The nest was made by Esschert Design (Homepage), and was about $25.00. Esschert is a wholesaler located in the Netherlands, and you can buy their products via Amazon. The nests are made out of concrete. I plan on adding additional ones, because more than one family shows up, but there is only the one nest. When the weather cools down and the birds leave, I'll clean the nest out. I also plan on putting up some ledges under the nests to catch the poop. They do make a mess.I was thinking that your swallows are much better engineers than the ones that come back every year to the overhang by our front door, then in following shots I see that you built a nest for them! I wonder if Kim would be upset if I made one for them for next season.
Each season one or two chicks inevitably fall out of the nest because the natural nest has filled almost to the brim over the years.