Most of the time we are redesigning a website because it isn’t ranking in Google. However if you are ranking with Google, it doesn’t mean you are stuck with your website design forever.
[button url=”http://support.google.com/webmasters/bin/answer.py?hl=en&answer=83105″ style=”button” size=”small” type=”” target=”_self”]Moving Site in Google[/button]
The answer to moving sites, whether the site is redesigned, or the site is moving entire domains, is to setup 301 redirects. 301 redirects are the approved and preferred model that Google uses to permanently associate the old page with the new page. They are server side pointers that redirect the incoming page requests to the new source and Google listens to them.
[blockquote]Google says: “If you need to change the URL of a page as it is shown in search engine results, we recommended that you use a server-side 301 redirect. This is the best way to ensure that users and search engines are directed to the correct page.”[/blockquote]
301 is a permanent redirection, but it is recommended that you maintain both sites for 180 days.
All of this and you still have to retain an amount of common sense. If you are removing a page and redirecting it to a page of no relevance of the original, Google will notice. Most people also experience a lapse in ranking for a couple weeks after the initial change.