A novel green rating system for existing buildings

Green buildings are becoming an essential part of sustainable development. There have been several research trends for green buildings since 1995. The present study presents a roadmap for green/sustainable research trends and proposes a new green building rating system for existing buildings. A questionnaire was established and answered by experts, where answers were analyzed using the decision-making tool Analytical Hierarchy Process. Analytical Hierarchy Process is responsible for weighing and ranking the weights of alternatives. A novel checklist for existing buildings was structured and consisted of seven main categories, each comprised of different subcategories with different weights according to their importance and priority. The newly proposed rating system and Leadership in Energy and Environmental Design (LEED) for maintenance and renovations were both used to evaluate a Nile University building in Egypt in order to identify how the environment affects the results of each rating system. The results showed that each rating system has its own criteria in evaluating the sustainability level of the building, which are each based on the country's cultural and environmental conditions. © 2020 by the authors.