It is an exclusive new development with superb sea views - and in a popular location.

Eastern Daily Press: Southwold water tower under refurbishment. Picture: Essex and Suffolk WaterSouthwold water tower under refurbishment. Picture: Essex and Suffolk Water (Image: Essex and Suffolk Water)

And those behind the 16 homes on Southwold water tower hope interested couples will - quite literally - flock to live there.

For the 16 houses are actually nest boxes for swifts. And conservationists are pumping out the birds' calls from wall-mounted speakers to turn what appears to be a flight of fancy into reality.

Experience has shown that playing calls during the months of June and July has proved successful at attracting the pairs of breeding birds, which have seen a significant decline in numbers acros the UK.

SOS Swifts volunteer Edward Jackson said they would be happy if one breeding pair settled into the new nesting sites this summer. 'It's a long term project and through this we're also trying to raise awareness and prevent loss of nesting sites.'

Eastern Daily Press: Edward Jackson from SOS Swifts with Essex and Suffolk Water's Oliver Rogers at the top of Southwold water tower. Picture: Essex and Suffolk WaterEdward Jackson from SOS Swifts with Essex and Suffolk Water's Oliver Rogers at the top of Southwold water tower. Picture: Essex and Suffolk Water (Image: Archant)

The number of breeding swifts in the country has almost halved between 1995 and 2015, placing the bird on the amber list of Birds of Conservation Concern. Conservation organisations believe that the decline is partly due to popular nesting sites in buildings being lost during renovations, as well as a halving in the number of insects – the staple food of the swift – since 1975.

If buildings are sealed or renovated, swifts may return to find their nest site has gone. They are cautious about entering new spaces for fear of predators.

Essex and Suffolk Water's contractor Stonbury carried out the work of installing the new nesting boxes while the tower was undergoing a £290,000 refurbishment. Alex Mueller, a conservation advisor, said research had shown that new nesting boxes that used the call broadcasting system had up to a 60pc success rate of attracting a mating pair of swifts.

The water company worked with SOS Swifts, a partnership between Suffolk Wildlife Trust and Suffolk Ornithologists' Group. Honorary president of the Suffolk Ornithologists' Group John Grant said: 'Swifts like to nest in small cracks and holes and on a water tower this might not be the best location for their homes.

We are keen for them to use the nesting boxes so there is no damage to our buildings and the swifts have a better place to bring up their chicks.'

The water tower is 26m and was built in 1937.