Edible or inhabited, energy consumption plays an important aspect in our lives. What if we start scrutinising our built calories and develop healthy construction habits, in the same way we count the calories and nutrients of our daily meals?

Everything we do relies on the energy that comes in the form of Calories, commonly expressed in Joules and Kilowatts Hour.

1 Kilocalorie = 4,184 Kilojoules = 0.00116222 KWh

A calorie measures the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. Calories in food provide energy in the form of heat so that our bodies can function. Our bodies store and "burn" calories as fuel. Many people who are trying to reach or maintain a healthy weight will count calories and try to reduce the caloric intake.

We all need energy to live and stay healthy, the question is how much of the energy we take in is in excess?

Health industry estimates we need a range from 1,600 to 2,400 calories per day for adult women and 2,000 to 3,000 calories per day for adult men; the low end of the range being recommended to sedentary individuals and the high end for active individuals.

Similarly, our hungry dwellings also need a lot of calories to keep us warm or cool in the cold or hot season and maintain the appropriate ventilation levels across the whole year. The energy bills, reveal the exact number of calories our buildings require to operate. These consumption rates are expressed in Kilo Joules or KWh.

The calories (energy) input for a conventional household of 4, is obviously significantly higher when compared with the daily calories for a typical adult. The comparison becomes relevant when we consider the cost escalation of the (limited) energy available to feed our dwellings, increasingly affecting our pockets, with the latter being only an immediate recoil. A slower reactive climate change pattern impacted by the audaciously use of natural resources, isn't too far either.

In a study by CSIRO - Typical House Energy Use - it was determined that the daily energy consumption for a conventional dwelling in Victoria (Australia) is ~ 41.3KWh.

~ 148 Giga calories per day ~ 41.3KWh per day ~ 15,075KWh per year

Passivhaus concept, in architecture and construction, has dedicated its attention into finding ways to reduce the financial burden of hungry and low efficient buildings, as well as achieving healthier lives in comfortable environments. A passivhaus dwelling uses up to 90% less energy to operate when compared with a standard dwelling of the same size:

~ 14.8 Giga calories per day ~ 4.13KWh per day ~ 1,507.5KWh per year

In conclusion, the energy used by a conventional dwelling can power up to 10 passivhaus buildings of the same size. This enables an answer to our above-mentioned question. 90% of the energy a conventional house uses, is in excess when compared with a passivhaus dwelling.

The key focus to achieve this significant energy reduction is paying attention to the external Building Fabric. This highly resilient coat needs to be Continuously Insulated without any Weak Gaps, be Airtight, allow Controlled Solar Gains and Ventilation and achieve the right Weather Protection levels.

Counting calories is healthy and sustainable! From the food we digest, the buildings we inhabit, to the vehicles we drive, the clothes we wear, the household items we all need, to electronics & equipment, everything requires access to calories in one form or another.