Since 1980, global consumption of energy has nearly doubled. If current trends continue, that consumption rate would increase by another 85% by 2050. The built environment, which currently accounts for about one-third of total global energy usage, is expected to need double that amount by 2050.
Residential and commercial buildings also account for nearly 10% of energy-related carbon dioxide (CO2) emissions that most climate-change scientists connect directly to global warming trends.
So achieving international goals of reducing greenhouse gas emissions by between 80% and 95% within the next four decades is going to require not only tighter construction standards for new buildings, but also a more ambitious renovation of existing building stock than most countries are currently engaged in, according to a new report by the International Council of Chemical Associations (ICCA).
That report provides what it calls a “roadmap” to greater energy efficiency whose centerpiece, not surprisingly, is chemically derived building products including all types of wall and roof insulation, hot water piping materials, air barriers and air sealing materials, cool roofing, and windows.
Focusing on Europe, the U.S., and Japan, the report estimates that residential and commercial building stock in those countries and regions is expected to increase to 93 billion square meters in 2050 from 59 billion in 2000. Energy use over that period would grow by nearly 60%, and greenhouse gas emissions by 53% “if no improvements were made to the energy efficiency of new and existing buildings.” (The report does a separate analysis of the built environments in emerging economies such as China and India.)
Even if the envelopes of new buildings are made tighter through tougher codes and better construction practices, greenhouse gas emissions would still increase by nearly 10%. So ICCA sees the answer to reducing CO2 emissions to meet international targets in a more aggressive approach to making existing structures built after the year 2000 more energy efficient.
The report suggests that a “moderate” rate of renovation of those buildings would result in a 12% decrease in energy and greenhouse gases by 2050. “Tighter building standards combined with a more ambitious renovation rate could result in a 23% reduction in energy use and GHG compared to 2000.” (Those savings estimates are based on renovations improving the energy efficiency of the building envelope to 70% of the efficiency of new buildings in each decade.)
The report contends that chemically derived building products should be at the heart of these efforts. “By 2050, the greenhouse gas emissions savings attributed to these products is 970 MtCO2e [metric ton carbon dioxide equivalent] for the moderate renovation rate and over 1,100 MtCO2e for the ambitious renovation rate,” the report states. Use of energy-efficient plastic-frame windows alone adds another 300 to 370 MtCO2e of GHG savings, “where the chemically derived content of the window assembly plays a major role in the overall performance of the window.”
The complaint about chemically derived products has been that they require a lot of energy to manufacture, leaving a sizable carbon footprint. The report contends, though, that over time, the cumulative net greenhouse gas emission savings would be “many times greater” than the energy use and carbon impacts of producing these building materials.
ICCA also asserts it is “critically important” that all stakeholders in the building sector take actions to ensure maximum energy savings goals are met. These include:
•Providing incentives to increase renovation rates
•Harmonizing building standards and exchanging key information resources internationally
•Creating better awareness of the economic and social benefits of highly energy-efficient buildings, and
•Writing and regulating building codes in ways that don’t impede the use of energy-efficient chemically derived technologies.
John Caulfield is senior editor forBuilder magazine.
