Green Buildings — Scientific Principles

Scientific Principles

Follow the building life cycle

Operational energy supports services such as cooling and lighting. Embodied impacts concern materials and other stages under a defined assessment boundary. Embodied energy and embodied carbon use different units and are not interchangeable. UNEP's September 2023 materials report provides a dated reference for the wider life-cycle approach.

Reduce demand and deliver the service

Shading and envelope design can reduce demand; efficient equipment reduces input for a service; renewable generation changes supply. Daylight can reduce artificial lighting while also affecting heat gain and glare. Climate, orientation, occupancy and operating conditions determine the useful combination.

Calculate comparable metrics

A building using 100,000 kilowatt-hours over a year across one thousand square metres has an intensity of one hundred kilowatt-hours per square metre. At eighty thousand, the intensity is eighty and the reduction is twenty percent under comparable conditions. A hypothetical retrofit adding twenty emission units and saving five annually has a simple four-year carbon payback if the assumptions persist.

Keep boundaries and requirements explicit

Annual net energy can balance despite hourly grid imports. It does not establish zero embodied emissions or water use. BEE's 2024 commercial code and residential Eco-Niwas Samhita are relevant references, but publication, legal implementation and voluntary rating are distinct. Actual performance needs measurement and suitable operation rather than an unconditional inference from a certificate.