Working file M1.6

Triple glazing cost (UK 2026)

Triple glazing cost: published installed cost range with the source against each end, plus how it sits in the PAS 2035 fabric-first sequence.

Cost in 2026

Triple glazing cost (UK 2026). The published installed range in 2026 is Around £12,000 to £22,000 for a typical 9-window 3-bed (Passivhaus Trust v1.3 Jan 2026 and GGF publishers), or £1,300 to £2,400 per window for a high-spec timber-aluminium system. Both ends of that range are stated rather than collapsed to a midpoint, because the spread reflects real differences in scope, access and grant eligibility rather than installer mark-up.

What drives the spread

  • Frame: uPVC, aluminium-clad timber, full timber.
  • Glass: Ug 0.5 to 0.7 W/m²K target.
  • Listed and conservation-area constraints on frame profile.
  • Heritage timber sliding-sash 'slimlite' double is often the better answer than triple in protected stock.
Surveyed 1 October 2026. Ofgem cap for 1 October to 31 December 2026 applied (gas 7.97p, elec 26.32p, gas standing 29.68p, elec standing 54.83p). Next scheduled review 25 November 2026 (January cap announcement). [ref M1.6]
By Oliver Wakefield-Smith, Founder, Digital Signet. Corrections to oliver at digitalsignet dot com.