Redesign or rebuild: telling which one you need
'The site looks dated, let's redo everything' is usually a feeling rather than a finding — and an expensive mistake in either direction.
The difference
A redesign updates appearance and page structure on the existing platform: CMS, URLs and content largely stay.
A rebuild means a new platform and architecture, often new URLs and reworked content — a different scope, timeline and level of risk to organic traffic.
When a redesign is enough
The site is technically sound and fast, content is manageable and integrations work, but it looks dated or does not reflect new positioning.
It also fits when the problem is conversion rather than technology: unclear navigation, weak calls to action, overloaded forms.
Deciding, and what to protect
Gather data — speed, user behaviour, per-page conversion, organic traffic, technical constraints. Interface problems mean redesign; foundation problems mean rebuild.
Either way protect the SEO inheritance: inventory every URL, 301-redirect old addresses, carry over text with its key phrasing. The usual post-rebuild traffic loss is not bad design but hundreds of 404s.