Facade insulation: polystyrene or mineral wool? 2026 prices and payback

An uninsulated house from the 1970s–90s loses up to a third of its heat through the walls. Quality contact insulation (ETICS) is therefore one of the fastest-payback investments — heating bills typically drop 30–50% and the house gets a brand-new facade.

Polystyrene (EPS) — the most common choice

• Price: from about CZK 1,800/m² including labour, adhesives, mesh and render.
• Pros: best price/performance ratio, low weight, easy to work with.
• Cons: lower vapour permeability, weaker acoustics, fire-safety limits on taller buildings.

Mineral wool — the premium solution

• Price: from about CZK 2,200/m² including labour.
• Pros: vapour-open (the house "breathes"), excellent sound insulation, non-combustible.
• Cons: higher price, more weight, demands precise installation.

When is new render alone enough?

If the house is already insulated or has thick walls with good parameters, a repair plus new thin-layer render may suffice — from about CZK 1,300/m². The facade gets a fresh look for a fraction of the insulation cost. We determine the right option during an on-site inspection.

How insulation proceeds

1. Inspection and design: we assess the substrate, moisture and thermal bridges and propose insulant thickness (commonly 14–20 cm today).
2. Scaffolding and preparation: cleaning, priming, removing sills and downpipes.
3. Gluing and anchoring the insulant, sanding, corner and expansion profiles.
4. Reinforcement layer: base coat with mesh — the key crack-prevention layer.
5. Primer and final render (silicone, grain size of your choice), new sills and details.

A family house typically takes us 3–5 weeks including scaffolding.

Return on investment

At today's energy prices, insulating an average house (150–200 m² of facade) pays back in roughly 7–12 years on heat savings alone — not counting higher property value and better summer comfort. With a subsidy, payback is even faster.

You can calculate your facade area and an indicative price in our online calculator — choose "Facade / insulation", enter the square metres and see the budget instantly.