The verdict in three sentences
A partial redesign (4,000-9,000 EUR net) is the right call when the technical foundation is sound and the goal is aesthetic. A rebuild (12,000-25,000 EUR net) becomes necessary as soon as technical debt drags down performance, security or scalability. The tipping point reads on three numbers: technical health score, migration cost and four-year TCO.
The quantified decision matrix
Before deciding, score the existing site on objective criteria. Here is the 2026 grid that separates redesign from rebuild.
| Criterion | Partial redesign | Rebuild |
|---|---|---|
| 2026 budget (EUR net) | 4,000 - 9,000 | 12,000 - 25,000 |
| Average timeline | 6 weeks | 12 weeks |
| Target Core Web Vitals | 60 - 80 | > 90 |
| Technical debt | Retained | Eliminated |
| SEO risk at migration | Low | Moderate (redirects) |
| 4-year TCO | Baseline | -30% |
| Scalability (new features) | Limited | High |
The technical health score guides the choice. Add the points below: above a threshold, rebuilding becomes more profitable.
| Health signal | Weight | Interpretation |
|---|---|---|
| Lighthouse score < 50 | 3 | Rebuild recommended |
| Unmaintained CMS/plugins | 2 | Security risk |
| Design > 5 years | 1 | Redesign often enough |
| Declining organic traffic | 2 | SEO redesign priority |
| Need for new features | 3 | Rebuild suited |
| Known security flaws | 3 | Rebuild urgent |
Beyond 8 cumulative points, rebuilding is generally the better four-year economic choice, despite a higher entry ticket.
The financial tipping point
The decisive calculation compares the four-year TCO. A legacy WordPress site redesigned at 6,000 EUR but maintained at 200 EUR/month with repeated fixes can exceed 15,600 EUR over four years. A Next.js rebuild at 18,000 EUR, with maintenance cut to 120 EUR/month, comes to 23,760 EUR but with better performance and zero debt. If the redesign must be redone in two years, the rebuild is immediately more profitable.
Mini case study
Thomas, director of a 35-person B2B services SME in Manchester, is torn over a 7-year-old WordPress site (Lighthouse 42, 3 unmaintained plugins, traffic down 18%). His health score reaches 10 points. He chooses a Next.js rebuild at 17,000 EUR (net). Within six months, Core Web Vitals rise from 42 to 94, organic traffic recovers 22% and bounce rate drops 11 points. The 11,000 EUR premium over a redesign is repaid by the lead increase from the eighth month.
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FAQ
How do I know if my site has technical debt?
An audit measures the Lighthouse score, dependency health, security and code structure. A score under 50 and unmaintained plugins are strong signals in favour of a rebuild.
Does rebuilding lose my search rankings?
SEO risk is moderate and manageable with a rigorous 301 redirect plan and preservation of key URLs. Done well, a rebuild improves SEO through better performance.
What is the real gain of a Next.js site?
Performance (Core Web Vitals > 90), security, scalability and a TCO roughly 30% lower over four years thanks to lighter maintenance. It is a structural choice for a growing company.
How long between redesign and rebuild?
Expect about 6 weeks for a partial redesign versus 12 weeks for a full rebuild in 2026, depending on the volume of content to migrate.
When is a simple redesign genuinely enough?
When the technical foundation is sound, security up to date and the goal purely aesthetic or editorial. In that case, 4,000 to 9,000 EUR is enough without starting over.
Let's scope your project. Send us your current site URL: we produce a technical health score and recommend redesign (~6,000 EUR) or rebuild (~18,000 EUR) with a quantified TCO. 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.
