The Vacuum Glazed Traditional Box Sash window is designed to serve as an high thermal performance sash window for heritage projects and buildings located in conservation areas. Its vacuum glazing is 8.3 mm thick, closely resembling single glazing while offering modern insulation.

This window is internally beaded for an enhanced security, with applied slim glazing bars, to keep the aesthetics of the original window but with a much greater performance, typically achieving a whole window U values of 1.1–1.2 W/m²·K and acoustic ratings of 38–30 dB.

Constructed with slim frame and sash profiles, the vacuum glazed traditional box sash window functions with a classic system of cords, weights, and pulleys, a spring balance option is also available. These windows are typically installed within a check reveal, allowing the box to remain largely concealed behind external brick or stonework, although it can also be fitted flush with the brick face, where the box remains visible and is often finished with an architrave.

The vacuum glazed traditional box sash can be supplied fully finished with a three-coat spray applied microporous water-based paint system or can be supplied primed only for a topcoat to be applied on site by others.

All our windows come with a choice of sash lifts, fasteners, locks and pulley wheels with a wide range of option finishes including antique brass sash, polished chrome, satin nickel, polished brass, matt bronze and polished nickel.

Features and benefits:

Sash window.
1.1–1.2 W/m²·K U-values.
Water-based, stained or primed frame finish.
76% visible light transmittance.
Various cill sizes available from 35–110 mm.

Guarantees:

TRC Contracts Ltd offers robust guarantees on all TRC window ranges we supply and install. The following general terms apply on all new windows:

Expected Lifespan: All our windows are designed with a 60-year service life guarantee.
Manufacturing and Material Defects: 10-year guarantee.
Finishes: The standard three-coat opaque finished joinery is guaranteed for 10 years, and the stain finishes are guaranteed against blistering or flaking for six years.
Seals: The seals on double-glazed units are guaranteed for 10 years (from the date of delivery).
Ironmongery: Functional failure is guaranteed on ironmongery for two years.

Thermal performance Vacuum Glazed Traditional Box Sash windows