The verdict in three sentences
A low-carbon website aligned with eco-design standards costs EUR 8,000 to 14,000 in Amsterdam in 2026, or 10 to 20% more than a conventional site of the same scope. The premium buys pages under 500 KB, an EcoIndex score of A or B and 40 to 60% faster mobile loading, which also improves conversion and SEO. For a B Corp, it is above all verifiable proof that its digital tools match its sustainability claims.
What a EUR 8,000 to 14,000 budget covers
The RGESN (the French general framework for eco-designing digital services), updated in 2024, lists 78 criteria across 9 families and is one of the most detailed references in Europe, alongside the W3C Web Sustainability Guidelines. The sustainability lead of an Amsterdam SME does not need to tick them all, but should be able to publish a credible eco-design statement.
| Item | Low budget | High budget | Eco-design specifics |
|---|---|---|---|
| Scoping and initial eco-design audit | EUR 1,000 | EUR 1,800 | Applicable criteria, quantified targets |
| Sober design | EUR 1,800 | EUR 3,000 | System fonts, light palettes, minimal video |
| Lightweight development | EUR 3,000 | EUR 5,500 | Static site or lean CMS, no unnecessary scripts |
| Media optimisation | EUR 600 | EUR 1,200 | AVIF and WebP images, lazy loading, weight caps |
| Green hosting and configuration | EUR 400 | EUR 800 | EU datacentre running on renewable energy |
| EcoIndex measurement and eco-design statement | EUR 700 | EUR 1,000 | Page-by-page report, published statement |
| Editor training | EUR 500 | EUR 700 | Weight rules for images and documents |
| Total | EUR 8,000 | EUR 14,000 | 7 to 10 weeks |
Maintenance runs around EUR 100 per month, including green hosting, backups and a quarterly page-weight check.
Conventional site versus low-carbon site: measurable gaps
| Indicator | Conventional corporate site 2026 | Eco-designed site |
|---|---|---|
| Average page weight | 2.5 to 4 MB | 300 to 500 KB |
| HTTP requests per page | 80 to 150 | 15 to 35 |
| EcoIndex score | D to F | A or B |
| Mobile display time on average 4G | 3.5 to 5 s | 1.2 to 2 s |
| Estimated emissions for 10,000 views a month | 25 to 40 kg CO2e per year | 4 to 8 kg CO2e per year |
| Target technical lifespan | 3 to 4 years | 5 to 7 years |
| Monthly maintenance cost | EUR 120 to 250 | EUR 80 to 120 |
The site's direct environmental gain remains modest at company scale. The benefit lies elsewhere: consistency with a demanding certification, better accessibility on older devices and speed that lifts conversion, often by 10 to 20% when load time is halved.
The trade-offs that keep pages under 500 KB
First trade-off: the home page video. A 15-second background video alone weighs 3 to 8 MB. Replacing it with a well-compressed 80 KB photo moves the home page from E to A.
Second trade-off: third-party tools. Every ad tracker, chat widget or external font adds 50 to 400 KB. Lightweight cookieless analytics is enough to run a B2B site.
Third trade-off: PDFs. A 25 MB impact report downloaded 500 times a year means 12.5 GB transferred. An HTML web version plus a 3 MB light PDF cuts that volume eightfold.
Mini case study
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Sanne, sustainability lead at a 45-person B Corp SME in Amsterdam, replaces a site weighing 3.2 MB per page (EcoIndex E) with an eco-designed site for EUR 11,500. Average weight drops to 420 KB, the score reaches A on 80% of pages and mobile display time falls by 55%. With 2,400 visits a month and a contact rate rising from 1.5% to 1.8%, the company gains about 7 more qualified requests a month. At a 20% close rate and an average margin of EUR 3,000 per contract, that is about EUR 4,200 of monthly margin, enough to pay back the project in under three months.
FAQ
Is eco-design compliance mandatory for a private company?
No, the RGESN is gradually becoming binding for public bodies and large digital services in France. For an SME it is voluntary, but publishing a statement against 78 criteria strengthens a B Corp file or an EcoVadis rating.
Is a low-carbon site less attractive?
No, it is more restrained. The design relies on typography, white space and a few highly optimised images, and most visitors mainly notice that it loads in under 2 seconds.
How do we check the EcoIndex score?
The free online EcoIndex tool grades each page from A to G. We deliver a report on the 20 to 30 main pages and a quarterly check included in maintenance.
Which host should we choose?
A European host whose datacentres run on renewable energy and that publishes its PUE, ideally below 1.3. Cost remains comparable, EUR 10 to 40 per month.
Can we eco-design an existing site without a redesign?
Yes, an audit and targeted optimisations cost EUR 2,500 to 5,000 and often cut page weight by 50%. Beyond that, a redesign becomes more cost-effective.
Let's scope your project. Send us your current site address and your sustainability commitments for a free EcoIndex audit and a quote between EUR 8,000 and 14,000. 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.
