Chapter 2 Site Consideration

Chapter 2 Site Consideration

Overall Site Considerations

The mechanical systems that make up a building are mechanical, plumbing, and electrical (MPE). These systems all work together to make buildings usable by human beings. Most issues related to site design and building placement can be divided into three basic categories: regulatory, aesthetic, and environmental.

Regulatory

Regulatory concerns address several different man-made conditions imposed upon a particular site as a result of zoning, building codes, and site accessibility requirements. Zoning and building codes can dictate the maximum footprint of a building, the maximum heights and the required set back from the property lines, as well as use of the building.

Aesthetic

Each site has its own aesthetic characteristics. These include views as well as site features to be preserved and highlighted. The way in which a building is placed on the site can maximize views of pleasing site features.

Environmental

Each site has its own ecosystem that contains a variety of life forms as well as weather characteristics. Human intervention on the site might also create specific environmental issues for a specific site.

Natural 

Natural site features include species to be protected or reintroduced to the site; prevailing winds; sun patterns; and the existence and location of water bodies. Sustainability rating systems, such as LEED, recommend the preservation of prime agricultural land, native habitats and indigenous species - both plant and animal. 

Man-Made

Human interventions can include vehicular access to site; underground and overhead utilities; previous landscaping; and the need for noise barriers to protect occupants from adjacent highway noise

How the Site Impacts the Interior 

The interior of the building is impacted based on how the building is placed on the site. There are several different factors that determine the comfort within a building like solar orientation, site appurtenances like shade trees, wind-blocking landscape, views, and other site features.

The Sun

Daylight is defined as usable sunlight and can be harvested to reduce reliance on electrical lighting. The amount of daylight that a space receives has an impact on several factors like electrical lighting, health and welfare of the building occupants, and the glare potential in the space. 

Glare is unwanted, disruptive light coming from a given source. An example of this could be light glaring off a computer screen. Some possible solutions to this are operable window treatments, interior and exterior light shelves, and space-planning solutions that take potential glare into account. 

The amount of daylight can also affect the number of light fixtures in a building. Light fixtures near a window may be on solar sensors, or simply switched separately from those located deeper in a space. 

Wind, Cold, and Rain

In addition to space planning and lighting concerns, the building entryways need to be examined carefully. The use of an airlock may be desirable, especially in cold and windy areas. An airlock allows people to enter into a conditioned vestibule prior to entering into the main lobby of the space. This keeps the majority of the wind and cold separated from reception areas, seating areas, and building lobbies, providing increased levels of human comfort. 

Views

The interior design of a building responds to where the windows are placed and what can be seen through them. Important views may be showcased using interior design elements. The placement of windows is important because they impact interior needs like daylight penetration, furniture placement, and glare minimization. 

Outdoor Rooms

Oftentimes, a building design may include outdoor spaces that are designed as “rooms.” examples include outdoor terraces, patios, breezeways, porches, and other outdoor rooms. 

Enclosure Systems

Exterior Foundation

The primary focus of the foundation is to carry all the loads in a building safely to the ground. Ideally, this would be distributed evenly, or uniformly. When the loads are not evenly distributed to the ground, the building will have differential settlement. A second purpose of a foundation is to resist lateral forces. These might be from either hydrostatic pressure from water in the soil, or from earthquakes. 

Different types of foundations can be used depending on the building’s location and the soil condition. These can be divided into two overall types: shallow and deep. Shallow foundations include slab-on-grade, crawl spaces, and basements. 

Large buildings have significantly higher loads, and deep foundations are often used to counteract the forces associated with the greater weight of the building. Two types of deep foundation systems are piles and caissons. A pile system is mechanically driven into the soil and a caisson is reinforced, cast-in-place concrete. A caisson relies on end-bearing as well as side friction. The pile system relies exclusively on only side friction. 

Exterior Walls

There are three basic types of walls: masonry bearing, stud wall or column and beam structural frame with infill. 

