime
determinant for most new land development projects and greatly simplifies the
regulatory aspects of land development, not to mention the capital investment in
infrastructure. Following the Living Building Challenge, however, the availability
of municipal water and sewer services would not be a key consideration in the
site selection process, and actually might present difficulties.
In an existing urban or suburban environment, the redevelopment of a parcel
and new structure that meets the Living Building Challenge becomes complex,
since the water and sewer service is long established, and any disconnection
from this plumbing might present financial and regulatory problems for the
developer. The public investment in existing infrastructure requires that any
new development help to underwrite the operating cost of such systems, and if
new development is allowed to “opt out” of the public systems, the long-term
implications of new construction could be negative for the community as a
whole. This is especially true for older cities that have gone through the cycle
of decline and rebirth, which would hope to encourage redevelopment by the
availability of such infrastructure.
In Pittsburgh, Pennsylvania, an existing complex of buildings, situated on a
central hilltop, has been a major cultural asset to the community for over a cen-
tury. Known as the Phipps Conservatory (Figure 3-20), this Victorian arboretum
occupies over 13 acres, with the original glass conservatory buildings comple-
mented by recent (2005) construction of a tropical rainforest building and large
greenhouses for growing vegetation, as well as a meeting room and food service
area. In 2008, Phipps decided to add an additional structure to the complex in
a rear location that was in city ownership and used largely for vehicle service
and materials storage. This building was to function as the Center for Sustain-
able Landscapes, and the goal was set to made it a living building, the first in
Pennsylvania and possibly in the eastern United States. It was hoped that this
center would develop and teach the cultivation methods and plant materials for
sustainable landscapes, with little or no use of irrigation or of chemical pesticides
or herbicides that would serve urban environments into the twenty-first century.
The goal of meeting the Living Building Challenge influenced every aspect of
the design, and for over two years a team of architects, engineers, planners, and