The effect of the presence of thermal bridges related to roof insulation on annual energy consumption for two different climatic zones in Morocco

¹ Higher School of Technology, Ibn Zohr University, Laâyoune, Morocco
² Laboratory of Mechanics, Processes, Energy and Environment, National Schооl of Applied Sciences, Ibn Zоhr University, Morocco
³ Moulay Slimane University, Laboratory of Computer and Mathematical Process Engineering, ENSA Khouribga, Morocco

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 22 May 2026

Abstract

Since its putting into use in 2015, the Thermal Regulations for Construction in Morocco (RTCM) have defined six (related to the Earth's weather) zones and set consumption to be respected for each zone. In this study, we calculated the once-a-year energy needs of uninsulated buildings. We then studied the effect of roof insulation using two materials: expanded polystyrene and extruded polystyrene. Finally, we evaluated the thermal bridges effect on total energy use. The study focused on two zones: Zone 1, with a humid climate, and Zone 3, which is hot and dry one. The results show that uninsulated buildings remain acceptable in Zone 1 but far go beyond the limits set for Zone 3, where insulation becomes extremely important. Expanded polystyrene proved to be the most effective, reducing energy use by 67% in Zone 1 and 32% in Zone 3. In zone 1, thermal bridges result in a 6% increase in energy consumption; in zone 3, this increase rises to 13–16%. Overall, zone 1's difference with RTCM-required items is roughly 3%, while zone 3's is +33%. The overconsumption caused by thermal bridges ranges from 8.2% to 16.3% in zone 1 and from 13% to 16.3% in zone 3.