Table 2 The indicators of the three sustainability aspects are related to SGWs [9, 10, 12]

1

The social, physical, and cultural levels.

Estimating the construction budget and the initial cost and all costs must be calculated for each building separately.

In this appropriate plant type for the climatic nature, if the coastal environment, the soil saline, and acidity increase.

2

Some facades deteriorate and need restoration.

Many variables affect the capital required, such as the plant type, facade conditions, transporting materials, and availability of materials.

It is essential to avoid plants that produce a large amount of water vapor through the transpiration process, thus increasing the relative humidity.

3

Agricultural awareness and culture.

To reduce cooling loads and energy costs.

The suitable plant type is selected according to wind features not to harm the structural loads.

4

The population is ready to do the necessary maintenance periodically.

It requires more capital, but this difference returns to the owner through the economic life cycle, so the budget shows recovering the cost difference by saving.

The density of the plants’ leaves and their nature (deciduous-evergreen) according to the direction, the permeation of moist air during hot periods, and the prevention of dust-laden winds and direct sunlight from entering.

5

Social cohesion among residents.

The cost of staff qualified in all phases technically.

The plant type is according to the available water, irrigation methods, and drainage.

6

To enhance the psychological state and reduce the stress of living.

Many variables affect the maintenance costs, such as the facade condition after use, the cost of transporting materials, and the availability of materials.

Balancing the use efficiency of plants and environment preservation is by choosing the appropriate plant type for the surrounding environment, climate, and prerequisites for water use and drainage, especially in dry areas.

7

Aesthetic values

To increase the value of a building.

Recycling rainwater and greywater are for irrigation.