Alain de Botton, the Swiss-born essayist who lives in London, founded a nonprofit group called Living Architecture in 2009 with a simple goal. “I want people to experience modern domestic architecture,” Mr. de Botton said. “What’s lacking in the U.K. are publicly accessible homes. The few modern houses that exist are almost all in private hands and cannot be visited.”The first of the five homes the group has commissioned — all of which will be available year-round for vacation rentals — recently opened to the public.

The Balancing Barn, a gleaming aluminum structure with a mostly plywood interior, designed by the Dutch architecture firm MVRDV, is the antithesis of Victorian architecture with its enclosed, stuffy rooms. Cantilevered over a steep piece of land near Thorington, in Suffolk, the house is nearly 100 feet long, with oversize windows, four bedrooms and bathrooms, and an open living area at tree height.