What a website rebuild can cost you in Google and AI answers

Why do Google rankings fall after a new website goes live?

Mostly because old page addresses stop working. Google has years of signals attached to your existing URLs, and when a rebuild changes those URLs without a permanent redirect, the old pages return errors and the new ones start with nothing.

Take a made-up valve maker whose page for a 50 mm ball valve has lived at /products/ball-valve-50mm.html since 2015. The new site puts it at /valves/ball-valves/50-mm/. Unless the server sends a 301 redirect from the first address to the second, a buyer clicking the old Google result, a dealer link or a directory listing lands on a "page not found" message.

Google's guide to a site move with URL changes is clear on the method: use server-side permanent redirects, send each old URL straight to its new equivalent without chains, and keep the redirects for generally at least a year. It also warns against sending many old pages to one unrelated page such as the new homepage. Its redirects documentation explains why: a permanent redirect (301 or 308) tells Google the new address should replace the old one in results, while a temporary one (302 or 307) keeps the old address in place.

Even when everything is done right, Google says to expect temporary fluctuation in rankings, and a few weeks or more before a medium-sized site's new URLs start to show. That is the cost of a well-run site migration.

What should the redirect map contain?

Every old URL that has ever mattered, paired with its new address, in a spreadsheet the owner can see. Google suggests building the old list from sitemaps, server logs, analytics and the content system itself, and including embedded files such as images and videos.

Downloads are easy to forget. Catalogue PDFs, datasheets and test certificates get linked from dealer websites, tender documents and directory listings, and a rebuild that moves them to a new folder breaks every one of those links. Ask for four columns: old URL, new URL, redirect type, and a "tested" column filled in after launch. Pages you are genuinely dropping should return a 404 or 410, not a redirect to the homepage.

Can the enquiry form break without anyone noticing?

Yes, and because the failure is silent it can cost weeks of enquiries. The new form may be tested by the developer sending a message to his own address, then go live still pointing there, or the mail settings on the new server may push enquiries into spam.

The same goes for click-to-call numbers, WhatsApp buttons, the "download catalogue" form and any dealer enquiry form. After launch, someone from your sales team should submit a real test enquiry from every form on a mobile phone and confirm it reached the right inbox. If enquiries only ever exist as emails, there is no record to check against; EbizIndia's note on enquiries lost in an inbox and never counted covers why saving each one, with its product and source, makes this kind of failure visible.

What happens to analytics and Search Console?

Both can go dark on launch day. Google Analytics only records visits on pages that carry its tag, and new templates are often built without it, or without the events that count form submissions. The gap may only show up weeks later, as a drop in the traffic report that is not real.

Search Console is more fragile than most owners realise. If the site was verified with an HTML file or a meta tag, and the rebuild removes it, Google's ownership verification help page says Search Console checks periodically and permissions expire after a grace period. Verification through a DNS record sits with the domain rather than the web server, so a rebuild does not touch it as long as the record stays in place, which is one reason to prefer it. After launch, submit the new sitemap and watch the indexing and performance reports. Search Console's Change of Address tool is only needed if the domain itself changes.

Do structured data and AI answers suffer too?

They can. Structured data, the code that tells Google your company name, logo, address and products, lives in the old templates. A new theme often leaves it behind unless someone asks, and the sameAs links that tie your website to your LinkedIn page, directory profiles and other official records go with it. Google's Rich Results Test or the Schema Markup Validator will show whether the new pages still have it.

AI assistants describe your company from pages they have already read. If the new product pages are lighter on specifications than the old ones, or the capacity and approvals move from text into an image or PDF, assistants have less to quote and keep relying on older copies elsewhere. Run the same set of questions before and after launch, using the method in how to check what AI assistants say about your company, and compare.

Who is responsible for each item?

Someone by name, written into the contract or brief. These jobs tend to fall between the developer, the agency and your own sales team, and an item with no name against it is easily missed.

Most of this belongs in the brief before any design work starts. The one-page rebuild brief has a "what must not break" section for exactly this list, and if you are still deciding whether a rebuild is needed at all, read when to rebuild a website and when to repair it. The rest of the website rebuilds section covers product pages and quote forms on the new site.