Somewhere around month eighteen, every founder gets the same itch: the site looks tired, a competitor just launched something shinier, and surely a rebuild will fix the flat lead numbers. Before you brief an agency on a full website redesign, though, it's worth asking a blunter question. Is the site actually broken, or is it just old? Those are two very different problems, and only one of them needs £8,000 and six weeks.
This is the framework we run every client through first. It takes about twenty minutes and it usually saves people from redesigning a page that was never the issue.
Start With What's Actually Broken
A redesign fixes a site that confuses or repels visitors. Optimization fixes a site that undersells itself to the right ones. Confusing the two is the single most expensive mistake in this whole decision.
Pull three numbers before you decide anything. Bounce rate on your key pages: above 70% on a page that should be converting is a real signal. Average time on page: under twenty seconds usually means people can't tell what you do. And your conversion rate against a realistic benchmark, which for most B2B service sites sits somewhere between 2% and 5%. If all three are ugly, you likely have a structural problem. If just one is off, you probably have a smaller, fixable one.
The Five Questions That Actually Decide It
Skip the vibes-based debate about whether the homepage "feels dated." Answer these instead.
One: can a stranger explain what you do after five seconds on the homepage? If a friend outside your industry can't, no amount of copy tweaking saves it; that's a redesign-level fix to the hierarchy and messaging.
Two: is the site built on something you can no longer safely update? An ancient WordPress theme with twelve unmaintained plugins, or a page builder nobody on the team understands anymore, is technical debt rather than an optimization problem, and it compounds. Every month you wait, it gets more expensive to touch.
Three: does the traffic exist but the leads don't? This is the important one. If SEO or paid traffic is landing on the page and just bouncing, you don't need a new site. You need a sharper page. We've fixed this on client sites in a week by rewriting one hero section and cutting a form from seven fields to three.
Four: is the brand itself out of date, not just the site? If you've repositioned, changed your offer, or moved upmarket since the current site was built, the site is now lying about who you are. That's structural. Rebuild it.
Five: what's the actual cost of waiting? A tired-looking site that still converts decently is a cosmetic annoyance. A site quietly losing 30% of its qualified traffic to a confusing nav is bleeding pipeline every single day you leave it alone.
If you answered "structural" to two or more of the five, you're in redesign territory. One or none, and optimization will get you most of the way there for a fraction of the cost.
What Optimization Actually Fixes (And What It Can't)
Optimization is targeted. It's the landing page hero rewrite, the form-field cut, the trust-signal reorder, the page-speed fix that shaves two seconds off load time. It's cheap, fast, and it compounds when you run it every quarter instead of once every three years.
But optimization can't fix a fundamentally wrong information architecture. It can't fix a brand that no longer matches the business. And it can't fix a codebase so brittle that every small change breaks something else. Trying to optimize your way out of those problems is how agencies end up billing hours to patch a leaking roof instead of just replacing it.
What A Redesign Actually Costs (Beyond The Invoice)
The invoice is the easy part to budget for. The part people underestimate is the six to twelve weeks where your marketing engine runs on an old site while a new one gets built, and then the month after launch where SEO rankings often dip before they recover, because Google needs time to re-crawl and re-trust the new structure.
A redesign done badly loses you rankings, resets your analytics baseline, and confuses your sales team mid-cycle. A redesign done well, with 301 redirects mapped, content migrated with intent, and tracking rebuilt before launch day, avoids most of that. The difference between those two outcomes is almost entirely in the planning, not the design.
What The Budget Actually Looks Like
Founders rarely compare the real numbers side by side, which is part of why redesign wins the argument by default. A proper optimization sprint, the kind that touches your top three pages, rewrites headlines, cuts forms, and fixes obvious speed issues, typically runs somewhere between £1,500 and £4,000 and takes two to three weeks.
A full redesign for a mid-sized B2B services site, done properly with UX research, copywriting, and a redirect plan, lands closer to £8,000 to £20,000 and takes six to twelve weeks, sometimes longer if legal or a rebrand gets tangled into it.
That gap matters because the two paths often produce similar short-term conversion lifts. We've seen a £2,000 optimization sprint beat a £15,000 redesign on conversion rate within the first month, simply because the redesign spent its budget on visual polish while the sprint spent it on removing friction. Polish matters eventually. Friction matters immediately. If your budget forces a choice, friction wins every time.
Who Should Actually Make This Call
This decision gets made badly when it's made by the person who looks at the site the most, usually the founder or a senior marketer, because they're the most bored of the current design. Fair enough as a human reaction, but it's a bias worth naming out loud. The people who should weigh in are the ones closest to the data: whoever owns SEO and organic traffic, whoever runs paid campaigns and watches landing page conversion daily, and sales, who hear directly what confused a prospect on a call.
If those three groups agree the site is losing qualified people at a specific point, that's real evidence. If the only complaint is "I'm tired of looking at it," that's a preference, not a business case, and it shouldn't set the budget on its own.
A Note On Timing
There's one more variable worth naming honestly: sometimes the right answer is neither, at least not yet. If you're about to close a funding round, change your core offer, or enter a new market within the next two quarters, spending on a redesign now means redoing parts of it again in six months. In that case, run the cheap optimization fixes to stop the bleeding, and hold the full rebuild until the business itself has settled into whatever it's about to become. A redesign built around a positioning that's still shifting underneath it rarely survives contact with the next strategy meeting.
A Simple Decision Table
If your bounce rate is fine but conversion is weak, optimize the page, not the site. If the whole experience feels dated but functions, optimize first and see how far it gets you before spending on a rebuild. If the brand has moved on from what the site says, redesign. If the CMS is unmaintainable or unsafe to touch, redesign. If traffic is healthy and leads are thin, that's almost always an optimization problem wearing a redesign costume.
Most founders default to redesign because it feels like progress. Optimization feels like admitting the old work wasn't perfect. But the goal isn't a prettier site, it's more qualified conversations, and a £500 optimization sprint that lifts conversion 20% beats an £8,000 redesign that looks better and converts the same.
How To Test Which One You Actually Need
Before committing to either path, run a two-week test. Pick your highest-traffic page. Rewrite the hero, cut the form fields, tighten the CTA, and swap in one real testimonial with a name and result attached. Leave everything else alone.
If conversion moves meaningfully, you've just proven the site's bones are fine; you needed optimization, not a rebuild. If it barely budges, you've learned something more useful than any stakeholder meeting would tell you: the problem sits deeper than copy, and a redesign is worth the spend.
The Takeaway
- Diagnose before you brief anyone: pull bounce rate, time on page, and conversion rate first.
- Answer the five questions honestly; two or more "structural" answers means redesign.
- Optimization fixes underselling; redesign fixes confusion, brand mismatch, and broken infrastructure.
- Run a two-week test on your best page before committing to a full rebuild.
- If you redesign, plan redirects and tracking before launch, never once it's already live.
A tired site and a broken one look the same from a distance. Up close, they need completely different fixes, and completely different budgets. Twenty minutes with this framework tells you which one you're actually dealing with, before you spend the money finding out the hard way.
One last thing worth saying plainly: whichever path you choose, measure it the same way you'd measure any other spend in the business. If you commission an optimization sprint, set a target conversion lift before you start, so you're not tempted later to call any random movement a win. If you commission a redesign, agree in writing what happens to rankings and lead flow in the first thirty days, and who's accountable for the redirect map. Website work has a bad habit of being treated as a creative project instead of a revenue one. Treat it as revenue, and both the framework and the budget conversation get a lot easier to have.