# CTA Designs Annex in Vietnam with Curved Roof to Evoke Cave Sensation CTA studio creates a unique design that brings nature into the living space. - **Source:** [Architecture news and projects | Dezeen](https://brifing.si/source/50c21201-9cc6-48e0-8a7c-6ea605af10c3) - **Published:** 2026-07-27 - **Topic:** [Design & UX](https://brifing.si/c/design) - **Original article:** - **On Brifing:** https://brifing.si/s/36d17f86-89c5-4535-9aea-fdeba9ba05d9 ## CTA's New Project in Vietnam CTA studio has designed an annex for a house in Phu My, Vietnam. Named Casa Mac, the structure was conceived as a large, singular living space. The design is built around the idea of bringing nature into the interior. The building is surrounded by a vegetable garden and a koi pond. This approach aims to create a natural atmosphere while minimizing traditional home elements. ## Roof Design Evoking Cave Sensation The most striking feature of Casa Mac is its curved, canopy-like roof. A long skylight runs through the center of the roof, and the light entering through it is filtered by perforated metal screens. CTA co-founder Nguyen Thanh explains that this design aims to evoke the sensation of being in a cave. The roof unites daily human activities and natural elements under a single shade canopy. ## Natural Materials and Minimalist Approach Casa Mac's design incorporates raw and rustic materials. Exposed brick walls are complemented by a ceiling made of narrow wooden planks. The roof is covered with scale-shaped bitumen shingles. This material choice enhances the building's harmony with its natural surroundings. Partition walls and doors are kept to a minimum to create an open space feeling. ## Functional Layout of the Interior Casa Mac's interior consists of a large area divided into different zones. The central area is segmented by green spaces. Two wide sets of steps connect the lower living, dining, and kitchen area to a slightly elevated workspace and jacuzzi. To the west, stone steps lead across the koi pond to a parking area. ## Connection and Transitions to the Main House The annex is connected to the main house via two small pathways at the front and back. These pathways ensure seamless transitions while keeping the daily activities of the two households distinct. Narrow arched openings in the brick walls provide easy access to the main house. This design maintains connectivity while preserving the independence of both homes. ## Rest Room and WC Area Instead of a traditional bedroom, Casa Mac features a rest room next to the WC. This area is designed as a temporary spot where friends can take a quick rest or sober up. This approach indicates that the building is not used as a conventional residence and offers a more flexible living space. ## CTA's Previous Projects CTA studio previously designed a narrow house in Bien Hoa. In that project, folding doors and perforated screens were used to control light and ventilation. Additionally, the studio has a project featuring a house clad in reused scallop tiles. These projects showcase CTA's expertise in natural materials and innovative designs. ## Architectural Significance of Casa Mac Casa Mac stands out as an example of design that brings nature into the interior and reinterprets traditional home elements. With its curved roof, exposed brick walls, and natural materials, this structure emphasizes the importance of creating living spaces in harmony with the natural environment in modern architecture. CTA's project offers a fresh perspective in architectural design. ## Sources covering this story - https://www.dezeen.com/2026/07/27/cta-casa-mac-annexe-vietnam/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._