Investigation and research into the Persian Gardens, leading this project into a step that these World Heritage Sites might have been known as sustainable construction, but the fact that water scarcity of their region is a serious threaten for all these amazing Gardens. Thus, enhancing and improving these gardens by merging, adding and adapting todays technologies can make them considered as constructions with water and energy conservation design. Based on nowadays world environment concerns, recognizing renewable and non-renewable sources of energies in a region or site can cause a miracle. Since, almost all Persian Gardens located in regions with arid and semi-arid climate, water poverty as a biggest issue and nonrenewable energy should be included as a problematic concern. There are many available active and passive strategies that can be applied in these heritage sites which decrease water consumption either directly or indirectly. Such as water harvesting, greywater reuse, photovoltaic panels and material changes. Water known as a vital element of each garden for irrigation purposes, but in Persian Garden water is more than a functional element. Thus, finding a way to provide and recycle water beside the underground sources is necessary. Subterranean, springs and wells are resources of water for Persian gardens which renew so slowly or non-renew these days. Being so close to a city with considerable population lunches and idea of using greywater for irrigation in these gardens. In this research, the doable options for energy conservation design for these sites will be discussed, then comparing some case studies in all over world where greywater reusing water system for irrigation is happening will be next step. In conclusion, greywater reusing system in urban scale in order to irrigate a filed or garden will be investigate on a Shazdeh Garden as a main case study of this research.