Here are some of the best eco‑friendly luxury residential projects / complexes in Kolkata (strong sustainability features, large green cover or formal green certifications). I’ve listed what makes each one “eco‑friendly” so you can compare quickly.

1. Uniworld City (Rajarhat / East Kolkata)

• Why: large open‑space ratio (~50–60% open space), on‑site sewage‑treatment plant (STP) with recycled water used for landscaping/flushing, waste‑segregation and low‑heat paver blocks for driveways. Strong community green practices. (infra.economictimes.indiatimes.com)

2. Lake District (East Kolkata / VIP Road corridor)

• Why: extensive planted/green areas (reported ~40% green coverage in parts of the complex), composting and community green initiatives, focus on retaining mature trees to reduce heat‑island effect. Good for buyers who want established greenery and eco‑sensitive landscaping. (greenkolkata.iamKolkata.co.in)

3. Forum Atmosphere (“Atmosphere”, EM Bypass / Topsia)

• Why: premium/luxury tower with high‑end planning and large shared amenity sky‑pod; while primarily a luxury landmark, it’s noted for design features that reduce footprint and incorporate large communal open spaces (suitable for residents wanting luxury plus better building design). (Check project site for latest green certifications.) (en.Wikipedia.org)

4. Godrej residential projects around Kolkata (examples: Godrej Prakriti, Godrej Se7en / Joka)

• Why: Godrej branded projects increasingly include wellness zoning, dedicated green pockets, landscaped central greens, and features such as rainwater harvesting / natural ventilation and wellness trails in newer launches—good balance of luxury and sustainability in newer suburbs. Verify individual project certification/status. (godrejregalpavilion.co)

5. Urban Greens (New Town / expanded suburbs)

• Why: masterplanned with a very high open‑space percentage (~60% in project messaging), cross‑ventilation/green views, large dedicated parkland and emphasis on reduced travel distances to daily needs (lower transport carbon). Good option if you want planned green layout plus modern amenities. (urbangreens.co.in)

6. Trayam (Peerless / New Town) — new green‑building project (announced)

• Why: Peerless’s mixed‑use Trayam project in New Town has IGBC Gold pre‑certification reported, and includes EV charging bays, rainwater harvesting, rooftop solar and a compactor — a new luxury mixed project explicitly designed for green performance. (Under construction — expected completion years out; check current status before buying.) (timesofindia.indiatimes.com)

7. Green Aastha (Amtala / Baruipur corridor)

• Why: marketed and awarded for sustainability (noted as “Best Eco‑Friendly Sustainable Project” in some listings), with features like natural ventilation, eco‑roofing, rainwater harvesting and EV charging. Good option in the suburban market for eco‑minded luxury buyers. Confirm on‑site inspections/certifications for final purchase. (Commonfloor.com)

Notes and next steps

• Certifications matter: IGBC / GRIHA / LEED certification (or even pre‑certification) is the best single indicator of measurable green performance — ask developers for the certificate and the level (e.g., IGBC Gold/Platinum). Recent projects like Trayam have reported IGBC pre‑certification. (timesofindia.indiatimes.com)
• On‑site features to verify when you visit: STP and how recycled water is used, rooftop solar capacity, EV‑charging provision, rainwater harvesting, building‑level energy efficiency (glass/wall insulation, LED lighting, HVAC standards), percentage of open/green space, and active waste‑management/composting programs. Local RWAs often run effective green programs in established complexes (Uniworld, Lake District). (infra.economictimes.indiatimes.com)
• Location tip: New Town (Rajarhat) is the fastest‑growing area for planned, green‑focused high‑end projects; older established complexes (Lake District, Uniworld) already have mature greenery and community systems in place. (timesofindia.indiatimes.com)

If you’d like, I can:

• Narrow this to a shortlist by neighborhood (New Town, EM Bypass, Southern suburbs), or
• Pull the most recent developer brochures / IGBC/GRIHA certification pages for 2–3 specific projects you’re most interested in (I’ll verify current certification and construction status).