Smell triggers some of the most powerful emotional responses and can cause some of our most visceral responses.

The olfactory bulb is part of the limbic system, the emotional and memory centre of the brain, but in many ways, smell remains a mystery. Science has yet to pinpoint exactly how the brain processes and expresses smells, and much of what we do know was only very recently agreed upon.

Despite its mysteries, smell is pervasive as we constantly breathe, to the extent that we have to switch off from many of the smells our noses detect. Because of this, says Victoria Henshaw, author of Urban Smellscapes: Understanding and Designing City Smell Environments, “we frequently don’t appreciate the contribution smells make to everyday experiences of places and buildings.”

Traditionally in the area of architecture, smell has been something to design out of a building through means such as a ventilation system in a commercial kitchen or measures to ensure traffic pollution is minimised within the building. In the modern world, smell has mainly been factored into building design as something unpleasant that needs to be managed, a problematic element to be designed out.

This wasn’t always the case, with smells often deliberately incorporated into architecture, such as medieval garderobes designed so that the ammonia smells from latrine shafts would repel moths from stored robes. For a less eye-watering example, consider orangeries, with the smells of blossoms during the winter creating a space that was far more than a simple greenhouse.

Today, with a growing emphasis on designing buildings with all five senses in mind, there is a renewed focus on the power of smell and how it can positively contribute to our experience of a building.

The power of smell has been recognised by branding experts and many retailers now pump scents through their stores to encourage purchases and to elicit particular consumer behaviours. Supermarkets using the smell of freshly baked bread is a classic example of this marketing strategy.

This is now extending to other workplaces with certain scents, such as cinnamon, mint, lemon, orange and rosemary being shown to boost productivity. And it’s not just pleasant smells being used; Thorpe Park, a theme park in the United Kingdom, sprayed a pungent urine scent inside its Saw 4 attraction to heighten feelings of horror. Scent distribution systems are becoming increasingly sophisticated – beyond candles and oil burners – creating new opportunities for architects to deliberately consider orchestrating certain smells in building design.

Of course, the materials used for a building, its fittings and furnishings also contribute to smell. Timbers like oak, pine and cedar all issue their own unique scents, as do materials like terracotta, leather, and somewhat surprisingly, concrete.

As Jonathan Foyle says in his article Scent of a Building, “smell is intrinsic to the personality of a place.”

When used in combination with other sensory elements, smell can play a central role in creating a specific atmosphere within a building. The considered and creative use of smell can generate new opportunities to create buildings and spaces that delight and satisfy all of our senses.