The existing residential building stock accounts for a substantial portion of worldwide energy consumption and greenhouse emissions. Improvements to the thermal performance of existing buildings is a vital activity to mitigate climate change, and often has additional benefits in the form of improved comfort, health and well-being for occupants. Despite the extensive body of literature in this area, it remains a difficult task to assess the performance of retrofit packages in occupied residential buildings.

Over half of the population of the world live in
urban areas. This means that efforts to meet human
development goals and sustain economic growth
must be concentrated in cities. However, the pursuit
of more prosperous, inclusive and sustainable urban
development is complicated by climate change, which
multiplies existing environmental risks, undermines the
effectiveness of existing infrastructure, and creates new
resource constraints.
In this paper, we conclusively demonstrate that there

Cost savings from efficiency gains are at the core of the green building business case. Significantly lower energy bills are said to be a major factor in the green rent premium observed in earlier studies. Our study tests this relationship by inferring energy costs from operating expenses for a large dataset of U.S. office buildings and relating them to rental rates. We find that eco-certification is associated with a higher than anticipated total energy expenditure, which is the opposite of its expected effect.