How many doors exist in the world?
As a passionate gamer, I‘m continually amazed by the vast scale of immersive virtual worlds constructed by talented development teams. But even the sprawling lands of epic adventures like Skyrim or The Witcher 3 pale in comparison to the mind-boggling number of real doors that can be found across our planet.
Through the Front Door – Residential Doors
Let‘s start our journey by entering the front door of residential homes. With around 2.4 billion households globally according to 2022 United Nations data, we already have an impressively high baseline. Research from the Builders Hardware Manufacturers Association suggests an average of around 7 exterior doors per single-family dwelling. For multi-family units the average is closer to 3. Taking worldwide variation into account, 5 doors per residence seems like a reasonable compromise. That equates to approximately 12 billion residential doors standing between us and our cozy abodes. For comparison, Minecraft has sold over 350 million copies as one of the best selling video games in history – our real-world residential door count has already left Minecraft‘s sales in the dust over 30 times over! We‘re just getting started here.
The Businesses Next Door – Commercial and Industrial Doors
Office buildings, factories, hospitals, schools – these structures need secured entry points allowing authorized access while preventing unauthorized entry. Medical centers like hospitals require numerous interior doors as well for privacy, containment, and workflow control between departments. Schools are similarly compartmentalized due to both practical and safety considerations. Hotels have doors to every private room of course. And the facilities and machinery of industrial facilities involve doors of all types and durability levels.
Approximately 209 billion square feet of commercial real estate building space existed globally as of 2021 according to Statista. Cushman & Wakefield finds industrial real estate availability in the Americas alone amounts to over 18 billion square feet. Modeling a cautious estimate of 10 doors per 10,000 square feet for commercial buildings and 5 doors per 10,000 square feet for industrial brings us to 214 billion additional doors and counting!
What‘s Behind Door Number… – Vehicles
While we gearheads love talking engines, mods, and performance benchmarks, one specification often overlooked is door count. Sedans feature 4 or more doors of course while most SUVs offer cargo access through a rear hatch or liftgate. The iconic gamer chariot, the 2023 VW Bus, has up to 7 doors across its passenger and cargo configurations. More conservatively, if we take the approximately 1.5 billion vehicles in use globally and estimate 85% as 4-door models, that nets us another 4.5 billion vehicle doors out on the roads and trails across the real world.
Secret Stashes – Furniture
Don‘t forget that our storage furniture offers additional doors and entry points that add up substantially when global shipments are considered. Armoires, dressers, cabinets, closets, pantries…not only our homes but also classrooms, offices, labs, maker spaces, workshops and more contain units segmented into compartments and access points. Roughly 550 million furniture shipments occur globally each year – estimating 60% of those include door-equipped storage, and 5 doors per unit yields 165 billion more thresholds to new possibilities!
In total from our residential, commercial, automotive, and furniture door tallies we‘ve uncovered about 396 billion doors that actually exist. But is that truly the upper limit of what our human civilization has architected?
Beyond All Limits – Speculative Estimates
Dedicated mathematicians have continued to push the estimation envelope on global door counts as an intriguing abstract problem to tackle. One published journal approach couples worldwide per capita appropriate building space figures with door density ratios adjusted for cultural variations. Their upper ceiling estimate adds another potential 200 billion doors into the mix! Architectural theorists argue certain reactive smart building materials and nano-machines may already constitute "doors" at microscopic scales in some sense too.
So in the end, while we may not have an undisputed Guinness Book world record figure, if you ask a passionate gamer I‘d confidently wager there are more mysteriously beckoning doors out there than any of us realize – doors to adventure, doors to fortune, and doors to the incredible future ahead! We may never open every single one – but imagining where they could all lead is exploration and discovery at its most exciting! Now if you‘ll excuse me, I feel compelled to reinstall Skyrim and wander its frozen northern lands yet again…I hear there‘s a hidden tavern door somewhere deep in the mountains that I somehow still haven‘t uncovered in over 200 hours of gameplay! Or perhaps I‘ll simply take a quiet walk outside to appreciate each doorway I pass by today in my own neighborhood with renewed awe.
