Week 3: Chapter 2- Site Considerations and the Building Enclosure

 Chapter 2

Site Considerations and the Building Enclosure 

In Chapter 2 we learned about the building systems that are used within a building. These are divided into groups, they are, Structural systems, mechanical plumbing and electrical (MPE) systems, enclosure systems, and interior systems.

The Site

the architect is responsible for placing the building on the site. This job might also include the engineer and the landscape architect. Reasoning for the placement of the building might include, the relationship with the sun, wind, the surroundings, and the slope of the land. The placement of the building has a large effect on the amount of energy that is used for the building.

Overall site considerations

Regulatory 

• address the various 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 setbacks from property lines, as well as the 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. How 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-include species to be protected or reintroduced to the site; prevailing winds; sun patterns; and the existence and location of water bodies.
• Man-made-include species to be protected or reintroduced to the site; prevailing winds; sun patterns; and the existence and location of water bodies.

How the Site Impacts the Interior

The sun

• The sun rises in the east and sets in the west. During the winter months, the sun dips towards the southern exposure in the northern hemisphere.
• Because of this, the interior spaces will experience more direct sunlight on the south side of the building. The north side of the building will have no direct sunlight which means it tends to be cooler. 
• In the southern hemisphere is the opposite. buildings that use the sun use less energy 

Wind, Cold, and Rain 

• the entry into a space needs to be handled carefully. In particularly cold and windy areas, the use of an airlock is desirable. The airlock allows people to enter into a conditioned vestibule before entering into the main lobby of the space. this keeps most of the cold and wind out of the main area.

Views 

• Important views may be showcased using interior design elements. If the interior designer is on board early enough in the project design process, he or she can also have input into the placement of windows because they impact interior needs such as daylight penetration, furniture placement, and glare minimization.

Outdoor Rooms 

•  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 main purpose of the foundation is to carry the weight of the building to the ground. Ideally, this would be distributed over a large area evenly. if the load is not distributed you get differential settlement. The second purpose of a foundation is to resist lateral forces (coming from the side). These might be from either hydrostatic pressure from water in the soil, or from earthquakes. Here are some different types of foundations. 
  
  

Walls

• walls are of one of three basic types: masonry bearing, stud wall or column, and beam structural frame with infill. All three are commonly used in construction.

Bearing Wall Construction 

• Bearing wall construction was traditionally a historic building method including either stone or brick bearing walls. Several configurations or bonding patterns were used and often reflect a specific time frame in historic construction. 

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 on center. Conventional light frame construction uses either 2 x 4 studs or 2 x 6 studs. These are nominal sizes. While historically a 2 x 4 was actually 2 inches by 4 inches, this is no longer the case, here's a graph to help understand. 

Column and Beam structural frame 

• Column and beam construction can be heavy timber, steel, or pre-cast concrete. 
• Heavy timber beams should exceed 6 inches in dimensional width 10 inches in depth for flooring and 8 inches for columns. Many heavy timber framing companies today use glue-laminated beams and columns to achieve these dimensions. Steel frame buildings combine steel columns and beams to create large open spans.
• Oftentimes a curtain-wall system is applied to the exterior. Concrete structural frames are composed of concrete columns and beams

Exterior Materials 

Several different exterior cladding materials can be used to cover stud walls, structural frame walls, and structural insulated panel walls. 

Concrete 

• Concrete is composed of portland cement, aggregate, and water. When mixed, these components undergo a chemical reaction through which they harden over approximately 28 days
• The Romans were the first to use portland cement as a building material, in constructions such as the dome of the Pantheon in Rome. 

H-UKR--Hoffman Green Cement

• High-Performance Activation Alkaline uses slag, a by-product of steel production, to produce cement with one-fifth of the normal carbon footprint

Mark West Watershed Block

• Based in Napa, California, the Watershed Materials Company has created the MWW block using 100 percent solar energy without cement. The block is composed of geopolymers from clay and crushed basalt, eliminating the CO2 output

CalPlant

• Decomposing straw from rice fields is the primary component in CalPlant, an MDF-like material that performs similarly to wood-based MDF products.

Recycled Plastic Cladding

• Kedel, based in the UK, has created a high-density recycled polystyrene cladding available in 79” and 142” lengths to repurpose materials that would otherwise be landfilled. The company claims it uses less energy in manufacturing than cement board or virgin plastics.

Stucco 

• similar to plaster and is used for exterior applications, usually over wood. Oftentimes, siding options are painted or stained, and stucco exteriors are painted.

