Saadani Safari Lodge, Tanzania
At Saadani, you get safari and beach in one chic package. The lodge, in Saadani National Park, has nine tented cottages and six suites strung along the beach and shaded by casuarina pines. Hot water and electricity are provided by solar panels and the lodge has set up a water pump for the nearby fishing village. Most of the staff come from the village and the lodge owners make every effort to purchase goods from the community.
Saadani Safari Lodge, Saadani National Park, Tanzania (00 255 22 277 3294; saadanilodge.com). Doubles from US$490 (£327), full board.
Barefoot at Havelock, India
At this chic Andaman Island retreat, there's no need for chemical fertilisers and pesticides when you can use natural compost from your resident elephant. Barefoot at Havelock is made up of 18 thatched cottages and villas surrounded by tropical rainforest, behind a sweep of white powder-soft sand. As well as organic vegetables, guests can savour fresh fish and free-range chicken and eggs. The resort also harvests its own rainwater and is about to install solar power.
Manafiafy Beach and Rainforest Lodge, Madagascar
This English-owned lodge opened last year on the south-east coast of Madagascar. It is made up of six stylish cottages that are tucked among the trees just a few feet from a tranquil, sheltered bay. The lodge is powered by solar energy and the bungalows have been built using local wood, stone and ravinala thatch. A tree-planting programme is also under way.
Manafiafy Beach and Rainforest Lodge, Manafiafy, Madagascar (bookings through 01932 260618; manafiafy.com). Doubles start at €230, full board.
Steve and Lola scoured the coast for the right place to build their lodge. And this is it: a funky hideaway on Nanatha Bay. They established a marine reserve and built 12 chalets that use solar and wind power, as well as establishing community projects.
Nuarro Eco Lodge, Nampula Province, Mozambique (00 258 82 301 4294; nuarro.com). Doubles start at US$590 (£370) full board.
Pemba Lodge, Tanzania
This stylish retreat opened last year on remote Shamiani Island. The five bungalows are on stilts to capture the sea breeze and for minimum environmental impact. The showers use collected rainwater, and lighting is solar-powered.
Pemba Lodge, Shamiani, Tanzania (00 255 24 224 0494; pembalodge.com). Doubles start at US$440 (£273) full board, including transfers.
Kizingo is made up of eight bandas or cottages scattered along a glorious 12km beach on the southern tip of Lamu island. Solar panels provide electricity and hot water; wind cools the rooms instead of air conditioning. Add fund-raising for a local school and turtle conservation. and the credentials are impressive.
Kizingo, Lamu, Kenya (00 254 733 954770; kizingo.com). Doubles start at US$390 (£260), full board, including boat transfers.