Energy consumption reduction using sustainable building envelopes' material in school buildings

The building sector is one of the highest energy consumption sectors, along with industry and transportation. For instance, in the U.S., buildings are the main energy consumers, as they represent 39% of the total primary energy consumption, and in Canada they represent 30%, compared to other sectors. Educational buildings in the U.S. and Canada spend approximately U.S. $16 billion on energy consumption every year. This high consumption is due to the current number of establishments, the growth in the number of schools across these countries, and their inappropriate selection of building envelope types. A reduction in energy consumption will help to reduce the overall life cycle costs incurred by governments, as well as reducing environmental impacts. This paper discusses the selection of the most sustainable material and envelope types for school buildings. Four different envelope types are investigated: concrete, steel, masonry, and wood, evaluated for their energy performance and sustainability level using the (LEED®) scoring system. A prototype model of a 250,000 ft ² high school building in Montreal is tested using energy simulation software (eQUEST), and an energy design guide is applied for K-12 school buildings. This guide was developed using ANSI/IESNA/ASHRAE Standard 90.1-1999. Three different test scenarios are applied to each of the following envelope types: no insulation at all, minimum code requirement for the climate zone, and the ASHRAE advanced energy design guide recommendations. The results show that the concrete and masonry envelopes can reduce energy consumption by 21% and 20%, respectively, up to 32%, while the steel and wooden envelopes reduce the consumption by 13.5% and 15%, respectively, up to 32% over the ASHRAE standard baseline. Six to eleven LEED® points can be achieved when a concrete envelope is applied, while two to eleven points can be obtained when a steel envelope is applied, depending on the test scenario.