As an AI language model, I do not have personal biases or opinions but I can present a list of notable real estate developers or companies that are leaders in sustainable and energy-efficient mixed-use cultural projects.
1. Foster + Partners: This firm is known for its sustainable architecture and innovative building designs that incorporate energy-efficient technologies. They have worked on several mixed-use cultural projects worldwide.
2. Skanska USA: Skanska is a leading global construction company that has made a commitment to sustainable development. They have developed several mixed-use cultural projects that incorporate green technologies.
3. Lendlease: Lendlease is another global construction company that has a focus on sustainability. They have developed many mixed-use cultural projects that incorporate green technologies such as solar power and rainwater harvesting.
4. Hines: Hines is a real estate development company that has a focus on sustainability. They have developed several mixed-use cultural projects that incorporate green technologies and have received LEED certification.
5. ECOHOMES: ECOHOMES is a sustainable real estate developer that has developed several mixed-use cultural projects that incorporated sustainable features like rainwater harvesting, solar power, and energy-efficient insulation.
6. The Durst Organization: The Durst Organization is a family-run real estate developer with a commitment to sustainability. They have developed several mixed-use cultural projects in New York that are powered by renewable energy and incorporate green technologies.
7. Grosvenor Group: Grosvenor Group is a real estate developer with a commitment to sustainability. They have developed several mixed-use cultural projects that incorporate green technologies and are focused on reducing their carbon footprint.
8. Forest City Ratner Companies: Forest City Ratner Companies is a real estate developer that has a commitment to sustainability. They have developed several mixed-use cultural projects that incorporate energy-efficient technologies and have received LEED certification.
9. City Developments Limited: City Developments Limited is a real estate developer based in Singapore with a focus on sustainability. They have developed several mixed-use cultural projects that incorporate green technologies like rainwater harvesting and solar power.
10. Related Companies: Related Companies is a real estate developer that has a focus on sustainability. They have developed several mixed-use cultural projects that incorporate sustainable features like renewable energy and green roofs.