From artificial reefs spawning new life, to sunken follies for the sake of submerging people to the seabed.

While buildings struggle to stay on top of rising water, there is plentiful evidence to suggest that letting them sink can be beneficial. Land- bound buildings have a history of utilising the thermal properties of water to increase human comfort, with techniques ranging from the positioning of vessels of water within a structure for thermal mass, to wrapping vertical structures around sunken ponds to generate thermal currents for natural ventilation.

It seems logical that floating houses would bed some of their rooms into their surrounding water to harness the mass of the ocean. A handy side effect would probably be an increase in fish numbers surrounding the structure. Ongoing US surveys have found fish densities are 20 to 50 times higher at artificial submerged oil platforms than in surrounding open water.

The high fish statistics on offshore oil rigs have spawned the US Government-led Rigs to Reefs program where decommissioned rigs are sunk to form artificial reefs. With more than 100 rigs made obsolete each year in the Gulf of Mexico alone, that’s a fair chunk of new reef. Closer to shore, disused train carriages and old tyres are commonly concrete-booted and dropped overboard.

Osbourne Reef, a tyre dump reef in Florida, demonstrates the downside of tyre dumping: In storms during the 1990s the submerged tyres broke free and rolled uphill, flattening a natural reef nearby. In Qatar ‘reef balls’ of cement and silica mimicking natural reef limestone are deployed in their hundreds to strengthen natural reefs. In a joint reef-building effort, Israel and Jordan are using Ocean Bricks, an architectural modular reef-building invention, to take pressure off the over-dived natural reefs of the Red Sea. Installed mid-2007, the fledgling reef has already 32 species of fish; half the number normally found there.

Hydropolis, Dubai

The vision of architect Joachim Hauser, Hydropolis houses 220 suites within a ‘submarine leisure complex’ 20 metres down – where else but dubai? originally scheduled for completion in december 2007, now delayed until 2009, hauser’s design references symbols of man and nature, but is sadly not powered by tide currents or waves. hauser’s press has proposed the hotel will draw attention to the degradation of coral reefs, but declined to provide detail on how his proposed 260-hectare footprint would affect the seabed.

Jules’ Undersea Lodge, Key Largo, Florida

The “first and only underwater hotel” lets you “visit inner space and experience what was once just a dream of science fiction writers” (jul.com). The underwater lodge can only be accessed by scuba diving 6.4 metres down and entering the lodge from below. Photographs of the interior show a sadly conventional, caravan-like reality. the complex also houses marine research labs.