Start at the roof edge
Map where the roof sheds water. Valleys and long roof runs can concentrate flow, so gutter size and downspout placement should follow the drainage demand rather than a single standard profile.
Decide where the water should go
A downspout needs a discharge plan. Discuss walkways, planting beds, neighboring property, and the foundation. Moving water off the roof is only half the job.
Match the house, not just the color
Profiles, hangers, and downspout shapes affect the appearance. Ask how the gutter will meet fascia and roof-edge details, and whether existing wood needs repair first.
Leave room for maintenance
Trees, roof geometry, and access affect cleaning needs. Guards can change maintenance requirements, but do not make every gutter maintenance-free.
Make it specific to your home.
This is general planning information, not a diagnosis, quotation, insurance determination, or promise of product performance. A property-specific assessment and written scope are the next steps.