In the USA, buildings consume about 39% of the primary energy and represent 38% of CO2 emissions.
In this context, this article shows a table with some energy-efficient strategies (for e.g. more airtight building envelopes, reduced outdoor air ventilation rate, low energy cooling systems, no air conditioning, ...), together with their potential impacts on the indoor environment quality (IEQ - covering indoor air quality, thermal comfort, acoustics,...) and their consequences on the HVAC systems design. The author points out the needs for technology improvements to reduce energy use while maintaining good indoor environment.
ASHRAE Journal - Vol. 51, N°6 - June 2009 - pages 22-23