Droppings
Sometimes birds nesting on buildings can cause problems for the buildings residents. The usual complaint is the mess left at the entrance to the nest by droppings. Depending on the location and height of the nest this can usually be solved by fixing a shelf under the nest to catch the droppings.
The droppings are usually concentrated to a specific area under the nest as the young birds move to the edge of the nest to deposit their droppings. This problem can be easily solved with a small shelf placed in this area (which is then cleaned seasonally). It has also been shown that the excrement from insectivorous birds is a good fertilizer for plants. You could collect the droppings from the shelf and add them to the plants in your patio.
A simple shelf can solve a problem and allow swallows and house martins to continue eating the mosquitoes that bite you. And on top of that leave you with thriving plants in your patio!
When a bird makes a nest in an inconvenient place.
It is hard to see a nesting bird as nuisance, from the perspective of someone who loves birds. Sometimes it is about re-framing our thinking. Is it really a problem? Can I live with a temporary inconvenience until the birds have migrated? Is there curiosity to observe their behaviours? Is it educational for my children?
The quandaries of modern life mean that half of the internet is full of how to attract birds to nest or how to make artificial nests and another half that provides a multitude of torturous means to get rid of them. In Spain taking down the nests of swallows, house martins and swifts is illegal. You need special permission to remove nests and could be liable for a big fine if you remove the nests without permission.
Can you add to the debate? Have you found creative solutions to living with nesting birds?