Below is a curated list of widely recognized sustainable boutique hotels across Sri Lanka (small or design-forward properties with demonstrable environmental and community practices). For each I note the key sustainability highlights and the location — I’ve cited reliable sources for the sustainability claims so you can read details and verify current programs before booking.

Top sustainable boutique hotels in Sri Lanka

1. Jetwing Vil Uyana — Sigiriya

• Why it’s sustainable: built around a restored/artificial wetland (paddy/ marsh/forest mosaic), strong water-recycling and biodiversity programs, long‑running community training initiatives. (en.wikipedia.org)

2. Heritance Kandalama — Dambulla / near Sigiriya

• Why: Geoffrey Bawa–designed property noted for minimal-impact siting (built into the cliff without tree‑clearing), rainwater harvesting, energy‑ and water‑saving systems and ongoing community programs. (cahayaharamain.com)

3. Ulagalla by Uga Escapes (Uga Ulagalla) — Anuradhapura / Thirappane

• Why: low‑impact private‑villa concept on conserved land; the Uga group emphasizes on‑site organic farming, solar and water‑treatment systems and wildlife-friendly operations across its properties. (brandradar.org)

4. Chena Huts by Uga Escapes — Yala coast / Tissamaharama

• Why: small-scale, nature‑integrated huts with wildlife-friendly policies, low-impact design and community engagement tied to conservation near national parks. (brandradar.org)

5. Santani Wellness Resort — Kandy foothills

• Why: wellness resort built to reduce energy needs (natural ventilation/design), advanced water recycling and gardens/organic produce used in the kitchen; focus on low-impact construction and guest education. (brandradar.org)

6. Amanwella (Aman Resorts) — Tangalle / southern coast

• Why: Aman’s property-level sustainability measures typically include organic gardens, beach and marine conservation efforts, reduced single‑use plastics, LED/energy measures and community programs (Aman publishes resort-level initiatives). Confirm details with the resort. (koretraveler.com)

7. Abode Ahangama — Ahangama / southern coast

• Why: small boutique property emphasizing local materials and indigenous construction methods, natural ventilation and community/ beach‑cleanup initiatives. (bytheboutique.com)

8. The Kandy House — Kandy

• Why: heritage‑restoration boutique that conserves a historic property and surrounding gardens; smaller scale and locally‑focused sourcing and cultural conservation. (Heritage conservation + boutique model.) (thetimes.co.uk)

9. Jetwing Lagoon / Jetwing Yala (other Jetwing eco properties)

• Why: Jetwing group operates several properties with visible sustainability tech (biomass boilers, large private solar installations, wastewater reuse, community programs); good options if you prefer a trusted local operator with documented green projects. (jetwinghotels.com)

10. Smaller eco‑lodges and independent ecolodges (examples to search/consider)

• Examples often recommended: small ecolodges near Polonnaruwa/Anuradhapura and low‑impact beach hideaways in the south. Many are family‑run and prioritize community employment, reef/ beach protection, and low‑energy design — check recent guest reviews and certification/awards before booking. (See eco‑hotel roundups). (cahayaharamain.com)

Booking / verification tips

• Ask the hotel for specifics: percentage of energy from renewables, water‑treatment and reuse systems, single‑use plastic policy, on‑site waste separation/composting, and community/employment programs. If they claim certification (Green Globe, EarthCheck, Travelife), request proof or a link.
• Check recent reputable travel press or recent guest reviews for evidence the programs are active (some initiatives can change). Condé Nast, National Geographic, and major travel outlets sometimes highlight hotels with active conservation projects. (en.wikipedia.org)
• For wildlife areas (Yala, Sigiriya), prioritize small‑scale lodges that enforce responsible wildlife viewing and work with park conservation authorities.

If you’d like, I can:

• Narrow this to a specific region (south coast, Cultural Triangle, Kandy) or travel dates and find the latest guest‑verified sustainable options and current awards/certifications; or
• Build a 7–10 day “sustainable boutique” Sri Lanka itinerary linking 2–4 of these properties.

Which would you prefer?