BATM / Bat Mansion


The Muz Yer project in Rennes asked different architects to design birdhouses on various locations throughout the city. Each birdhouse is a specific architectural response to an urban context and a refuge specific to the species identified by the Ligue Protectrice des Oiseaux (RSPB in France), the project’s scientific partner.

The project of JDS Architects is situated in the Parc Des Gayeulles, near the park’s lakes and forest areas. Instead of making a house for birds, JDSA decided to tackle the ‘mal aimé’ flying species: the bats! Looking at the site, it is a naturally good habitat for bats, with one thing that’s lacking: a house to stay in. In the forest, grass and wetland park, optimal natural environments for bats to nest and seek shelter are limited, so installing a Bat Mansion in the area is very meaningful.
Bats are an important part of a functioning ecosystem. Making a bat-friendly place supports the essential role bats have in the environment, including pest-control, pollination and seed dispersal.
The design of the Bat Mansion comes forth from thorough research on bats’ nesting needs. They need a landing area from which they can climb up, typically roughened wood. Once up, they are able to migrate from chamber to chamber, which they will do according to crowdedness and temperature. Bats don’t like cold.

The different landing platforms are positioned stepping up outwards and all around the central mast, with a large door on the (colder) northside for occasional maintenance, such as a thorough guano clean up once in a while.
More interventions to make this wooden Bat Mansion a warm and cosy bat attracting place, are the thick, insulated, sedum roof, to prevent heat loss from, and that the outside layer of wood is charred black, so that even the least amount of sunlight can have a warming effect.