"Environmental and Economic Balance"
Mustang Island Episcopal Adult Conference Center and Youth Ecology Camp
"Is it possible to build in an environmentally responsible manner on a barrier island?"
This study outlines the unique environmental challenges posed by a South Texas barrier island site, considers the typology of existing nearby developments, researches appropriate building materials and technologies, and poses a new model for barrier island development with particular attention to preservation of the sea grasses and habitats which proliferate in the zones allowable for development behind dune line.
The Mustang Island Episcopal Adult Conference Center and Youth Ecology Camp is a $7m phased, in-progress project whose functional requirements include recreational, residential, educational, spiritual, and environmental design components. The owner is the Episcopal Diocese of West Texas and the project is in a design development and fundraising phase.
The 23.5 acre project site is located on Mustang Island Texas, ten miles south of Port Aransas within a sparsely developed broad zone of land privately held, but fully available and intended for development. In spite of dune and wetlands protection ordinances, projects to date have tended to do battle with nature, tilting with the windmill of this harsh, beautiful place by making hard but tenuous edges with the natural land. The nature of these edges is a central focus of this paper. Unrelenting sea breezes and fine sand make this one of the most corrosive coastal environments in the U.S.
Existing Developments and "Edges"
Before commercial development, the island shows few clues as to property edges. Public and private properties flow into each other forming a seamless sea of natural grasses and sand dunes. At one scale there is huge expanse and endless vistas, and at another there is incredible ecological variety and distinct zones and places. There are the beach, the dunes, the grasslands, the wetlands, and the inland bay shoreline, but between, the boundaries, if any, are soft, organic and dynamic. As residential and commercial developments have begun to redefine large segments of the barrier island, hard and arbitrary edges become drawn. Noticeably, smaller developments (by nature of their scale, not their intent) are often more organic and leave more land untouched. Still that line beyond which the ground is left entirely to nature is a relentless battleground - claimed, reclaimed and then claimed again - a micro-war of irrigated sod and lawn mowers against sand and sea oats. Many of the larger and higher density projects seem to have tried to completely remake the land, drawing edges and shapes similar to those of the landlocked city blocks. Here the automobile as well has become a major defining element within the modified landscape. Conventional parking solutions require substantial areas of paved hard surfaces which often consumes a significant portions of the site. But constant sand accretions on to parking lots and tennis courts are a reminder that this is borrowed land which can only be well or long used with particular care and consciousness. The beauty of the native plants and habitats of the barrier island can be further compromised by the emphasis placed on the beach front and water views. Such emphasis has often placed buildings within the most dynamic and vulnerable zones of the barrier island creating an uneasy existence. There remains a sense that developments by trying to tame the land have created an unhappy and unrelenting struggle. If we can find a way to build firmly but flexibly; if architecture can sit lightly on the land and bend to the forces about it, then it can contribute to the beauty of the island instead of degrading it.
Research was undertaken in these areas:
building systems and technologies
construction staging / site impact
site environment and context
indigenous plant life
indigenous animal life
solar orientation, breezes, vistas
Key issues and strategic objectives were identified in each of these categories prior to schematic design. A materials palette, key details, a siting strategy, and an environmental program was developed.
Key Observations and Concepts
The design challenges posed by this site in a very real sense have more in common with the architecture of offshore drilling platforms ten miles to the east than with conventional buildings ten miles to the west. In this dynamic landscape, a building should attempt to alter the ground only as a ship would part waters - in fact in this place, there is little long term hope to do more. A building should embody the discipline of environmental responsibility in its structure and its daily activities.
Strategic elements include:
A repetitive building typology whose expressed materials, structures, and details are a direct and simple derivative of the site. A compact foot print that concentrates parking and outdoor activities in the areas below buildings where shade otherwise destabilizes natural vegetation. Permeable parking surfaces that both accept and stabilize sand accretions, and edge structures that create a 'freeboard' to the ground and grasses.
Buildings elevated for tidal flooding and braced for 150 mph winds. Low profile buildings that are scaled and linked so as to respond to the topography, facilitate phasing and create habitable exterior spaces.
Elevated boardwalks to allow small animal habitat and migration. Extensive corrosion resistant detailing.
Visitors arrive at the site via the Park Road which extends like a spine down the center of this linear island, and their destination is the beach a half mile to the east. They begin in cars and end in bare feet. The resolution of this pilgrimage across wetlands, grasses and dunes is the central planning issue of all projects on the island. In order to acknowledge and facilitate this movement, the buildings are linked and clustered along a path which progresses toward the beach in a manner responsive to topography, winds and solar orientation. Parking and outdoor activities are concentrated below the buildings to minimize the site footprint and to stabilize surfaces which shade would render less likely to support indigenous vegetation. The first elevated level has shaded, outdoor, wind-sheltered pedestrian boardwalks linking buildings and the dune crossing.
