The verdict in three sentences
If technical debt is manageable and the structure still sound, a partial redesign at EUR 12,000-25,000 over 6 weeks is enough. If the Core Web Vitals score drops below 50, the CMS is unmaintained and conversion stalls, a full rebuild at EUR 30,000-60,000 over 14 weeks is required. The right method is not intuition: it is a weighted scoring that decides objectively.
Redesign or rebuild: the 2026 comparison
| Criterion | Partial redesign | Full rebuild |
|---|---|---|
| 2026 cost | EUR 12,000-25,000 | EUR 30,000-60,000 |
| Timeline | 6-8 weeks | 12-16 weeks |
| SEO risk | Low | Moderate (redirects) |
| Performance gain | +20-40% | +60-120% |
| Post-project lifespan | 2-3 years | 5-7 years |
| Team disruption | Low | High |
A redesign keeps the technical base and refreshes design, content and journeys. A rebuild starts from a new architecture, costlier but durable.
The decision matrix: 10 weighted criteria
Score each criterion 0 (favours redesign) to 3 (favours rebuild), multiply by the weight, sum. Total out of 60.
| Criterion | Weight | Rebuild signal |
|---|---|---|
| Technical debt | 3 | Unmaintained code, obsolete dependencies |
| Core Web Vitals | 3 | Score < 50 on mobile |
| Supported CMS | 2 | End-of-life version |
| Conversion rate | 2 | Declining for 12 months |
| Security | 2 | Unfixable vulnerabilities |
| Scalability | 2 | Cannot add features |
| Design consistency | 1 | Obsolete brand guidelines |
| Mobile | 2 | Not responsive |
| Technical SEO | 2 | URL structure to redo |
| Maintenance cost | 1 | Rising every year |
Score below 25: redesign. Between 25 and 40: heavy redesign or rebuild by budget. Above 40: rebuild.
Mini case study
Sophie, marketing director of a B2B software vendor, runs a 6-year-old site. She scores: technical debt 3x3=9, CWV 3x3=9, CMS 2x3=6, conversion 2x2=4, security 2x2=4, scalability 2x3=6, design 1x1=1, mobile 2x2=4, SEO 2x2=4, maintenance 1x2=2. Total: 49/60. The verdict is clear: rebuild. She budgets EUR 42,000, projects +80% performance and conversion rising from 1.8% to 3.1%, an estimated payback in 9 months.
FAQ
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Can a redesign destroy my SEO?
A partial redesign preserves URLs and content, so risk is low. A rebuild demands a rigorous 301 redirect plan to avoid a traffic drop.
How long to keep a site before a redesign?
In 2026, a B2B site is refreshed every 2-3 years and rebuilt every 5-7. Beyond that, technical debt costs more than the rebuild.
Is a rebuild always worth the premium?
Only if the score exceeds 40. Below that, you pay for novelty without a proportional gain in performance or conversion.
Can you rebuild in stages?
Yes, a progressive approach (page by page or section by section) spreads the budget over 2-3 quarters and limits operational disruption.
What conversion gain to expect?
A well-run rebuild on an ageing site typically lifts conversion 40-90%, depending on the starting performance gap.
Let's scope your project. Send us your current URL and goals: we will run your 10-criteria scoring for free and tell you redesign or rebuild, with an indicative budget. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
