I'm thinking about overhauling my main site. I'll leave all the content and link structure the same but will add a new design. It will probably increase the size of the pages and will move around the HTML but as far as content and url structure it will be exactly the same.
My question is has anyone done this and seen a negative effect from the search engines. This site pays my bills and I know after all the fluctuations are done it will look better and be overall better for my readers. I just want to know if I'm going to loose a months revenue here or what.
So if anyone has had any experience with this as I'm sure someone has to or knows of a good article it would be much appreciated.
If you limited design changes to pure design (i.e., CSS) and left everything else alone there should be no ranking impact at all. Minor site maintenance shouldn't really make much difference. If you were very concerned you might want to consider testing out the new design elements on a limited set of pages and wait a few months to see what the impact might be.
If you make changes to your site template you can expect Google to drop some pages temporarily. They're lighting quick at filtering out pages that have changed. Don't stress about it, I've done this dozens of times for clients and as long as the textual data remains the same and the new template isn't loaded with new links the rankings hold.
If the new template has different links in areas like the footer, pointing to different designers etc, consider adding nofollow to them.
edit: by drop I mean completely removed from the serps, not usually longer than 48 hours and not all pages.
[edited by: JS_Harris at 10:21 am (utc) on Mar. 16, 2009]