An environmental impact assessment of the site produced a record of Great Crested Newt. However, in consultation with Haddenham Conservation Society, a provision was written into the recommendations written by the eco-consultants, MLM, and subsequently into the planning approval requesting the installation of nestbox accommodation for bird species known to nest in buildings. In the event, this meant primarily Swifts.
Jake Allsop and Dick Newell of Action for Swifts, visited the site and had constructive talks with the building contractors, T J Evers. We offered them a simple solution: to incorporate nestboxes made from clay airbrick liners inside the brickwork of the buildings, concealed behind slip bricks (a ~1 inch slice of brick) with an entrance cut in it, in most cases on the gable end. This is a low cost solution, and easy for the bricklayers to implement. [We have used clay airbrick liners on other projects here and here]
|Example of a finished entrance|
|Unfinished nest-box, showing the exposed|
airbrick liner before covering with slip bricks
We learned something on this project: The size of the access hole to the nest cavity is critical. The recommended dimensions are Length 65-70mm, Height 30mm, but we know that at 30mm, Starlings can squeeze in, so we recommended a height of 28mm (tolerance 27mm-29mm). (Swifts will get into a hole as low as 25mm, but as they wriggle to get in, they may be vulnerable to predators).
In the event, there was some variation in the size of access holes, which is understandable. It suggests that in future, the boxes and their entrances should be pre-fabricated.
The building contractors were entirely enthusiastic and supportive, and it is to be hoped that they will take the message with them to future housing developments that they work on. We also hope that the message from Northumbria Close Haddenham will be heard by other developers across the land. It's the only way we can be sure that there will be Swifts in our skies in years to come.