New construction in appropriate locations should aim to incorporate nest sites and there are some off-the-peg solutions. Pre-fabricated nest boxes are available in a variety of shapes and sizes – not all of them suitable!
One problem with the Swegler woodcrete box is that the 55mm high entrance makes it available to starlings.
A web search for "swift nest boxes" will show you a large variety of possibilities. The problem remains to choose the most suitable and appropriate – not necessarily the easiest!