Dear Colleagues,

This Special Issue seeks to collect new and proven technologies, policies, and financing mechanisms to improve energy efficiency and capture cost-effective energy savings in buildings, and to present the latest research results on energy efficiency measures, and how they can be introduced and financed. Further findings and examples from successful technologies, programs, and schemes that have been introduced worldwide will also be highlighted.

About one-third of global energy is consumed in residential, public, and commercial buildings, where it is used for space heating, cooling, ventilating, lighting, cooking, water heating, refrigerating, and operating electric and mechanical devices. Global energy use in buildings is expected to grow as developing countries continue to modernize and per capita income levels continue to increase. Due to their high energy consumption, residential, public, and commercial buildings also offer unparalleled opportunities for energy savings. According to the International Energy Agency, buildings will account for approximately 41 percent of global energy savings potential by 2035, compared with the industrial sector (24 percent) and the transport sector (21 percent).

There are three primary ways in which energy efficiency can be improved in residential, public, and commercial buildings:

1. Through improved design and construction techniques that reduce heating, cooling, ventilating, and lighting loads;
2. Through building upgrades and the replacement of energy-using equipment, including local energy production, e.g., solar panels;
3. By actively managing energy use.

The main opportunities in which energy efficiency interventions can be launched are as follows:

• When designing and constructing new buildings.

A building energy efficiency code sets out the minimum energy efficiency requirements of a building, including the thermal performance of a building’s “envelope” and the energy efficiency standards of its internal equipment and devices.

• By retrofitting existing buildings.

Retrofitting existing buildings and replacing energy-consuming equipment are critical for improving energy efficiency in cities where building stock turnover is low. Municipalities need to capture this potential by incentivizing and/or implementing energy efficiency upgrades as part of all significant renovations and equipment-replacement activities. For this to happen, a suitable environment and effective project financing and delivery mechanisms must be in place.

• By establishing and maintaining energy management systems.

Establishing and maintaining effective energy management systems for monitoring and controlling energy use in large public and commercial buildings is a low-cost means by which to improve energy efficiency and reduce energy demand.

There are a number of key barriers that must be overcome in order to improve energy efficiency in buildings. These include the high cost of gathering reliable information on a building’s energy performance; the lack of technical capacity with which to design, construct, and maintain energy efficient buildings; the lack of incentive to invest in energy efficiency above the minimum building code level; limited access to financing; and difficulties in coordinating the building sector’s many stakeholders. Some barriers to greater EE are specific to certain stakeholder groups. For example, high transaction costs relative to returns and the perceived unreliability of repayment often deter commercial banks from financing EE building projects. Other barriers are sectorwide, such as energy subsidies and/or a widespread lack of data and information on EE opportunities, costs, and benefits. Addressing systemic problems such as these typically requires policy interventions and support at the national and regional levels, although municipal governments can be influential in policy design and implementation. A different kind of barrier is the strong focus on advanced (and expensive) technical solutions for retrofitting solutions in research and demonstration projects. Practitioners have difficulty using output from this kind of research in their daily work. The aim of this Special Issue is to collect suggestions for overcoming these barriers, e.g., strong commitment and leadership from authorities as well as a willingness to work closely with national and regional governments, building and home owners, developers, financiers, building trades and industries, and energy utilities.

With regard to investigating the potential to systematically improve energy efficiency in buildings, the topics of interest for this Special Issue include, but are not limited to, the following:

• The identification of key opportunities and challenges, assessment of stakeholders and resources, and determination of priorities and next steps;
• Rapid energy efficiency assessment of the building sector;
• Emphasis on public leadership by showing the most promising examples of implementing energy efficiency initiatives in public buildings—such as municipal offices, schools, and hospitals;
• How to initiate energy efficiency programs for residential and commercial buildings by utilizing the expertise and resources of key stakeholders—building owners, energy utilities, national and regional governments, and international donors.

Prof. Dr. Matthias Haase
Dr. Petter Wallentén
Guest Editors

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• energy efficiency assessment
• energy efficiency markets
• energy efficiency planning
• deep energy retrofit
• municipal procurement
• sustainable development