Windows, carpet chemicals, spray-foam, and LEED lawsuits: these are a few of your favorite things.

It's been a big year for green building. People are tightening up their buildings even as they tighten their belts. The retrofit market and multifamily housing have taken off in a big way in this new financial landscape.

The most-read Environmental Building News articles of 2011 reflect these new realities. Please check them out below and tell us in comments what you'd like us to cover in 2012! Don't forget that you can also get continuing education credits for reading many of these articles.

(NB: many of our most popular articles are available for BuildingGreen members only. You can check out affordable membership options here.)

10. Better Choices in Low-Slope Roofing.There are big differences in environmental impacts of commercial roofing materials, but the biggest variable may be service life.
9. Energy-Efficient Multifamily Housing. Now you can get LEED, Energy Star, and other labels for designing or retrofitting high-performance multifamily buildings.
8. The Chemicals in Our Carpets and Textiles. The array of water-, dirt-, and mold-repellent chemicals added to carpeting and fabrics is dizzying. Which are causes for concern, and how can we minimize exposure?
7. Measuring Energy Use in Buildings: Do Our Metrics Really Add Up? How much energy our buildings use matters a great deal, but figuring out how to measure that use and compare it from building to building is tricky. Here's a guide to key metrics and how to use them.
6. EPA Takes Action on Spray-Foam Health Risks. EPA takes another look at spray foam after increasing consumer health complaints. The action plan leaves open questions about how far EPA will go to clamp down on these products, but it's safe to think of this as a shot across the bow from EPA for the SPF industry.
5. New Plaintiffs Join Amended LEED Lawsuit. Instead of seeking to establish a broad class-action lawsuit representing building owners, taxpayers, and professionals harmed by LEED, the amended lawsuit focuses on the latter. The lawsuit was dismissed later in the year.
4. Re-Framing Sustainability: Green Structural Engineering. Want to design the greenest building possible? Get a handle on the best structural options available to you, and invite a creative structural engineer to join your team.
3. Solar Thermal Hot Water, Heating, and Cooling. By creating heat instead of electricity, solar thermal achieves three times the efficiency of photovoltaics at a lower price.
2. Making Windows Work Better. How to choose curtains, solar screens, awnings, and storm windows? The options are dizzying, but the right choice can cut energy bills.
1. Choosing Windows: Looking Through the Options. We ask a lot from windows: energy efficiency, aesthetics, durability, affordability, and more. Which window frame materials and low-e glazing options balance these choices best? This article explores all the options and decodes the performance labels we see when buying windows.