The answer to the lack of natural gaps in the eaves of modern houses, is the swift brick – structural bricks which have an inner nesting chamber and an entrance hole. Below is a leaflet detailing their construction and use – take a look – it’s very interesting. We are trying to encourage all new builds to incorporate these. If you place your cursor on the document you can then scroll through the pages. These can be expanded with the + sign. If you click the black ‘pop-out’ button top right it will display at its origin on Google Drive and can be viewed or downloaded there.