Window Replacement Cost Calculator 2026

Window replacement costs depend mainly on glazing type: single-glazed approx. PLN 600/unit, double-glazed PLN 900/unit, triple-glazed PLN 1,300/unit. Add installation at approx. PLN 350/window. For 8 double-glazed windows with installation, total cost is about PLN 10,000.

Single-glazed windows have one air gap (Ug approx. 2.8 W/m²K). Double-glazed achieve Ug approx. 1.0 W/m²K and meet 2026 technical requirements. Triple-glazed with low-emission glass and argon filling reach Ug as low as 0.5 W/m²K — ideal for passive houses. For typical construction, double-glazed windows are recommended.

Professional window installation costs about PLN 200–500/unit (the calculator uses PLN 350). It includes: removing the old window, fitting the new one on anchors, sealing with foam, and applying a vapour-permeable membrane (three-layer installation per ITB standards). DIY installation is possible but poor installation eliminates thermal performance and creates thermal bridges.

When choosing windows check: Uw coefficient (whole window) — min. 0.9 W/m²K from 2026, Ug glass coefficient, burglary resistance class (at least RC2 for ground floor), acoustics (Rw ≥ 30 dB near busy roads), number of profile chambers (5–7), colour/laminate range. Choose a manufacturer certified by IFT or ift Rosenheim.

Replace windows when: they are over 20–25 years old (especially old wooden box-type), condensation appears between panes, profiles are warped or rotted, windows do not close tightly, you feel draughts with closed windows, coloured profiles have faded or cracked. Replacement can reduce heating costs by 15–25%.

In most cases, replacing windows in the same opening requires no formalities — it is a standard repair. Exceptions: changing the size of the window opening (requires notification or permit), listed buildings or conservation areas (conservator's approval required). Always check with your local authority.

Replacing old windows with modern double or triple-glazed units can reduce heat loss through windows by 30–50%. In a 150 m² house with 10 windows, savings can be PLN 800–1,500/year. With an investment of PLN 12,000–16,000, payback period is 10–20 years — but thermal and acoustic comfort improves immediately.

The Clean Air programme 2026 offers subsidies for window replacement as part of home insulation: up to 25% for basic level, up to 45% for enhanced level and up to 90% for the highest level (lower-income households). Applications are submitted via mojczystepowietrze.gov.pl or through regional WFOŚiGW offices. Replaced windows must meet Uw ≤ 0.9 W/m²K.

Installing one window takes an experienced team about 1–2 hours (including removing the old one). Replacing 8–10 windows usually takes 1–2 working days. After installation, interior finishing (plaster, window sills) takes 1–3 working days. Preparation: protect furniture from dust, ensure access to windows from inside.

PVC windows require minimal maintenance: clean profiles once a year with a damp cloth (avoid aggressive detergents), lubricate hinges and fittings with technical oil or a dedicated product, adjust fittings seasonally (summer/winter position), check seals and replace every 10–15 years. Well-maintained PVC windows last 30–40 years.