Moving new development in sub directory to superceed current site

I am asking this for a client who i will be giving access to see the responses as this is important for him to know what advice the web development commmunity has on this subject.

My client has a website that is SEO’d properly, analytics are running and he is happy with the performance and does not want to lose anything with regards to that. We have been developing a new site with a new template, different pages etc in a sub directory. The time has now come to remove the old website and insert the new site with its streamlined structure (pages and design) from the sub directory to the root. How can this be achieved without losing any of the performance the old site has.

I have mentioned 301 redirects but my client would like more alternatives to this

Many thanks in advance

Yep redirects.

Check the Google page score of each old page compared to the new page. Try to get better values on all the new ones. Make sure new ones don’t load slower.

Check meta tags and important unique content is not lost.

Keep an eye on Google webmaster tools after the change. Or even use some of the webmaster tools to submit/check the new pages are good to go

the old site has been going for a few years and therefore its time for a design overhaul and a restructuring of pages/posts. So it seems redirects are the way to go then. just for arguments sake can you tell me why deleting the old site and inserting the new site wont work as well even if we keep the same keywords (expand on present ones) and use the same analytics ID?

since the consensus is redirects it is probably a good idea to make sure that the sub directory name is something meaningful rather than /ver2/ or something of that ilk.

thanks in advance