Elements of
Site Analysis

Here Comes the Sun

by Jeffrey K. Smith, AIA, NCARB

“Architecture is a science arising out of many other sciences, and adorned with much and varied learning; by the help of which a judgment is formed of those works which are the result of other arts.”

- Vitruvius, Roman author, architect, civil and military engineer during the 1st century BC

As architects, we go through rigorous training on how to analyze a building site. As I pen this document, it is like stating the obvious; however, we must realize that our education and experience are unknown to many who have needs in the built environment. This missive will attempt to decipher the process we follow each time we begin designing a project, regardless of size and scope. Even Vitruvius, in his ten books on architecture, defined in great detail how to choose the best site for a new town in the natural environment. The same principles can be implemented in our current considerations in selecting a building site and how to locate a structure on the site.

As we advance our building technologies, we can combine them with the passive concepts that the prodigy builders in the past used out of necessity and meet the challenges we face to reduce energy reliance. As architects, our ultimate goal should be to design buildings that produce energy rather than consume energy. This is an audacious goal, but it is achievable.

The following are site analysis considerations that we utilize every time we assist with site selection or begin a building design for our clients. These factors inform our design solutions that we define as regional modernism.

“The sun never knew how great it was until it hit the side of a building.”

― Louis I. Kahn, American architect

Solar

With a compass in hand, we visit the site and study the topographic survey to determine how the sun will track across the site. In my opinion, this is the essential factor architects must analyze as we consider site selection and building design. Knowing how the sun will impact the building through the day and various seasons and what part of the world your site is in will determine the building's floor plan and fenestration. The ultimate goals of sun analysis are to harvest natural light into all functional spaces, limit solar gain, and potentially utilize solar energy. Site constraints will impact the solar strategies, such as street orientations, surrounding buildings, vegetation, and/or topography. The siting of a building properly on the property and development of the features that address the site constraints should inform the design. Computer technologies are also utilized to create energy models of proposed designs to increase energy efficiencies.

Solar analysis for The Pond House at Ten Oaks Farm

“Let us green the earth, restore the earth, heal the earth.”

― Ian McHarg, Scottish landscape architect and writer

Topography

A topographic survey is an absolute necessity before beginning a site analysis in South Louisiana. Our sites are mostly flat, which can be even more problematic than a sloping site. Knowing if the site is in a flood plain or floodway and the Advisory Base Flood Elevation (ABFE) must be determined. Location of the building and site features, such as drives and parking, will be impacted by the topography. The development of drainage strategies for the building and site must be thoughtfully considered to comply with jurisdictional ordinances and environmental management of the water on site. Topography could also affect adjacent structures, infrastructure, vegetation, and view corridors. The existence of wetlands is also a major design consideration and must be addressed. Sustainability considerations for water management on site should be included in a typography analysis, including such features as the potential for bioswales and retention ponds.

The Fold House

Tree at my window, window tree,
My sash is lowered when night comes on;
But let there never be curtain drawn
Between you and me.

― by Robert Frost (Excerpt from Tree at my Window)

Vegetation

Sensitivity to significant vegetation is also an important factor to consider during site analysis. In many jurisdictions, there are ordinances against removing trees, specifically Live Oak trees in Louisiana. These ordinances support our design philosophy, which we learned from Ian McHarg’s book, Designs with Nature. Knowledge of where significant trees are located and the species of the tree will establish site design considerations. Can the trees being saved tolerate construction activities, and should an arborist be consulted? Understanding the existing vegetation will also inform the landscape design of the proposed project. The site vegetation location will impact the project design in innumerable ways, including, most importantly, the sighting of the building, fenestration, and material selections.

Russell B. Long Federal Building and Courthouse

"Streets moderate the form and structure and comfort of urban communities."

― Alan B. Jacobs
Urban Designer and author of “Great Streets”

Circulation and View Corridors

How you access any given site will have a significant impact on the site selection and design. What is the access for cars, trucks, mass transit, and how will pedestrians arrive at the site? Urban site street grids make this site factor rather obvious; however, thoughtful consideration must be given to zoning ordinances, state highway requirements, and sidewalk designs that will interface with vehicular requirements. Large-scale projects, on-site parking, and landscaping become critical to the ultimate success of the design. Reviewing applicable codes and ordinances is the first step, then sensitivity to how the structure will face the community becomes a key design moment. This is when the view corridors come into play. How the structure is viewed from the surrounding streets and how the occupants will see into the surrounding community must be recognized. Integrating landscaping into the site design should involve consulting with a landscape architect to respect local vegetation and support the designs of all structures on site. Landscaping can be used to screen unsightly necessities and enhance view corridors. A missed opportunity on most site designs is the pedestrian experience. Parking lots tend to ignore how people get from their cars to the building.

Iberville State Office Building

“I hope you will understand that architecture has nothing to do with the inventions of forms. It is not a playground for children, young or old. Architecture is the real battleground of the spirit.”

― Ludwig Mies van der Rohe, American-German architect

Context

During the site selection/site analysis phase, the surrounding context will become another key component. Evaluating the vernacular of the neighboring buildings should become a guiding design factor for a project. A detailed analysis of the surrounding architecture, including compliance with any overlay district requirements such as historic districts or development design covenants, should be rigorously documented. A photo essay of the significant architecture in the area is a great resource. It is important to note that mimicking the neighboring architecture should be avoided, instead, thoughtfully respecting the architecture with a regional modernist approach should be considered. Even a modernist intervention can add interest to a streetscape and be a delightful addition in a historical setting. This is also the National Park Service Historic Preservation recommendation in their guidelines for historic districts. Renovations, restoration, and adaptive reuse projects are highly recommended in historic areas, maintaining the historic street fabric while modernizing a building for reuse. The most sustainable building is one that already exists.

Baltzell Building

"Consider if you are required to design a flight of stairs or a sidewalk, there are clear and straight regulations, and we should be thankful indeed for these codes of protection. But there is no comparable concern reflected in most laws, that ensures that your house is not built on a flood plain, on unconsolidated sediments, or in an earthquake zone, hurricane path, fire-prone forest, or in an area liable to subsidence or mudslides."

― Ian McHarg, Scottish landscape architect and writer

Conclusion

In the late 1960s, Ian McHarg made his impassioned plea in his book Design with Nature to bring awareness to site evaluations, not unlike Vitruvius 2,000 years earlier. Our governing entities are finally starting to regulate our building site to some degree, but we can do more. Hopefully, this will help you next time you consider a site for your home or business. As architects, our ultimate goal is to achieve the delicate balance between the natural and built environments by creating architecture that meets human needs for habitation while respecting the natural world. With rigor and thoughtful consideration of the concepts presented, we believe that as a society, we can reach this goal.

H/S EXPERIENCE

As human beings, we spend our personal and professional time within the built environment. As Architects, we are privileged to create spaces where people can gather, live, learn, work, eat, sleep, and worship. Therefore, it is incumbent that we design spaces that enhance the quality of life and nurture a greater passion for living. Our design approach is influenced by the environment, culture, and community in which architecture exists. To take it further... We Design for Life.

Jeffrey Smith has used his architectural knowledge to assist the communities of Tangipahoa Parish in developing master plans based on Smart Growth principles. He has served in the Hammond Historic District Commission, the Hammond Downtown Development District, the Chamber of Commerce board, and the Hammond Planning and Zoning Commission. His architectural career has balanced his dichotomy of a love of both the natural and built environment. He is also past president of the New Orleans and Louisiana chapters of the American Institute of Architects (AIA).