I have a domain that is a PR3. I am planning to give it a major overhaul, essentially starting it over from scratch. It's going to be over the same material. Will my pagerank suffer because of this?
Will suffer in case you change site topic and existing links will be devalued. You will keep PR if you stay on topic and links will remain relevant.
Same material, ok. As long as the inbound links do not drop because the content is no longer relevant. I don't see a problem. Why overhaul as opposed to adding more content?
You will lose your position in the SERPs and PR if you change your URLs. You can change the content and keep your PR, but the SERPs will change based on the new content, page titles, page descriptions, etc. You can do a 301 redirect from the old URLs to the new URLs to keep the link juice.
I had the site built a long time ago on a CMS I didn't like, and I have decided to re-design it from scratch. It will be a lot more user friendly, and make a good portfolio piece, imo.
Well Noway it would effect. Don't stress on PR much. There are many sites with PR 2 and outrank PR3 sites too. So u can go ahead and when u do keep in mind with the content and the keywords for which ur site ranked. Work on the same keywords + extra keywords too and optimize ur content much better than the earlier and u can really get much better than PR3. When u recreate u can use the same link structure + new keys too, but also do check for which keywords are ur site ranking and getting backlinks. Don't lose them. Work on Internal Link Structure Navigational Links Usability Make much easier and simple for Users Analysis ur site and keep on the research work with the keywords after updation Thanx