A new study released by Melbourne-based premium LED company Brightgreen reveals how a home’s energy efficiency is being impacted by recessed lighting cut-outs and insulation gaps in the ceiling.

Modelled on government and academic research, Brightgreen’s study explains how choosing surface mounted LEDs instead of recessed fittings can help homeowners achieve substantial energy savings in temperature control, equivalent to the cost of lighting up an average-sized Australian home.

Surface-mounted LEDs eliminate air leakages and gaps in insulation, and require only half the total energy used by recessed equivalents after factoring in the extra load from ceiling cut-outs and gaps in insulation.

An average Australian home consumes 40 per cent of energy on heating and cooling alone. By combating air leakage and maximising insulation R-values, the energy ratings of a home can be boosted.

Warm air is more buoyant than cool air and will inevitably float upwards; having an airtight and well insulated ceiling is, therefore, particularly important during the cooler months. Similarly, the right choice of lights will reduce energy consumption by lighting and temperature control systems, contributing to overall home efficiency.

The Brightgreen study draws attention to the extra load placed on temperature control systems by recessed LEDs, encouraging all stakeholders from sustainable architects and builders to homeowners to embrace a whole new way of thinking about LED efficiency.

The study outlines the following three factors as primary considerations when assessing the overall efficiency of a luminaire:

Air leakage

Energy losses from air leakage are caused by conditioned air leaving the home through cracks and openings. Standard recessed downlights require cut-outs in the ceiling, preventing homeowners from having a totally sealed ceiling. Air leakage caused by recessed lighting cut-outs contributes to approximately 197.58 kWh per year of excess heating and cooling energy for an average-sized Australian home.


Home thermal efficiency relies on a well-insulated ceiling, which is not possible with recessed downlights since they require a safe clearance around each installation to prevent fire hazards. This clearance reduces insulation R-values by up to 0.5, resulting in increased heat conduction. In an average-sized Australian home, this amounts to approximately 194 kWh of additional temperature control energy usage per year.

Energy usage

Two key factors that determine the sustainability of any lighting product are energy usage and product lifetime. LEDs offer the assurance of exceptionally long product lifetimes and generally emit a higher amount of lumens per watt than other light sources.