Green Buildings — Prelims Strategy

Prelims Strategy

Check whether the question concerns energy, emissions, water or another resource. Operational energy and embodied carbon are different quantities; kilowatt-hours cannot be compared directly with kilograms of carbon-dioxide equivalent. A life-cycle claim also requires a stated boundary and period.

For energy-use intensity, divide the specified annual energy by the specified area. One hundred thousand kilowatt-hours over one thousand square metres gives one hundred kilowatt-hours per square metre. A fall to eighty thousand is a twenty-percent reduction under comparable conditions. For simple carbon payback, divide added embodied emissions by annual avoided emissions, giving four years for twenty divided by five.

Watch net-zero wording. Annual energy balance can coexist with hourly grid imports and does not establish zero material emissions or water demand. More glazing does not automatically lower total energy because daylight, heat gains and glare interact. Finally, distinguish a national code, applicable legal implementation and voluntary rating. Their shared environmental purpose does not make their scope or legal effect identical.