Residential Series ThermalHEART® windows and doors are a mainstream product range that comply with NZBC clause H1 Energy Efficiency (all climate zones) when used in conjunction with high performing Low-E double glazing. They include thermal breaks for maximum performance — glass fibre-reinforced polyamide inserts. Products include fixed, awning and casement windows, sliding, stacking and bi-folding windows and doors, and hinged and French doors.