difference between new roof and replacement 20

https://nova-wiki.win/index.php/New_Roof_Construction_vs_Roof_Replacement:_What_Austin_Homeowners_Need_to_Know

Putting a new roof on that's never been there, like converting a porch into a sunroom, is much pricier because you're adding structure, not swapping. Replacing an existing roof, say after a storm, is simpler—just tear off the old shingles and nail on new ones. The core difference is building something fresh versus swapping out what's already there.