Our architecture firm Future Math Teachers of America (FMTA) has been hired to design and build an office building for Izsák Industries (I^2). Our client has already purchased their site, and needs our professional expertise to evaluate the development possibilities. Before we can hit the drawing board, let's review some of our industry terminology.
ZONING ORDINANCES
Every city, county, and state imposes their own specific constraints on buildings constructed within their boundaries. Zoning ordinances are laws originated and adopted by a municipality to control land use, density, lot coverage, and even building height in an effort to protect public health and safety. They also help to minimize conflicts between property owners, such as noise, traffic, and hazardous materials. In order to understand the mathematical constraints that zoning ordinance impose on site development, we first must define the following terms:
Right of way- The right of way is a measurement that includes the width of the road as well as additional equal area on either side of the road. The extra area provides space for public access, sidewalks, and water drainage. It also allows for future street expansion, utility lines, fire hydrants, etc. It is the property owner's responsibility to maintain the right of way adjacent to their site; however the property owner is not allowed to develop on this area.
Setbacks- Setbacks are specified distances from site property lines that are useful in preventing the spread of fire, reduce noise transmission, and preserve green space. Even though setbacks lie inside of the property lines, property owners are restricted from developing within the area designated by the setbacks.
Green Space- Green space refers to any area of a site that is left to vegetation or water, rather than built upon. Essentially, any space on the site that is "green" is considered green space. Note that setbacks are also considered green spaces.
THE TOTAL SITE
Izsák Industries has high expectations for their site, so our calculations must be accurate and our drawings must be professional! Whenever necessary, round all numbers to two decimal places. All dimensions on the site drawing should be expressed in feet and inches like: 10'-0".
1. Use a ruler and the given scale of 1/4" = 20'-0" to determine the size of our client's site, in feet, attached on page 8. This means that every 1/4" on your ruler actually represents 20 feet and 0 inches on the drawing. Label the length and width on the site drawing. What is the area of this site?
2. The local zoning ordinance dictates that a 60 foot wide right of way be used for all public roads. Our site lies adjacent to a road that is 40 feet wide on the south side, but the right of way lies completely outside of our property lines. Use a ruler to draw in the right of way, and the public road. Be sure to label the dimensions of the width of the road, and the space on either side of the road. Also, give the road a fancy name!
3. Upon further review of local requirements, we find that we need to account for set backs on our site. Draw dashed lines on our site to represent the following setbacks: 25'-0" on the north side, 35'-0" on the south side, 10'-0" on the west side, and 10'-0" on the east side.
a. What is the area of our site that is now designated by all four setbacks? (i.e. What is the area between the property lines and the setbacks?)
b. What percent of the entire site is this?
4. Before we can begin to discuss building sizes, we must address the green space requirement. According to the zoning ordinance, we need to designate 35% of our total site area for green space. Remember, green space can include the area calculated as setbacks, but may also need additional site area to meet the requirements.
a. Since we have found the percentage of setback area in 3b above, what is the percentage of our site that we need to add to that, to meet the 35% green space requirement?
b. How many square feet is this added area?
c. Draw a rectangle (to scale) on the site that represents this additional area we are not allowed to build on. Mark your dimensions on the drawing, and label this area "green space." To mark your dimensions, you should estimate to the nearest 3 inches (or .25, 1/4, of a foot). Also, think about where the best place is for the green space. Where would you put the green space in order to leave the most buildable area together?
d. So, what is the total area of land that cannot be used for development? (i.e. the area that is either reserved as green space and/or setbacks.)
5. Finally, we are able to compute a maximum buildable area for our site. We need to find the difference between the total area from question 1 and the unusable area from question 4d.
a. How much area can we use to build on? This figure will represent the maximum buildable area, or M, for our site.
M =
b. I2 has purchased a large site to build on, but by law is we are not allowed to build on every square foot. So, based on your answer in 5a, what is the percentage of the site that we are actually allowed to build on?
THE BUILDABLE
AREA
Now that we are able to tell our clients how much land they have left to build on, they decide immediately that they want to place a 20,000sqft building on the site. The first questions they ask are "Will this fit on the site with the required parking?" and "How much space will we have left over?"
1. So, right away we dive into the local code books and find some constraints that will dictate how much area is necessary for the building and parking. Since our client wants to build an office building, we find that we will need to account for 1 parking space for every 250sqft of building.
a. How many parking spaces are required for the size of building the client has requested?
b. Standard codes specify that each parking space must be 9'-0" wide and 19'-0" long. What is the area of ONE parking space?
c. What is the total area of ALL the parking spaces required for our building?
2. Parking area does not only include the parking spaces. It also must include space for cars to move between parking aisles, and for car entrances and exits. We will assume that we need to increase the parking space area by 60% to account for these extra spaces.
a. Now, with the 60% increase, what is the parking area for our 20,000sqft building?
b. Let x represent the size of a building. Write an expression in terms of x for the entire parking area. Simplify your expression as much as possible.
parking area =
c. Now we are able to tell I2 how much area will be used on the site for the building and parking. We describe the total built space, or T, as the building footprint plus the entire parking area. What is the total built space for our 20,000sqft building?
d. Write a general expression in terms of x (the building size) for the total built space.
T =
e. Now, we are able to tell the client how much area will be left over. We know how much area we are allowed to build on, and now we know how much area a 20,000sqft building and parking will occupy. So the leftover space, or L, is described as the area we are not using. What is the leftover space of this site?
f. Write a general expression for the leftover space (L), in terms of total built space (T), and maximum buildable area (M)
L =
g. Pleased with the outcome of our calculations, the clients have decided they definitely want the 20,000sqft building on the site. Draw a reasonable looking rectangle on the site that represents this area (keep in mind what shape rectangle a building may be). Be sure to label the dimensions of this area and give the building a fancy name. Adjacent to the building, draw a rectangle to represent the parking area. This can be cleverly labeled "parking." Be sure to maximize your left over space. (i.e. leave enough room for future building area by drawing your building and parking adjacent a setback line or the green space).
3. After seeing how much leftover space our site has, the client has decided they would like to add a building that has a footprint of 33,000sqft. Of course now, we have to consider all of the parking requirements for this new building.
a. Using the same parking constraints as before, how many parking spaces will a building of this size require?
b. We can use the general expression in question 2b to find the size of the entire parking. How many square feet are required for parking for this 33,000sqft building?
c. Refer to the general expression from question 2d. What is the total built space required for this added building?
d. Now, we can use the general expression in 2f to find the leftover space. After adding the second building to our site, what is the left over space now? Be careful to use the correct value for M. Since there is already the 20,000sqft building on this site, our maximum buildable area has been reduced!
4. I2 has decided that they want to maximize the use of the site. They were unsatisfied with all of the leftover space we had after adding the 33,000sqft building, so they would like us to tell them what size the second building should be, to result in NO leftover space at all.
a. What is the largest possible building area that will result in no leftover space? Have we already developed a general expression to simplify these calculations?
b. How much parking area will be necessary for a building of this size?
c. How much left over space will you actually have with this size building and parking area? Will the client be happy?
5. As architects at FMTA it is our job to ensure all of the code requirements are met before we begin our design. As you have seen, coordination with the client is important to assure they are getting the building and site that they want. Therefore, presenting I2 with different design options is helpful.
a. If the clients were looking to put a building on the site that would not fit with parking, what are some practical options you would recommend for solving this problem?
b. If they wanted to maximize the building area on a site, and minimize the parking area around the building, what other options would they have for parking placement? What considerations are necessary?
SITE DRAWING
Click here
to use the Geometer's Sketchpad site drawing.
Return to Essay 3 - Site Planning Activities