Reusing parts from an older site

Hi all, this is my first post!

I’m new to html/css coding and am currently redesigning a small business website for a family member.

My question is this: how much of the existing site’s code (just the html, css, js, php…it’s a pretty basic site) can I reuse for the redesign? Are there any copyright issues with that? While on the subject, what about other parts, such as images?

Also, another thing that may or may not be an issue: the previous developer who set it up used a theme (called diamond), which I’m assuming he purchased somewhere else. Would that make it any more complicated?

Thanks very much!

Depends on the copyrights involved. I would at least contact the designer and ask what would be involved in updating his site for the redesign. The inclusion of a possibly purchased theme ups the ante even more. The designer may not be able to give you permission to use the theme in the new design.

Thanks.

On a somewhat related note, what would rebuilding the site do to its search ranking? I plan on using different urls, except maybe for the index.

As long as you make sure to put in place 301 redirects from old to new pages, you should be OK.