Thermal envelope retrofit: an assessment framework

Abstract

Generally, energy consumption in buildings has increased in the last 10 years by almost 95%, and with existing stock that is expected to have a long life; sustainable improvements to buildings should extend to existing buildings as well as new builds; retrofit should be embraced by developing an integrated decision to assess existing buildings’ conditions and to recommend an optimal set of sustainable retrofitting strategies. Energy consumption in office buildings is one of the highest compared to other building types; with an annual consumption that ranges between 100 and 1000kWh/m 2 depending on geographic location, use, type of office equipment, type of envelope, use of HVAC systems and type of lighting. Several factors could reduce the energy consumption in offices; such as passive design, energy conservation plans, water management systems, controlled lighting systems, use of renewable energy, limited use of active air conditioning system and building envelope improvements. This paper aims at developing an assessment and retrofit strategy for improving the energy performance of offices with focus on the building’s envelope which with careful design could reduce energy consumption and carbon footprint by up to 15%. The paper starts by exploring the features of the building envelope, and how they impact energy consumption, in addition to suitable retrofit systems. Both envelope elements and retrofit systems formulate a framework; which is then applied to an office building in Alexandria, Egypt as a case-study.