Performance Optimization & CRO for Chimney Services
STS Benelux, a chimney maintenance and inspection company serving Belgium and the Netherlands, needed their Next.js website optimized for speed and conversions. We delivered a comprehensive page speed optimization that cut LCP by 4 seconds, plus a full CRO overhaul that transformed weak CTAs and missing social proof into a conversion-focused experience.
STS Benelux had a functional Next.js website, but it was underperforming on both speed and conversions. Mobile performance scored just 69, LCP was a sluggish 7.1 seconds, and the site lacked social proof, urgency signals, and effective calls-to-action. We conducted a full technical audit and implemented a multi-phase optimization strategy across both performance and conversion rate optimization.
Page Speed Optimization
Over three optimization sessions, we transformed the site's Core Web Vitals: LCP dropped from 7.1s to 3.1s (-4.0s), Total Blocking Time fell from 280ms to just 23ms (-257ms), and Time to Interactive improved from 7.8s to 3.1s (-4.7s). Key techniques included converting hero images to WebP, fixing oversized image dimensions, replacing JavaScript-heavy components with CSS-only alternatives, lazy-loading below-the-fold components with next/dynamic, and optimizing package imports for tree-shaking. Accessibility reached a perfect 100, as did Best Practices and SEO scores.
The combination of page speed optimization and conversion rate optimization delivered measurable results — a faster, more persuasive website that turns visitors into qualified leads for STS Benelux.
Christian de Gruijter
CMO
Conversion Rate Optimization
We audited the site against 10 CRO benchmarks and implemented 20+ quick wins across all pages. Weak generic CTAs like "Meer Informatie" were replaced with action-oriented buttons tailored per service. A social proof bar (4.9/5 — 600+ satisfied customers) was added below the hero. Form titles were rewritten from instructions to value propositions, response time guarantees were placed near submit buttons, and urgency micro-copy was added near pricing sections.
Full-Page CRO Overhaul
Beyond the homepage, we optimized service detail pages with benefit-focused headlines and trust signals, fixed a dead CTA on the About page that linked to itself, added dark CTA sections at the end of key pages, and shortened pricing page CTAs for clarity. Every change was grounded in marketing psychology principles — from loss aversion in urgency copy to social proof placement near decision points. The result is a cohesive, conversion-focused experience across every page of the site.
