We design buildings for the eyes. Increasingly, we design them for the ears too: acoustic panels, soundscaping, the careful hum of a well-run lobby. The nose comes last, if it comes at all. And when we do think about how a place smells, we are usually thinking about how to make it smell like nothing.
Of all the senses, smell is the one our built environments are engineered to suppress.
The deodorized ideal
The historian Alain Corbin traced how Western cities spent the eighteenth and nineteenth centuries at war with their own smells. At first, because odor was believed to carry disease (the miasma theory), and later because an absence of smell became a marker of hygiene, respectability, and class. To smell of something was to be suspect, to smell of nothing was to be modern.
We inherited that ideal and built it into our infrastructure. Ventilation standards, air handling, the whole apparatus of modern climate control quietly encode a goal: neutral air. The "new building smell" we notice is mostly the off-gassing of materials we haven't yet managed to silence. I personally love that smell though.
So when someone asks what it would mean to design with smell, the first honest answer is that we already design against it, constantly, and rarely notice we've made a choice.
The oversold promise
Into that vacuum walks scent marketing, promising the opposite: pump in the right smell and watch people linger, feel good, and spend that money.
The famous number here comes from a 1995 study in a Las Vegas casino, where one odorized area saw slot-machine gambling rise about 45% over a single weekend. It gets quoted everywhere. What gets quoted less is that the study ran for one weekend, in one casino, was never replicated. And that of the two scents tested, only one did anything at all.
That last detail turns out to be the pattern. When researchers pooled the better studies into a proper meta-analysis, they found that a pleasant ambient scent does have a real effect on how people feel and behave in a space, albeit a modest one, and a deeply conditional one. What matters is whether the smell fits, like a smell of pine tree during Christmas season. The congruence between the smell, the place, the product, even the music playing matters. The eye-popping figures in sensory-branding decks are mostly built on the weakest studies.
So: scent can shape experience but it is not a lever you pull for guaranteed sales, and treating it as one is where most "designing with smell" goes wrong.
What's actually worth taking seriously
All this means the interesting version is about something other than manipulation.
Every space already has a smell: the bakery, the hospital corridor, the subway platform, the particular pine of a particular trail. Geographers gave this a name in the 1980s: the smellscape, the olfactory counterpart to a landscape. More recently, people have started asking how cities and buildings might be designed with it in mind rather than only against it. Smell is bound up with our sense of place, and our memory of it, in a way sight isn't; a smellscape is part of what makes somewhere feel like somewhere.
Taking that seriously is mostly a matter of attention. What does this place actually smell like? Which of those smells are part of its character, and which are just neglect? What does the ventilation flatten that might have been worth keeping and what does it remove much to everyone's delight? These are design questions, and almost nobody asks them.
The biggest caveat
You can close your eyes. You can put in earplugs. You cannot stop breathing the air you're in.
Smell is the sense you can't opt out of, and that makes adding it to a shared space an ethical act, not just an aesthetic one. In population surveys, roughly a third of people report adverse health effects from fragranced products. For someone with asthma, migraine, or chemical sensitivity, a lobby with a "signature scent" isn't an experience. It's a space they have to tolerate or leave.
Two more practical truths make deliberate scenting harder than it looks. Your nose adapts within minutes, so whoever installs the scent stops smelling it and turns it up, which is a massacre for the sensitive person walking in fresh. And what smells "good" is heavily learned and cultural, not universal, so there is no scent that reads as pleasant to everyone (unless it is vanilla).
Put together, this means the most common vision of "designing with smell", piping a branded fragrance through the vents, is often the least defensible one.
So what would it actually mean?
I think designing with smell, done honestly, looks less like adding and more like listening.
It means treating the existing smellscape as real: noticing it, protecting the smells that give a place its character, and mostly subtracting. Removing what's genuinely bad rather than masking it with something worse. Where scent is added, it means doing so with restraint, at low concentrations, with real ways to avoid it, and with the people who can't tolerate it treated as the design constraint rather than an afterthought. It means asking what a space should smell like the way we already ask what it should sound like, and being willing to answer, sometimes, "like clean air, and like the thing it actually is."
That's a quieter ambition than the one the fragrance industry sells. But it's the one that survives contact with a real building, and real people breathing in it.