Edges to Nature
Arguably, the most critical architectural details on a barrier island site lie along the continuous line across which the site is not altered, affected or even maintained. It is a line which is often not even acknowledged to exist; but it is always explicit, unmistakable, and dynamic. There are several "rules" which this project has imposed regarding this line. First, shrink this perimeter to the minimum area required for structures and outdoor activities. Second, cross the line only with elevated boardwalks, narrow and high enough to allow vegetation and habitat below. Third, stabilize and define the edge with a low masonry retaining wall providing a freeboard to allow sand erosion and accretion and to create a pedestrian barrier to the wetlands and grasslands.
More buildings in this climate have likely succumbed to corrosion than to hurricanes, and those to hurricanes may well have already had their fate sealed by corrosion. Structural steel, even galvanized can be short lived if not exceedingly well protected; and with reinforced concrete, minor shrinkage or thermal cracks can begin an expensive cycle of maintenance and progressive structural decline. The only reinforced concrete deemed viable in this project is for concrete columns and cantilever beams designed to elevate the building envelope above tidal surges. Concrete with epoxy coated reinforcing is to be cast against sheet waterproofing at the inside of brick forms. In this manner, steel is protected by brick, waterproofing, 2" of concrete cover, and epoxy coating. The upper structure is wood frame with stainless steel fasteners, clad in fiber cement roof and wall tiles.
Ironically, because storm surges on the barrier island flow through to inland bays, they can achieve less vertical rise than further inland where the water accumulates against a land mass. The operative concept here is "flow through". By elevating the structures on massive concrete columns and a double cantilever beam grid above the grasslands well behind the dune line, the danger of tidal impact can be minimized.
The older structures on the island which have weathered the most storms with the least damage are wood frame. They tend to be low-rise and short-span which avoids accumulating large loads. They can accommodate many interior shear walls and floor diaphragms to transfer loads. They are inherently flexible which can dissipate stresses. With stainless steel connectors, they are not prone to corrosion. In this project, all interior partitions and exterior walls will have plywood sheathing and stainless steel tie-downs. Exterior walls and roof will have a ventilated cavity for solar shading, moisture drainage, and to provide and intermediate pressure cavity for wind resistance.
Water Resources & Wetlands Management
In its natural state, the barrier island has no runoff. Water percolates very quickly and replenishes a high fresh water table which can extend even below the salt water beach. By having virtually no impervious surfaces, this project neither impacts ground water conditions nor requires storm drainage infrastructure. It is an effective rainwater collection system that requires only to be left alone. The lower elevation parts of the site contain a wetlands bog and freshwater pond which support bird and small mammal habitat.
Environmental Activities and Education
The Mustang Island Episcopal Adult Conference Center and Youth Ecology Camp is designed to facilitate group and individual recreational, educational, and spiritual activities. Surrounded by natural wonders, the Adult Conference Center is conceived to a quiet place for spiritual renewal and celebration. A variety of meeting spaces, both indoor and outdoor, are provided to facilitate small and large group meetings. The Youth Ecology Camp is conceived to provide the youths with experiential opportunities for spiritual and fellowship development as well as providing a living laboratory for the development of environmental consciousness and responsibility. There will be hands-on opportunities for the study indigenous plants and animals, aquatic life and the ecological system of the barrier island. This camp can offer round-the-clock experience on the barrier island, heightening the youths' appreciation of the drama of nature as it moves from day into night and night into day.
Environmental activities include:
passive solar systems
natural lighting and ventilation
water resource management
low-impact, renewable resource materials
dune re-vegetation and regeneration
resource management and recycling
The vast majority of Texas Gulf Coast barrier islands are state and federal lands protected from development. Several miles of privately owned land, however, is platted for development with utilities and transportation infrastructure in place and market demands increasing. Projects to date have not met the technical, environmental, or human challenges posed by this collision of economic demand and environmental sensitivity. If the nature of future development is not altered, then architecture will have missed a unique opportunity to demonstrate an environmental consciousness and viability in a setting where purpose and skill are laid bare by a powerful and unforgiving context. Conversely, if we can develop architectural models that demonstrate the ability to respectfully and happily coexist, then such models can provide the venue through which people's inevitable trips to the beach can be informed by a consciousness that will ultimately serve to protect these barrier islands from development.