Clarence Rimbro and his family live on an alternate earth, like many other people. The entire planet hosts a single house, protected by a huge forcefield. Said field is large enough to contain a five-acre greenhouse, which provides self-sufficient plants and animals for the family to eat. Even the air and water are self-sufficient. They have to be, because the earth he lives on has no life, and a carbon dioxide atmosphere. But there's a banging going on outside the forcefield, which means someone else is on his planet.
So the Housing Bureau sends two people to investigate, and they discover that Nazi Earth has also created an Interdimensional Travel Device, and were building homes not far from the Rimbro home. They're able to negotiate reasonably, since there's an infinite number of alternate earths to choose from. They leave, and Rimbro is told it was a geological problem, one that they fixed.
Once that's settled, Alec Mishnoff, who handled the negotiations with German Earth, is getting debriefed by his local Bureau Head, Berg. Berg questions Alec on why he was expecting to find a colony from another earth on that planet. It turns out, Alec wasn't expecting humans at all. Given the infinite vastness of space, Alec is expecting that they'll encounter aliens that have mastered Casual Interstellar Travel and want to colonize the planet, too. Berg is telling him how ridiculous the idea is, when Alec's partner calls in to say there's a crazy homeowner trying to tell him about aliens.
It has been anthologized over a dozen times, turned into two different audiobooks, and Isaac Asimov would include it in four of his collections, such as Earth is Room Enough (1957), Science Fiction Verhalen 3 (1964), The Complete Stories Volume 1 (1990), and Living Space Science Fiction Triple Feature (2012).
Examples of tropes within this work:
- Absent Aliens: [Implied Trope] Since Casual Interstellar Travel technology was too difficult to create, Earth has developed dimensional travel technology instead. Without space travel, nobody expects to encounter any alien life. They were wrong.
- Alternative Calendar: The protagonists use the Anno Domini calendar (possibly with minor changes), but when Alec Mishnoff asks the German-speaking builders he's encountered what year they think it is, he finds that they're measuring time since Hitler's rise to power (Nach Hitler).
- Alternate Timeline: Alec Mishnoff is able to figure out that the German-speaking builders are from an alternate Earth timeline where Nazi Germany won a tribal conflict. Still the same year, ignoring differences of Nach Hitler versus Anno Domini.
- Audio Adaptation:
- Conveniently Unverifiable Cover Story: The Housing Bureau lies to Clarence Rimbro about the other parallel universe Earth colonists, calling them a geological instability that has been fixed. Since they were outside the forcefield, Rimbro won't try to verify the story.
- Decoy Protagonist: Clarence Rimbro, accountant and all-around nobody, is exactly the type of character Isaac Asimov likes to use as The Protagonist in his stories, but once he's gotten the government to listen to his problem, agent Alec Mishnoff takes over as the person resolving the plot.
- First Contact: Alec Mishnoff is relieved when the people he encounters on Rimbro's home (one house to every dead planet earth) are actually humans from another timeline. He, alone in the story, has been fearing that Starfish Aliens will show up because in an infinity of universes, they will. He's horrified to be proven right at the end of the story.
- Deflector Shields: Each home that Earth proper builds is contained in a forcefield that keeps the oxygen atmosphere inside and the mostly carbon dioxide atmosphere and weather outside.
- Interdimensional Travel Device: This Earth developed dimensional travel technology instead of Casual Interstellar Travel, because the technology was too difficult. Homes are built on alternate Earths that never developed life as we know it. Devices are keyed to work with the front door and what is effectively the garage. A unique 'probability pattern' is used to describe each Earth.
- Instantly Proven Wrong: Alec Mishnoff explains how their houses are almost certainly going to encounter alien life, and he's worried about when it'll happen. Department Head Berg is in the middle of telling him how ridiculous the idea is when Bill Ching calls in to report three-eyed tentacled aliens have been sighted.
- Intro-Only Point of View: Clarence Rimbro, accountant and all-around nobody, narrates the first third of the story in third person. Once he's convinced the Housing Bureau to investigate, it switches to Alec Mishnoff and his co-workers in the Bureau.
- Monkeys on a Typewriter: The technology to travel to alternate earths imply an infinite number of said universes. Roughly half of them are not capable of supporting life as we know it, which is still infinity. This Earth developed dimensional travel technology instead of Casual Interstellar Travel, because the technology was too difficult. However, in an infinity of universes, there will be some aliens who have that and not dimension travel. Those aliens may be interested in Terraforming uninhabited planets, which means they'll find the human settlement. The story ends with The Reveal of Starfish Aliens.
- The Multiverse: There's an infinite number of Alternate Universes, and Earth has mastered the ability to travel among them. The overpopulation problem has been solved by allowing people to build homes on an alternate earth that never developed sapient life. An entire Earth for a single home.
- Pun-Based Title: The title has a subtle pun, as it refers to people having larger homes by colonizing dead versions of Earth, each Earth being considered a home, and that a home on a dead Earth is essentially living (in) space. Made more explicit in the first Dutch translation, "Wonen in de Ruimte", which means "Living in Space".
- Recycled Title: The French translation is "Espace Vital", and that name was reused as the translation of the collection Earth is Room Enough as well.
- Starfish Aliens: At the minimum, these aliens have purple skin, tentacles, three eyes, and visible red veins.
- Switching P.O.V.: The omniscient narrator follows characters based on the Anthropic Principle; it starts with Clarence Rimbro's viewpoint so we can understand how the average person sees living on dead planets. Then it shifts to Alec Mishnoff and his partner Bill Ching to establish how the earths are selected and resolve the initial conflict. Then the story jumps ahead in time to when Mishnoff is being debriefed by his local Head of the Housing Bureau, shifting into his perspective to console Clarence Rimbro, before returning to Alec Mishnoff to reveal what he's been worried about the entire story.