Action for Swifts: The Cambridge System with circular entrance pieces

This is a nice implementation of the Cambridge System with circular entrance pieces

Thanks for the pictures are due to Graham Fry, who lives near St Neots.

With rendered walls, one cannot see where the bricks are in order to go about removing a brick to make an entrance. While one could tackle the problem from the inside, one risks making a mess of the render. So making a hole with a 4 inch core drill from the outside is another way of doing it. Then circular entrance pieces neatly fill the hole.

This is a solid wall 9 inches thick, but a 4 inch core drill is an efficient way to make a hole all of the way through.