1. Skanska: This Swedish developer is known for its focus on sustainable design and construction practices, including the use of renewable energy sources, green roofs, and waste reduction measures.

2. Lendlease: This Australian real estate company has made sustainability a top priority, with an emphasis on green building materials, energy efficiency, and eco-friendly practices.

3. Hines: This global developer has a longstanding commitment to sustainability, with an emphasis on LEED-certified buildings, renewable energy sources, and carbon-neutral operations.

4. Brookfield Asset Management: With a focus on sustainable real estate investment, this Canadian firm is committed to reducing environmental impacts through energy efficiency, green building materials, and other sustainable measures.

5. Forest City Realty Trust: This US company has made sustainability a core value, with a focus on LEED-certified buildings, green roofs, and energy-efficient technologies.

6. Grosvenor Group: This UK firm is known for its commitment to sustainable development, with a focus on reducing carbon emissions, promoting green transport options, and creating green spaces.

7. Gensler: This global design firm has a strong commitment to sustainability, with a focus on designing eco-friendly buildings that are energy-efficient and carbon-neutral.

8. Redevco: This European real estate company is committed to sustainable development, with a focus on reducing carbon emissions, promoting energy efficiency, and creating green spaces.

9. CBRE Group: This global real estate company has made sustainability a priority, with an emphasis on green building certifications, energy conservation measures, and sustainable operations.

10. Tishman Speyer: This US real estate developer is committed to sustainable development, with a focus on LEED-certified buildings, renewable energy sources, and green building materials.