Bearing Wall Construction

Bearing wall construction was traditionally a historic building method including either stone or brick bearing walls. The bulk of contemporary bearing wall construction consists of concrete block or cast-in-place concrete and is most often used in foundation walls

Stud Walls

Stud walls are made from either light-gauge steel or light-frame wood construction. Wall studs are placed at regular intervals usually 12 inches, 16 inches, or 24 inches from the center of one stud to the centerline of the next one. The studs act together as a unit. Conventional light frame construction uses either 2 x 4 studs or 2 x 6 studs. 

Column and Beam Structural Frame

Column and beam construction can be heavy timber, steel or pre-cast concrete. Many heavy timber framing companies today use glue-laminated beams and columns and beams to create large open spans. Oftentimes, a curtain wall system is applied to the exterior. 

Exterior Materials 

There are several different exterior cladding materials that can be used to cover stud walls, structural frame walls and structural insulated panel walls. Sustainable siding options include Forest Stewardship Council (FSC) certified wood shingles or boards, concrete panels and concrete board siding, and stucco.

Exterior Roofs

Interior designers don’t deal with roof framing because this is a structural issue. They do have to respond to the shape of the roof and how it impacts the interior space. The ceiling finish also falls under the realm of the designer 

Roofing Materials

There are several materials that are used to finish roofs. The primary purpose is to shed water away from the roof framing and ultimately the interior. The type of finish material that can be used is related directly to the slope of the roof. Low sloped roofs can use only certain materials like asphalt shingles. Other materials like standing-seam metal and slate can be used on a steeply pitched roof. 

Flat Roofs

On this type of roof, only a rolled membrane roof or a bituminous substance roof should be used. These roof forms are most likely to leakage because both water and snow sit and accumulate for long periods of time. Ballast can also be used to hold the membrane in place. 

Green roofs are roofs with live vegetation, and they have several advantages to them. They can absorb rainwater, attract local birds and insects, and reduce the overall heat-island effect and water runoff. The heat-island effect is the condition where the local microclimate temperature is higher because heat has been absorbed by roads, sidewalks, and buildings, which causes the local area temperature to rise. 

Low Sloped Roof

Low sloped roofs refer to those that have a rise of 3 feet in every 12 feet of horizontal distance or less. The primary materials that can be used on this type of roof include double-layered asphalt shingles, rolled asphalt, and corrugated metal roofing. 

Sloped Roofs

Most materials can be used on roofs with a pitch over 4:12. These include tiles, shingles (wood and metal), and standing-seam metal. Slate is recommended for roofs with steeper slopes like 8:12 and higher. Since slate is very heavy, it can only be applied to a roof framed for this weight. 

Thatched Roofs

Even though they aren’t common in North America, thatched roofs are used in other parts of the world. The thatch is composed of dried vegetation that is strapped together to provide a rood shelter. They must be replaced regularly. 

Living Machine

The living machine is a wastewater system that mimics a wetland environment. Its design is to treat raw sewage through a natural purification process. This takes the wastewater from the building and processes it naturally. This can be used for either site irrigation or toilet flushing. 

 

Harm Weber Building Study Analysis 

The dominant building material is concrete, both in the wall and floor/ceiling elements, which is necessary for the purposes of thermal mass. Thermal mass is a key component of the natural ventilation system. In most cases, the ceilings and walls are exposed as radiating surfaces for warmth or coolness. Primarily for acoustic purposes, there are many areas that have suspended ceiling treatments, and many others with tack-able wall surfaces.  

The exterior walls are stick framed extensions approximately four feet from the pre-cast concrete walls. These volumes contain the chase spaces for the vertical air flow in the natural ventilation scheme. It also provides a relief for solar shading. The exterior finish materials are brick veneer at the lower level, and a combination EIFS and metal panels at the top. Windowsill, jamb and head are finished in a white metal panel system, primarily to indirectly bounce day light into the facility. It also uses a Natural Ventilation system. Built primarily of pre-cast concrete, the building will draw cool air at the lower level, circulate this air throughout the facility through various routes, and ultimately exhaust the air through roof termini.