Building Operating Management, Apr. 2017, by David Park
http://www.facilitiesnet.com/energyefficiency/article/How-Existing-Buildings-Are-Moving-Toward-Net-Zero-Energy--17111

An article in 4-parts:
Part 1: How Existing Buildings Are Moving Toward Net Zero Energy
Part 2: Deep Energy Retrofits: First Step Toward Zero Energy Existing Buildings
Part 3: How To Use Renewable Energy To Achieve Zero Energy Existing Buildings
Part 4: Retail Chains Embrace Solar: Total of More Than 1 Gigawatt of Installed Solar