You may think that a library has to be its own room, but books can be stored and read just about anywhere. Lining a hallway with books turns it into a library that you’ll walk through, and be inspired by, every day. Cabinets below provide extra storage and even a place to sit and read.

In the flat’s living room, midcentury modern art and furniture harmonize with the rich floor tiles, opulent molded ceilings. and original pine wood doors. Prints by Gordon Matta-Clark line the wall near a 1950s Danish dining table that’s paired with Eames chairs. A painting by Kuuti Lavonen hangs above a pink chair and ottoman by Ronan and Erwan Bouroullec.

The architects’ two young children occupy this bright bedroom, furnished with Ikea beds. Another custom lamp illuminates the space.

In the living room of the Barcelona apartment designer Elina Vila D’Acosta-Calheiros shares with her husband, Ginés Gorriz, Arne Jacobsen Swan chairs join a sofa by Piero Lissoni for Living Divani. The cabinet is from Cappellini, as is the Marcel Wanders Big Shadow lamp.

The main living area is connected to the back unit by a modern bridge. Polished concrete is used for both floors and ceilings, and a Mies van der Rohe Barcelona Stool accents the space.

A side view of the house and of Salmela’s signature architectural feature: the “unchimney.” All windows are from Loewen.

In 1910, when the building was constructed, Barcelona’s economy was booming and, as a result, so were the arts. Architecture was especially popular among the city’s wealthier citizens, and splendid buildings were built in the new neighborhood of L’Eixample, on the edge of the old, Gothic city center.

Two art studios adjoin a central volume at this work/live residence built from terracreto (sustainable concrete), glass, and painted steel just outside of San Miguel de Allende, Mexico. Residents Austin and Lida Lowrey, retired design and museum professionals, collaborated with their two daughters—Sheridan, an artist, and Elizabeth, an architect—to design the structure as a place for creative contemplation.

Day, Hachigian, and Sosi congregate on the back terrace at a dining table designed by Day and his brother-in-law, Garo Hachigian.

In the marble-paved bathroom, the architects employed a simple trick to get the most out of the small space. Since the ceilings were already high, they raised the floor level about two feet to fit a Dornbracht bathtub beneath the shower. “By doing so, we also gained a storage space under the bathroom floor, and the window, without moving it, suddenly was in the right place!” Eugeni says. The shower head and sink are by Duravit.

Since the original kitchen was not functional, the architects built a new one from scratch while preserving the original tiles. “We designed very plain oak cupboards so the floor would be the protagonist,” Eugeni says. Ceiling lamps by Vico Magistretti illuminate the warm wood countertops.

A glazed veranda on the flat’s west side offers a cozy spot to enjoy an espresso. The utilitarian table and chairs were purchased second-hand, while the lamp was custom designed.

The backyard sports a sequence of raised flower and vegetable beds and two green roofs—one atop the workshop and other atop the back entrance.

David Garcia, head of the Institute for Architecture and Technology at the Royal Danish Arts Academy in Denmark, says we should fully integrate technology into building design. He calls out the Media TIC building in Barcelona by Cloud 9. "The building uses new technology not as a gimmick, but as a new way to mitigate environmental challenges," he says. "The building fine-tunes its facades to shield itself from light and thermal heat from the sun."

A slender, black double-sided fireplace distinguishes the living room from the dining area.

A graphic wallpaper by Kate Zaremba wraps the kids' bathroom with sconces by Allied Maker.

For architect Stephen Chung, the design of his Wayland, Massachusetts, home was all about blending into the natural environment. The first floor is a serene composition of white and wood. The demand for a domestic office space inspired him to build up, adding a second floor for him to "experiment." In a departure from the Cape Cod aesthetic that rules his block, he was able to give the addition a modernist take, while also literally reflecting the existing landscape of the neighborhood. The entire 1,100-square-foot adjunct that encompasses his second story office-studio, master suite, and fort for his two young sons is swathed in mirrored siding and plate-glass windows.

Two dozen specialized flavors are posted each day on the chalkboard.

Tribeca Manufacturing Building New York–based architect Andrew Franz undertook the renovation of a landmark circa-1884 former soap warehouse in Tribeca, originally designed by George W. DaCunha in the Romanesque Revival style. Franz reorganized and modernized the six-story building—which retains its original 16-foot beam ceilings, brick walls, timber columns, and elevator winches from the former freight shaft—by incorporating steel, glass, handmade tile, and lacquer to complement the masonry and heavy timber. An interior courtyard and rectangular mezzanine are situated below the original 16-foot gull-wing ceiling planes.

Understated décor in the master bedroom lets the floor tiles fully pop. A pendant lamp designed in 1957 by Spanish modernist architect José Antonio hangs above the bed.

The exterior of the new, two-story home in East Austin, Texas was designed with a minimal palette, bronze windows, and steel details in order to blend into the existing cityscape.

Bestor opened up the central spine of the ranch-style home, creating a kind of longhouse with the ceilings insulated and covered with hemlock.

This sophisticated credenza is a streamlined storage system that is available in a variety of configurations. It can be used as a buffet or sideboard in a dining room, media console, or cabinet in a bedroom. Other credenzas include the 4 Drawer and 4 Door. Similar designs include the 2 Door 2 Drawer File Cabinet, 4 Door Cabinet, and Dresser.

The sleeping cubbies lie beneath the walkway connecting front and back units. Cedar decking and soffit add warmth and texture to the transitional space.

The home's indoor/outdoor connection is strong.

Despite a tight site, light floods into every room, including the restroom in the guesthouse.

Layer by layer, a crumbling 18th-century flat in the middle of Barcelona finds new life at the hands of architect Benedetta Tagliabue. Paths of Andalusian tile and intervening plaster walls help to delineate space in the expansive apartment, which is centered around an internal entry courtyard. The armchair, designed by Peter and Alison Smithson, is covered in a Josef Frank textile from Just Scandinavian. The white piece just behind it is a repurposed Austrian stove that’s now used as a storage device.

The tiered side table was designed by Jasper Morrison.

The family’s two cats, Baron and Jula.

In the kids bathroom, Ceramica Vogue tile in multiple colors brings a youthful quality. Countertops are by Concrete Collaborative.

Airy living room.