The verdict in three sentences
A redesign (new design on an existing foundation) costs 30 to 50 % less than a rebuild (full stack reconstruction) and makes sense when the code is healthy but the look is dated. A rebuild becomes unavoidable once technical debt, an obsolete CMS or irrecoverable performance blocks any evolution. A rebuild's ROI lands in 12 to 24 months if conversion rises by 15 to 30 %.
The 2026 decision matrix
The right call depends on the state of the foundation, not the site's stated age. Here are the criteria that tip toward redesign or rebuild.
| Criterion | Leans to redesign | Leans to rebuild |
|---|---|---|
| Code age | < 4 years | > 5 years |
| CMS | maintained, current | obsolete, unsupported |
| Technical debt | low | high, blocking |
| Performance (LCP) | 2.5-4 s, recoverable | > 4 s, irrecoverable |
| Stack change | not planned | migration required |
| Indicative 2026 cost | 5,000 - 15,000 EUR | 15,000 - 45,000 EUR |
If three or more criteria lean to rebuild, a redesign is a band-aid: you would repay the reconstruction within 2-3 years. Better to invest once.
The ROI calc that decides
The financial call rests on expected conversion gain, not cost alone. Here are the 2026 orders of magnitude for a lead-generating B2B site.
| Scenario | Investment | Conversion gain | ROI reached |
|---|---|---|---|
| Light redesign | 8,000 EUR | +8-12 % | 6-10 months |
| Full redesign | 14,000 EUR | +15-20 % | 10-14 months |
| Standard rebuild | 28,000 EUR | +20-30 % | 12-18 months |
| Rebuild + migration | 42,000 EUR | +25-35 % | 18-24 months |
A rebuild costs two to three times more, but unlocks conversion and speed gains a cosmetic redesign cannot reach. The question is not "how much does it cost" but "how much does it return over 24 months".
Mini case study
Julien is CFO of a technical-services SME in Nantes. His site is 6 years old, on an unmaintained CMS, with a 5.2 s LCP. He hesitates between a redesign at 13,000 EUR and a rebuild at 30,000 EUR.
The matrix decides: obsolete CMS, high technical debt, irrecoverable LCP, three criteria for rebuild. ROI calc: the site generates 120 leads/year at 25 % close and a 6,000 EUR order, i.e. 180,000 EUR revenue. A rebuild targeting +25 % conversion adds 30 leads/year, i.e. 45,000 EUR added revenue. The 30,000 EUR rebuild pays back in 8 months of gain; the cosmetic redesign would only have postponed the problem. Julien chooses the rebuild.
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FAQ
What is the difference between a redesign and a rebuild?
A redesign keeps the technical foundation and renews design and content. A rebuild reconstructs the whole stack (CMS, code, hosting). A redesign costs 30-50 % less but does not fix deep technical debt.
At what age should I remake my site?
Age alone is not a criterion: a well-maintained 6-year-old site can hold. Look at the CMS, technical debt and performance. Beyond 5 years on an obsolete foundation, a rebuild often becomes the better option.
Is a rebuild profitable?
Yes if conversion rises 15-30 %. ROI is generally reached in 12-24 months. Do the maths: lead gain x close rate x average order, compared with the rebuild premium over a redesign.
Can SEO be migrated without loss during a rebuild?
Yes, with a rigorous 301 redirect plan and preserved URL structure. A poorly migrated rebuild can lose 30-40 % of traffic; a well-run one preserves, even improves, rankings.
How much does a full rebuild cost in 2026?
Between 15,000 and 45,000 EUR depending on scope and required migration. A rebuild with a stack change and data migration sits at the top of the range, where a redesign stays between 5,000 and 15,000 EUR.
Let's scope your project. Give us your site's age, current CMS and conversion goals, and we will tell you whether to redesign or rebuild. 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.
