1. Ignorant

From September to October 2014, we had sent 975 mails to different building owners and managers, asking for a venue to conduct roof greening. Although we stressed in emails that “the project would not incur any cost, maintenance affairs and structural issues”, less than 2% receivers response to our emails. Most of them simply reject our proposal with no reasons. This shows the ignorance among the public.

 

 

2. Cost (material cost, sponsorship)

a. Initial cost of installation (Increase of design and construction cost)

The major capital cost of a green roof is the initial installation. For extensive green roofs, the range of cost is around $400 to $600 per square meter depending on the quality of systems. For intensive system, the cost is ranging from $1500 to $5000 per square meter.

For our project, which is to install 10 square meter of green roof has a total budget of HKD 5000, and it is hard to find companies to sponsor us and thus the burden fell to the users' shoulder. As a result, many users, 95% of those who said interested when it didn't cost, turned away from us due to the inability to pay for it.

 

b. high maintenance cost

Regular maintenance, e.g. watering, fertilizing, weeding and even gardening is needed for the roof greening, which incurs high cost to owners if they want to keep the green roof alive and functional. The maintenance cost decreases with the complexity of the roof design.

 

3. Man-power & time consuming

 On the day of installing our green roof, we utilized 6 people and 2.5 hours. The process was tiring as it involved moving sacks of soil and trays. And the sowing process of pouring the soil into the trays took as the longest time and stamina. Therefore, high demand of man-power is shown in roof greening when installing. Even after the installation, we have visited the roof once every two days for checking its growth.

 

4. Liability & management issue

The types of organizations we sent e-mails to included only schools, NGOs and property management companies. The large sector of residential buildings which are not managed by a property management company cannot be reached as we don't know who to approach. There is often a multi-ownership problem of the roof in the residential buildings which would make them difficult to implement and manage roof greening. Another problem concerning the choice of residential building is that it would be difficult for us to enter the premises as an outsider and to green the roof. Management company may find it difficult to let us visit the roofs located in a private housing frequently, the security problem needed to be addressed. There are also concerns who to enter the roof. As most of the roofs do not have safety barriers, there is no one to warrant the safety of the worker when installing greening systems.