The best museum exhibits mix delight, education and provocation so subtly that the visitor isn’t aware where one bleeds into another. The National Building Museum’s new long-term display, “House & Home,” explores a subject so wide and so fundamental to American life that it inevitably touches the pleasure buttons of nostalgia.

There are places where one wishes the stress were different, especially the environmental costs of building a society premised on homeownership and low-density population dispersion. But the curators have managed to tell a complicated story clearly and engagingly. And they haven’t neglected complex questions about how race, gender and government policy have affected the physical structures we live in and the sentimental structures that nourish us.

The exhibition has been in the works since 1995. During that long gestation came the great economic crisis of 2008, spurred, in part, by risky mortgage lending, which had a tremendous impact on the housing sector. The curators have taken note of the events, with a timeline that marks a 32 percent jump in foreclosures between April 2008 and April 2009, and the devastation of boomtown developments across the country. A photograph of the Foreclosure Express, a bus that shuttled prospective bargain-hunters around the decimated suburbs of Las Vegas, is a painful late chapter in this more than 200-year odyssey.

The timeline gives the most thorough account of other dark chapters in the real estate industry, from government-sanctioned mortgage policies that made it virtually impossible for many African Americans to obtain mortgages to laws in the early 20th century that prevented Asian immigrants from owning land. And, of course, there was the grand theft of a continent from Native Americans. The lingering effect of two centuries of persistent and systematic racism isn’t just seen in segregated neighborhoods. Last year, the Pew Research Center released a report analyzing government data, which made clear one result of this historical pattern: The median wealth of white households is 20 times greater than that of black households.

Unless you read the timeline thoroughly, however, much of this history will stand apart from the experience of the exhibition, like an unpleasant footnote sequestered in the back of the book.

Using photographs, films and a gallery of small- and large-scale models, the bulk of the exhibition focuses on more feel-good fare. The basic contrast between house and home, between physical shelter and emotional nest, is introduced in the first gallery, where rows of photographs display a wide range of house types and the panoply of life that transpires in the home. Two large dollhouses are included, reminding visitors how early the sense that we must have a traditional home, filled with material goods, is inculcated in us. The more curious of the toy houses was made in the 1970s and features parquet floors, globe lampshades, modular storage and abstract art.

Interspersed with the photographs are quotations that give a good sense of the ambiguities and even ambivalence in how we relate to home and house. Homeownership is equated with prosperity and stability. “No man who owns his own house and lot can be a communist,” said William Levitt, the famous real estate developer who gave us Levittown, Pa., a lingering fantasy and nightmare of generic prosperity. But a house is also a burden and can make us isolated monads in a world that needs collective responsibility. Ralph Waldo Emerson made part of that explicit when he wrote: “A man builds a fine house; and now he has a master, and a task for life . . .”