A sinuous enclosure that doubles as seating and a shelter inspired by the yin-yang symbol are among the cat houses by Los Angeles architects that were created to benefit an animal welfare organisation (+ slideshow).

The 12 cat houses will be auctioned off online, with proceeds going toward FixNation, an LA-based charity that works to reduce the homeless feline population by sterilising feral cats.

The initiative, called Giving Shelter, was organised by Architects for Animals, an advocacy group started in 2009. A companion fundraising event was held this month in LA, where the cat houses were put on display.

"Architects for Animals invited LA's top architecture and design firms to build and donate creative and functional outdoor dwellings for cats," said the group.

In recent years, high-design objects for pets have become increasingly common. Kenya Hara's ongoing Architecture for Dogs initiative invites architects and designers to create structures for canines, with architects such as Toyo Ito and Shigeru Ban contributing pieces.

Many companies now produce modern pieces for pets, including Meyou's cocoon-like cat beds and a work desk by Hao Ruan that is meant to also serve as a "playground" for felines.

LA design firms that participated in the Architects for Animals initiative included HOK, Pfeiffer Partners Architects, Abramson Teiger Architects, Knowhow Shop and many others.

"The breadth of designs was remarkable," said the organisation. "Some incorporated items such as built-in feeding bowls, toy mice, and even an actual fishbowl with live fish."

This is the second time that Architects for Animals has hosted the event and auction in LA.

Douglas Teiger, co-founder of Abramson Teiger Architects and a longtime cat owner, has participated both years.

His firm's entry, Cat in the Fish Bowl, won the 2016 people's choice award. "Our office staff had fun designing and building this year's entry," he said. "Winning the people's vote award was icing on the cat."

The studio's design was inspired by the Chinese symbol for yin-yang, which "represents the dichotomy between opposite energies and how they are connected and interdependent, just like the cat and fish".

"The fish make up the form while the cat rests inside," the firm said of its design. "The layers of the structure are spaced apart to allow the cat easy viewing out of the house while remaining safely hidden within it."

CallisonRTKL created an enclosure titled Silhouette, which consists of a sculptural arrangement of wooden slats.

"Our design plays off of a cat's mysterious personality," the firm explained. "Our structure's contemporary interpretation and progressive materiality link a cat's personality to a modern design aesthetic."

The shelter called Cat-à-Tête was created by the design studios Formation Association and Arktura, along with the engineering firm Buro Happold.

The enclosure was constructed of a sheet material made of recycled plastic bottles. "Despite its constitution, the material is soft and possesses tactile properties similar to felt," the designers said.

The shelter features several openings that enable cats to hide from predators, along with areas for rest, play and observation. Its S-shaped form enables face-to-face conversations.

"The structure provides a social framework for cats and humans alike," said the design team.

In addition to the shelters, the fundraising event held this month showcased cat-centric products and home decor, including food bowls decorated by celebrities such as Clint Eastwood, William Shatner and Betty White.

Architects for Animals was founded by Leslie Farrell, who formerly worked at a design firm. While living in New York, she constantly saw homeless animals and wanted to help.

"I have always been a fan of architecture, design and artists," she said. "I decided to devote my efforts to creating an organisation that would bring these worlds together and ultimately provide new ways to raise awareness and help animals that are suffering."

FixNation sought her help in coordinating a fundraising event. "The response has been wonderful," said Farrell. I love working with the LA design community. They are fantastic."

Photography is by Meghan Bob Photography.