From old site to new without losing your rankings

Make a list of all existing addresses and note which get traffic from search engines, which produce enquiries and which other sites link to you. That list is your starting point: everything with value gets a place or a redirect on the new site.

Look too at what is not in the menu but does draw traffic: old blog posts, a page of frequently asked questions, a PDF that gets downloaded often. Those are exactly the pages that die in a rebuild.

Also record the current numbers: traffic per page, enquiries per month, the main search terms. Without a baseline you cannot see later whether things got better or worse.

Every old address gets exactly one new address through a permanent redirect. If a page disappears, point to the most related page — not to the home page. A redirect to the home page is treated as though the page no longer exists.

Watch for chains: address A pointing to B pointing to C costs speed and eventually breaks. Point straight to the final destination.

Keep what works, too. If an old page performs well, take that copy along and improve it instead of replacing it with something shorter and prettier. The temptation to rewrite everything is the most common reason traffic drops.

Beforehand: walk through every redirect, submit every form, run a crawler over the site for broken links, and check that the test environment is not itself indexed. That happens more often than you would think.

During: pick a quiet moment, keep the old site reachable until everything stands, and submit the new sitemap as soon as the site is live.

Afterwards: actively watch traffic and error reports. Fluctuation is normal; what you want to see is the most important pages keeping their traffic and no stream of errors coming in. If something drops, the cause is usually traceable in the list from step one.