I looks good. Bird houses are fun, to build and watch the birds. I do't have Purple Martins in my are but we have Tree Swallows which prefer individual housing so I have about 18 houses scattered around my property. Which reminds me it is time to clean and inspect them. The swallows return here in mid March along with the robins, buzzards and humming birds.
Does that qualify for a tax break as low income housing? LOL