Many of Miami’s art deco gems are subject to stringent historic preservation restrictions — which is wonderful for design history buffs. Hotels and motels are constantly getting revamped, which means they’re not just retro-chic but up-to-date, too; here are seven worth a stay. (Bonus: they’re all relatively inexpensive, too!)

Built: 1940; reopened: November 2015; from $139.

Coolest original detail: The original Haddon Hall sign from the property’s old days, plus a pair of vertical neon racing stripes. Unlike many other hotels with newer aquatic additions, this pool is original — and it’s one of the biggest in South Beach.

Best new amenity: “Top Chef” alum Spike Mendelsohn’s restaurant and juice bar, Sunny’s, as well as poolside parties spiffed up with live music and oversized animal-shaped rafts. Then there’s newly opened beer garden Campton Yard, which has craft cocktails, colorful lawn furniture and a ping-pong table.

Built: 1941; reopened: December 2012; from $199.

Coolest original detail: Architect L. Murray Dixon’s asymmetrical facade with one rounded corner and a vertical racing stripe. Look for the pink stone border over the Collins Avenue entrance, and geometric, jutting-out “eyebrows” over windows.

Best new amenity: A $35 million makeover added a pool and bar on the rooftop as well as new-yet-retro additions like the black-and-white photographs of Miami in the ’40s and ’50s that line the 112 guest rooms, hallways and social spaces.

Built: 1960s; reopened: May 2015; from $151.

Coolest original detail: Formerly the Motel Ankara, the 235-room hotel maintains the vintage sign from that era, protected by South Beach’s stringent historic preservation codes.

Best new amenity: A new eight-story tower — which matches the motel’s white-and-orange color scheme and rises behind the old motel — is the most obvious sign of modernity, but contemporary touches abound. There’s a cavernous industrial lobby, bright pink foosball tables by the pool and street art-style works.

Built: 1950s; reopened: December 2015; from $195.

Coolest original detail: “Miami Modern” architect Morris Lapidus, known for the massive Fontainebleau hotel to the north, built a “stairway to nowhere” in the lobby. A landmarked feature, it used to lead to a hidden powder room and coat check, as well as offer a place for guests and celebs to make a grand entrance. Now, it just winds into the wall — but it sure is cool to look at.

Best new amenity: A saltwater heated pool with an underwater surround sound system, plus the adjacent cabana club.

Built: 1948; reopened: January 2016; from $139.

Coolest original detail: The blue trim on the undulating facade and a matching blue sign with the hotel’s name — which references Puerto Rico’s capital — and glows red at night. (The hotel, which was designed by Henry Hohauser, is technically in a postwar modern style.)

Best new amenity: One hundred round brass light fixtures dangle over a long, brand-new lobby bar.

Built: 1940; to reopen: September 2016; from $250 (subject to change).

Coolest original detail: Outside, a distinctive, angular slender pylon, which houses an elevator shaft on the inside, towers above the low-rise. Inside, two jewel-toned murals in the tropical modernist style by artist Roman Chatov, whose works graced the 1939 World’s Fair and the Russian Tea Room, light up the rounded lobby.

Best new amenity: The original street-level terrace is being revived with swinging benches and potted palms. Meanwhile, the folks behind sushi hot spot Blue Ribbon will run a restaurant, offer all-day lobby dining and serve bites at the pool.

Built: 1940; to reopen: late 2016; rates to be determined.

Coolest original detail: Architect Albert Anis’ glorious facade will lose its funky colors but be restored to its former state: a gleaming white. It will retain its funky sculptural quality.

Best new amenity: Behind the short 76-year-old structure, a new 10-story tower with a rooftop garden, pool and restaurant is rising, which will increase the hotel’s capacity to 96 guest rooms. The new additions, as the photo shows, will be glassy.