## Green Roof Wittenberg (Assignment Due Monday, April 22nd)

As we work toward a green roof at Wittenberg, what calculations are needed to determine costs and return on investment? Would this attract you as a visiting student? And wouldn't this be a cool place to have a research project, or a Global Climate Change Lab?

## Part 1: Choose one of the roof segments to make green

(3 pt) 1) Which segment of the roof would be the best candidate for a roof (a) the northwest square, flat, black roof, (b) the central, flat, rectangular, black roof, (c) the northeast rectangular, sloped roof, or (d) the southwest white roof? When describing your choice you should consider which roof section would be easiest to install, most visible for aesthetic appeal, improve the heat island effect by increasing albedo, and cover the greatest area for most stormwater reduction. Full credit will be given if you consider at least 3 factors in your decision. You may refer to the Environmental Impact slides compiled by the class (posted on Moodle).

(2 pt) 2) a) Using the scale bar, calculate the area of the roof segment that you would like to make green. Show your work. (Your answer will be in meters squared).

(2 pt) 2) a) Using the scale bar, calculate the area of the roof segment that you would like to make green. Show your work. (Your answer will be in meters squared).

## Part 2: Estimating benefits

(numbers from Ann Arbor Michigan Study; Clark et al., 2008, Environmental Science & Technology)

In this activity you will make calculations based on a study done in Ann Arbor, Michigan. First you should consider if this is a valid location to compare to Springfield

(1 pt) 3) From the below precipitation map, will the reductions in stormwater runoff be similar at Wittenberg in Springfield, Ohio to Ann Arbor Michigan? (Be specific).

(1 pt) 3) From the below precipitation map, will the reductions in stormwater runoff be similar at Wittenberg in Springfield, Ohio to Ann Arbor Michigan? (Be specific).

(2 pt) 4) a) What is an ecoregion and which one is Springfield, Ohio in? (You may need to look this up, if so cite your source).

(1 pt) b) From the below map, is Springfield in the same ecoregion as Ann Arbor?

(1 pt) c) What might that mean for the types of plants that would grow well on green roofs in both places (would they be similar or different?)

(1 pt) b) From the below map, is Springfield in the same ecoregion as Ann Arbor?

(1 pt) c) What might that mean for the types of plants that would grow well on green roofs in both places (would they be similar or different?)

(2 pt) 5) A conventional roof installation costs $167 per square meter and a green roof costs 39% more. What is the cost of the green roof that you would like to build (from part 1). Show work.

(4 pt) 6) A conventional roof will need to be replaced after 20 years. A green roof will last 40. Calculate the total cost associated with roofing for a conventional and a green roof. To make this calculation, you should also subtract from the green roof any energy savings incurred, & savings in stormwater fees (e.g. 15% of $8000 annually, we will assume no cost increases through time which is a very low estimate). The roof will save ~$500 in gas an electric annually (we will assume no increased cost through time, which is a very low estimate). (Note that these numbers are derived from this calculator based on selecting a black, old office roof & assuming a leaf area of 3 which shows some dark soil). Let's assume that plants selected require minimal irrigation and that any irrigation costs would be covered by costs associated with rising heating/cooling/stormwater costs.

(1 pt) 7) From the above, would you recommend a green roof for Wittenberg for financial reasons. Describe.

(5pt) 8) Create a bar graph that shows the total cost of a green roof vs. a conventional roof for the HPER building after 40 years. Label the x and y axes with units and give an appropriate title.

9) (2 pt) a) The Ann Arbor study also suggests that the air quality improvements associated with green roofs (reductions in harmful pollutants that impact the young and the elderly) have a minimum value of $0.45 per meter square of roof per year in health cost savings. The maximum value in health savings is as much as $1.70 per meter squared per year. From Part 1, how much money in community health costs would be saved each year if we install your green roof? Give the low and high range, show your work.

(1 pt) b) Why do you think that health costs associated with burning fossil fuels (dirty emissions that harm health, warming & associated environmental damage, such as lost crops due to drought, or salinized fields due to sea-level rise and intrusion into aquifers used to irrigate) are not included in the price of fossil fuel?

(4 pt) 6) A conventional roof will need to be replaced after 20 years. A green roof will last 40. Calculate the total cost associated with roofing for a conventional and a green roof. To make this calculation, you should also subtract from the green roof any energy savings incurred, & savings in stormwater fees (e.g. 15% of $8000 annually, we will assume no cost increases through time which is a very low estimate). The roof will save ~$500 in gas an electric annually (we will assume no increased cost through time, which is a very low estimate). (Note that these numbers are derived from this calculator based on selecting a black, old office roof & assuming a leaf area of 3 which shows some dark soil). Let's assume that plants selected require minimal irrigation and that any irrigation costs would be covered by costs associated with rising heating/cooling/stormwater costs.

(1 pt) 7) From the above, would you recommend a green roof for Wittenberg for financial reasons. Describe.

(5pt) 8) Create a bar graph that shows the total cost of a green roof vs. a conventional roof for the HPER building after 40 years. Label the x and y axes with units and give an appropriate title.

9) (2 pt) a) The Ann Arbor study also suggests that the air quality improvements associated with green roofs (reductions in harmful pollutants that impact the young and the elderly) have a minimum value of $0.45 per meter square of roof per year in health cost savings. The maximum value in health savings is as much as $1.70 per meter squared per year. From Part 1, how much money in community health costs would be saved each year if we install your green roof? Give the low and high range, show your work.

(1 pt) b) Why do you think that health costs associated with burning fossil fuels (dirty emissions that harm health, warming & associated environmental damage, such as lost crops due to drought, or salinized fields due to sea-level rise and intrusion into aquifers used to irrigate) are not included in the price of fossil fuel?