Design and Development of a Roof Garden
- Design Parameters -
(page 8/10)

Also, as previously mentioned, automatic fill and management of the water levels is an important consideration in the feature design. Evaporation will easily reduce the water level by 3-4” per day in hot windy conditions. An auto-fill feature will protect the expensive pumping and filtering systems.

Planting of water plants will greatly improve the quality of the water and prevent algae from becoming a problem. Additionally, the use of a biomass filtering system will provide the necessary filtering without the use of chemical agents.

KEY POINTS: Selection of Hardscape Elements
The omnipresent factor of weight has a strong effect on which materials are used and their placement in the landscape.

• Consideration of the reflectance of the paving materials should be of primary consideration.
• Provide adequate seating, the comfort of the user impacts the overall usage of the project.
  
• Furniture should be heavy enough to not require anchorage.
  
• Wood furniture is preferred.
  
• Make appropriate provisions to replenish water in features to combat the effects of evaporation.
  
• Use a flexible water retainage system to mitigate the effects of the Minnesota climate on the pool system.

Provisions for Utilities
Electrical
Standard 110-120 Volt ac electrical supply is sufficient for most roof garden uses, such as lighting, appliances, fountains and irrigation controllers. All electrical requirements should be met in accordance with the electrical engineer’s recommendations.

Water
A supply of clean water is needed for irrigation, pools and fountains and the cleaning of paved surfaces and furniture. Water pressure of the irrigation system should be provided from a minimum of 35 psi to a maximum of 70 psi.

Storage
Provisions should be made for the storage of gardening materials and supplies. This storage should be water tight and readily available to the horticultural staff caring for the garden. Additionally this area can function as the location of controllers and electrical panels for the garden.