Free small house plans, rather than being a rare commodity, were actually quite prevalent in the latter half of the 20th century.
As an incentive to purchase a home, builders would give out free books of home plans to prospective buyers. These books were lavishly illustrated, extensive, and had both attractive exterior views of the houses and correlating detailed floor layouts.
Another avenue for free house plans: house plans publishers. Companies in this niche industry would hire architects and artists to mock up dream homes and sell the plans by mail order. Homebuyers would use these books to dream, fantasize, and come up with rough ideas for their perfect home.
The intent of these free plans was never to build directly from plans. Plan books were a springboard to buying a more expensive set of true, actionable blueprints or to a house contract.
Free house plans were intentionally left vague. For one, the house plans companies wanted to appeal to a broader base of dreamers; highly specific plans did not leave room for personal changes. More importantly, plans were kept hazy so that you could not take them to a contractor and have the contractor start construction from them.
How to Use These Free House Plans
These copyright-free house plans, mainly mid-century style or period, have been re-purposed for today’s use. All of these house plans are free and may be used without seeking permission. In their current state, they are not executable, but you can use them as a springboard for ideas.
In some cases, the layouts have been slightly changed to reflect modern sensibilities. The flavor of these houses has been retained for homeowners who are interested in remodeling—not in demolishing and rebuilding—their older home.
Source: The Spruce