We have been very strong on energy efficiency in our houses for many years, and have full knowledge and experience with 'Net-Zero' construction and systems. Our basic standard comprises insulation 70% higher than code, under slab insulation in the basement, radiant floor heat, triple glazed fibreglass windows, natural ventilation, air-tight construction and heat recovery ventilators, low-wattage lighting, and passive solar heating with heat sinks and summer shading devices. This level of integrity in the building envelope - the exterior shell of your home - provides a very low energy loss level, an excellent starting point for adding technologies such as solar panels and air to air heat pumps to reach net zero CO2 levels.