Reducing operational energy demand is a fundamental part of lower-carbon building design. While LED technology has made electric lighting more efficient, an equally important strategy is to reduce the need for artificial lighting in the first place by making better use of available daylight.

Tubular daylighting devices (TDDs) extend daylight beyond the areas typically reached by windows or conventional roof glazing. Solatube Daylighting Systems capture daylight at roof level, transfer it through highly reflective tubing and distribute it into interior spaces. This makes the technology particularly relevant for corridors, amenities, deep-plan areas and other spaces with limited access to external glazing.

Effective daylighting is not simply about introducing more sunlight. Useful light delivery and thermal performance need to work together. Solatube Spectralight Infinity tubing provides specular reflectance greater than 99%, with wavelength-specific reflectance of up to 99.7% in the visible spectrum, supporting efficient daylight transfer through the system. INFRAREDuction Technology filters infrared wavelengths to minimise unwanted solar heat gain.

The Cadbury National Distribution Centre in Māngere demonstrates how daylighting can work alongside electric lighting controls in practice. The warehouse incorporated 72 Solatube 750DS-OC Daylighting Systems integrated with the Building Management System, allowing electric lighting to be reduced when sufficient daylight was available. The site manager reported electric lighting operating at 66% in the picking area and 33% in storage areas, showing how daylight and lighting controls can work together to reduce daytime reliance on electric lighting.

In New Zealand, Solatube Daylight Systems are supplied by Just Life Group Limited and are covered by BRANZ Appraisal 665 [2024]. The appraisal confirms that, when specified and installed in accordance with its requirements, the systems contribute to compliance with NZBC G7 Natural Light and H1 Energy Efficiency.

For architects designing for lower operational energy demand, daylighting should be considered alongside electric lighting from the earliest stages of design. Bringing useful daylight deeper into a building can reduce dependence on artificial lighting during daylight hours while supporting a considered approach to energy efficiency.