The IGU is sourced from AGP (Architectural Glass Products), an APL sister company that operates New Zealand’s most advanced double-glazing plant near Cambridge.

The AGP system incorporates industry-leading ATS (Architectural Thermal Spacer) technology, as well as Argon gas and a 'Solux-E' low-E coating. These features, when combined in a single product, give the most effective thermal solution to heat retention in high-level glazing. Combined with the nylon thermal break included in all ThermalHEART aluminium profiles, the AGP glazing minimises condensation and gives the roof window an improved R-value. A market-leading 12-year warranty is offered on the glazing.

ThermalHEART window and door products are available from Altherm, First and Vantage manufacturers nationwide. The roof window offering can be dual coloured to match interior and exterior colour schemes and can be custom-made to required dimensions. Its structural glazed design means flush edges — no ponding of water allows windows to be installed to low roof pitches.

ThermalHEART roof windows can be fixed, or hinge-opening with control by manual winder, toggle switch to open and close electronically, or with remote touchpad with four open/close options. An auto rain-sensor feature can activate closing in electronically controlled products.