Exterior: Roofs

Interior designers do not deal with roof framing specifically because this is a structural issue. They do, however, have to respond to the shape of the roof as it impacts the interior space. The ceiling finish also falls under the realm of the designer.

Different roof types 

Roof framing Materials 

• the three primary materials used for roof framing are metal, concrete, and wood

Wood

• Wood roof framing is either stick-built on-site or prefabricated into trusses and shipped to the site. 
• Stick-built roof framing uses light frame construction techniques with rafters and ceiling joists, whereas trusses are factory-made and delivered to the building site.
•  In both cases, framing members are placed at regular intervals (12 inches, 16 inches, or 24 inches on center). 
• Heavy timber framing relies on similar principles, albeit with much larger pieces of wood spaced much farther apart.

Metal 

• When metal is used to frame a roof, it is generally composed of open-web steel joists that support metal decking filled with concrete. The combination of concrete and steel enables the roof to work in both tension and compression.

Concrete

• Concrete beams may be used to support the roof structure. The slabs are similar to those discussed in concrete flooring. These concrete members are either poured in place or pre-cast and then transported to the site. Concrete requires steel reinforcing to resist cracking since concrete works well in compression but not in tension.

Lamboo

• Engineered bamboo beams use mature bamboo (a major source of sequestered carbon) for engineered beams, posts, trusses, and other framing materials.

Other Framing Features

After the roof is framed, it is covered with a finish material. Oftentimes, insulation and sheathing are used between the framing and the finished roofing material.

    

Exposed rafter ends are when the rafters themselves are visible beyond the plane of the exterior wall. This method was commonly used on bungalows in the 1920s and 1930s. A more finished-looking appearance is achieved when the rafters are boxed in using a soffit (horizontal) and fascia board (vertical). In this case, the soffit must be vented to prevent moisture build-up.

Cornice Returns

• During the Greek Revival period, the boxed cornices were often returned onto the gable end of the building, thus creating a cornice return.

Cupola

• A small structure located on the roof that allows for ventilation is known as a cupola. Originally a functional component, these are often purely decorative in today’s construction.

Monitor

• A roof monitor is a raised section in the middle of the roof that allows for additional lighting in the center of the space. These were commonly used in industrial buildings in the early- to mid-twentieth century.

Parapet

• The low-sloped roofs of many historic three- or four-story downtown buildings frequently had a parapet on the front facade to mask the roof behind. A parapet is a low wall located above the roof plane. The parapet is most commonly used in conjunction with a low-sloped roof.

Roofing Materials

Several different materials 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.

Flat Roofs

• Although no roof is actually flat, the term “flat roof” is used to describe one that has a very slight slope. On this type of roof, only a rolled membrane roof or a bituminous substance roof should be used.
• These roof forms are most subject to leaking because both water and snow tend to sit on them for long periods. 

Green Roofs 

• roofs with live vegetation. These have several advantages: they absorb rainwater, attract local birds and insects back to the area where the building has been placed, and reduce the overall heat-island effect and water runoff. 

Low Sloped Roofs 

• Low-sloped roofs refer to those that have a rise of 3 feet in every 12 feet of horizontal distance (3:12) 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 such as 8:12 and higher.

Thatched Roofs

• Although they are uncommon 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 roof shelter. Thatched roofs must be replaced regularly.

Rustic Shingles

• Classic Metal Roofing, located in Ohio, has created an aluminum roofing shingle composed of 99 percent post-consumer recycled content from aluminum cans.

Water 

• Whitewater: potable (drinkable) water.
• Graywater: suitable for flushing toilets, but not for drinking.
• Blackwater: raw sewage.
• Xeriscape: involves conserving water through landscaping, especially through the use of native plants and the reduction of the amount of grass that is planted on a site. Mulching is used around the plants; this approach keeps water in place and allows the site to drain easily.

Blogging Assignment 

The Harm A Weber Academic Center uses many different sustainable systems that make it a LEED-accredited building. It is a stick-made srtuckter and the walls and floor are made of pre-cast concrete and the exterior is claded with metal siding to help make the sun shine into the solar panels at the top of the building. It has a glass chamber in the middle of it to help with ventilation. It also has exterior walls that vent into the ceiling and out the top of the building. This is the heating and cooling system for the building. The roof is covered in metal and has many different roof lines. some of them are gable, some are Gambrel and some are even flat. Being about to take classes in a LEED-accredited building has taught me a lot about sustainable buildings.