Bird nesting opportunity
Tom Spriggs Architect Ltd has developed a practical approach to incorporating bird nesting spaces into the fabric of residential buildings. The idea was developed before repair works took place to the roof edge of a Victorian house in Exeter, where several sparrows had been nesting within gaps formed by decaying timber. There are numerous off-the-shelf integrated bird boxes on the market, and several designs for nest opportunities in eaves. The off-the-shelf products are typically to be built into the brickwork walls which can be problematic if there is an insulated cavity, or hard-to-match colour/appearance. Here a verge was being repaired, which is the roof edge on a gable, the sloped edge of a roof, not the eaves, where the guttering is.
Rather than sealing these openings the project sought to preserve and enhance the site’s nesting opportunities by integrating nest boxes into the refurbished roof edge.
The loss of natural nesting opportunities is an ever increasing problem as buildings are sealed up, particularly with pvc soffits and eaves that commonly finish tight against the building, finished with capping pieces and sealant. In response, this project introduces intentional access points within a newly constructed section of the roof, allowing birds to nest without compromising the building’s performance or the comfort of its occupants. The nest boxes are effectively ‘outside’ the building thermal envelope, but protected by the over sailing roof.
Initial sketch proposals were developed and refined in collaboration with local ecologist Colin Wills, whose input helped optimise the design’s practicality and suitability. The resulting solution is both simple and effective.
A deeper roof overhang has been introduced to better protect the wall below from heavy rain, with slates and roof felt extended over. Within the soffit (the underside of the overhang) a series of holes provide access to individual nesting chambers. The timber framework creates a ladder-like structure tied back to the existing rafters, dividing the length into appropriately sized nesting boxes. By forming the access holes in the soffit, each nest is protected from rain ingress and the structural timbers stay dry.
PVC was selected for the exposed external elements due to the difficulty of safely accessing this height for maintenance, with timber forming the internal nest box offering insulation and a more natural habitat.
They have been in place for a few months now after being installed during the winter and several birds are already preparing for spring in them. Tom is keen to roll out the now proven design to as many projects as possible, and is keen for others to adopt it to improve urban biodiversity and opportunities.
