Breeze blocks are back – just not in Hong Kong. Over the past few years, architectural publications around the world have been trumpeting the return of ventilation blocks, also known as cinder blocks, screen blocks or pattern blocks.
Associated with the sunny modernism of the 1950s and 60s, they can be found in suburban Australian bungalows, Malaysian villas and the restored mid-century motels of Palm Springs, California. Interior designers have even taken to putting them in kitchens and living rooms, where they serve no functional purpose other than as a reminder of a seemingly carefree era of miniskirts and backyard pool parties.
The trend doesn’t seem to have reached Hong Kong, although this city has a well-ventilated history of its own. If you take an eastbound tram down King’s Road, just before it curves around Mount Parker towards the Monster Building, you might notice two concrete screens with an intriguing honeycomb-shaped pattern of openings.
The screens are part of the Ritz Garden Apartments, a four-block building that was completed in 1960. The middle two blocks have been demolished, but the two end sections remain, along with these eye-catching breeze blocks. Ritz Garden takes its name from a ballroom, garden and swimming pool that once stood on this site, which overlooked the harbour until reclamation for the Eastern Harbour Crossing in the 1980s.
The building was designed by Luke Him-sau, who also designed the original Bank of China Building for Palmer and Turner. Although it is a fairly typical apartment block, Luke invested it with a few jazzy touches, including the screens, as well as windows that zig-zag up the façade in a pattern familiar to anyone who has played Tetris.
Although Ritz Garden is a particularly memorable example, you can find breeze blocks on a number of other postwar buildings around town. They run alongside the staircases of Tai Hang Sai Estate, Choi Hung Estate and Sai Wan Estate, which were all built in the 1960s. A mesmerising screen made of thin square frames rises on the northern face of the Tang Lung Chau Market, an unheralded modernist gem in the back streets of Causeway Bay.
Modern breeze blocks were enabled by the invention of reinforced concrete in the mid-19th century. They are mass produced and versatile, giving architects the ability to produce playful geometric patterns without adding much expense to their buildings. Frank Lloyd Wright used them in the walls of the Millard House, in Pasadena, California, which was built in 1923 using concrete blocks.
As modernism spread around the world in the 1930s, 40s and 50s, so did the use of breeze blocks. “The blocks and screens are very much an expression of modern architecture’s functional aesthetics,” says Lee Ho-yin, director of the University of Hong Kong’s Architectural Conservation Programme.
But they aren’t purely decorative. “These blocks and screens provide a porous wall surface for natural ventilation,” says Lee. That is particularly useful in hot climates like Hong Kong. Breeze blocks didn’t just give the Tang Lung Chau Market a distinctive appearance, they shaded its interior while also allowing air to flow through it, keeping its hawkers and shoppers from suffering in Hong Kong’s stifling summer heat.
In that sense, breeze blocks were simply the latest incarnation of traditional screens that go back centuries. Historically, buildings throughout South Asia made use of latticed screens that were carved from stove, providing both a decorative element and a permeable barrier between the indoors and outdoors. The screens filtered the sun while also compressing air as it passed through the openings, increasing its velocity in order to better ventilate the buildings.
Known as jaali, some of these screens are extraordinarily ornate, with patterns so finely carved they seem to be made of lace, not stone. Modern breeze blocks are far more simple in comparison – Andy Warhol soup cans versus the impasto painting of Vincent van Gogh. Both are worthy, but one is significantly more complex than the other.
Breeze blocks began to fall out of favour as tastes changed in the 1970s. A more subdued pace dominated over the upbeat cadence of previous decades. But there was another, more practical reason why these concrete screens began to disappear in Hong Kong: air conditioning.
As climate control became more affordable, natural ventilation was no longer a priority and spaces became sealed in order to keep cold air inside. In a city as densely built as Hong Kong, air conditioning begets air conditioning. “An air-con unit blows cool air indoors and hot exhaust outdoors,” says Lee. “Imagine thousands of air-con units installed at different levels of high-rise buildings in close proximity to each other. Then you get lots of hot air blowing in all directions into the environment, with some trapped between buildings, creating an urban heat island effect, which in turn creates more need for indoor air-conditioning.”
Today, ventilation blocks remain as a reminder of a breezier era. Lee says they have little heritage value on their own, but when considered as part of a whole structure like the Tang Lung Chau Market or Ritz Garden Apartments, they are a “character-defining element” that adds to the value of their building.
Will breeze blocks make a comeback the way they have in other places? Maybe not. When the entire city is a self-reinforcing bubble of heat, it may be too much to expect a revival of naturally-ventilated buildings. But at the very least we could appreciate what little we still have.