Monetary Outputs and Inputs


Table 1: Cost Capital and Recurring Costs

Projecting the cost and revenue of the programme was crucial for the development of our proposal to both corporate funders and to city agencies. Our sponsors provided us with a cost breakdown for the rooftop garden at 44 Wale Street to supplement our research, which helped us to identify the necessary cost factors.

Once we refined the start-up cost, we determined the annual recurring cost, including salaries for two years and costs for training, maintenance, water, and seeds. In our proposal, we asked for funding to cover the recurring costs for the first two years, after which it is anticipated that the programme will generate enough revenue to pay the workers and cover its recurring costs.
Determining the start-up and recurring costs allowed the team to estimate the funding needed for the entire rooftop programme and a pilot rooftop garden on the Prestwich Memorial building. Initially, these costs were high and represented an ideal rooftop garden setup. Our sponsor saw the expense of the ideal rooftop and requested pricing for a less expensive pilot garden. We were able to significantly cut down our costs to make the rooftop programme and pilot garden feasible by finding cheaper ways to produce oyster mushrooms and taking out items like lattices that did not affect production.


At the beginning of the project, our sponsor stipulated that the rooftop gardens would grow oyster mushrooms, alfalfa sprouts, mung bean sprouts, and brussel sprout micro greens. In order to calculate revenues, we researched the likely production levels and local wholesale prices. We had trouble finding these figures for the micro greens, so our sponsor suggested we extrapolate based on data of mung bean sprouts we could find at the grocery store. Based on this method, the estimated revenue numbers were extraordinarily high; according to our advisors, our revenues were overestimated by a factor of ten. We found a website which specialized in micro green production and gave production levels for micro greens based on weight and planting practices. Using these guidelines, we were able to generate more accurate revenue numbers. Since our calculations did not take into account several uncertainties, such as Cape Town’s strong winds and hot summers, plant disease, variable germination rates, and the learning curve for the gardeners, we reduced our projected production volumes to 30% of the calculated value.

Table 2: Revenue for 1000 m2 programme


Table 3: Supervisor and Gardener Incomes

As part of the programme, we anticipate that for the first two years, the gardeners and supervisor will be paid a salary provided by the funding and the service provider will be paid based on profit. We plan for the gardeners to make the Cape Town minimum wage of R8.95 per hour and for the supervisor to make the average Cape Town salary for a manager in sales, which is R13 000 per month (Minimum, 2012; Salary, 2012). Salaries for two years at these rates have been incorporated into the funding request. 90% of any generated revenue during the first two years will go into the programme reserve and the remaining 10% will go to TEL.

After the first two years, the rooftop gardens should be sustainable and the income of the gardeners and supervisor will be profit based, both of which need to be incorporated into the profit breakdown. To establish the profit breakdown, we first calculated 30% of our revenue that was projected assuming a perfect harvest which accounts for complications such as gardening mistakes, spoilage, plant disease, and weather damage. The adjusted revenue this generates is R1 085 754 ($125 317). We subtracted the projected maintenance cost of R450 000, leaving a profit of R635 754 ($73 378) . We determined that to match the incomes the workers received during the first two years, 45% of the adjusted profit will be divided amongst the gardeners and 25% will go to the supervisor. TEL will get 10% of the profit leaving 20% for the reserve. Table 3 shows the comparison of the incomes of the gardeners and supervisor for the first two years and for the years to follow. The incomes are nearly identical which will provide a smooth transition when incomes switch from salary to profit based.

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