Rooftop Garden House In Heart Of Tropical City

Design by: VTN Architects.

Located: Da Nang, Vietnam | Latitude: 16.0338˚ N

A rooftop garden house is a great idea in the tropics. Green roofs or rooftop gardens in a house replace some or all the land space the building takes up. Hence, this makes them an environmentally friendly and sustainable response.

Project and Context

“Thang House” was constructed in 2019 and is situated in the heart of Da Nang City.

Da Nang is the third-largest city in Vietnam by urban population and has one of the fastest-growing populations in the country. It is a coastal city in central Vietnam and has a tropical monsoon climate.

It sits on a 250m² lot and has a gross floor area of 250m² (2,691 sq. ft.).

House Design Concept

The concept of this house came from a childhood dream of the homeowner. They desired to own a “country house, full of rich tropical greenery, grassland and fresh air”. However, they wanted it in the heart of Da Nang City.

Photo: Hiroyuki Oki

This home is part of a series of houses that VTN Architects refer to as a “House for Trees”. They are a means of counteracting the rapid urbanization of Vietnamese cities. As a result, these houses try to introduce as much tropical greenery into the city.

Green Wall and Garden

The architect came up with the idea to create a “green lung” for the house. Their strategy was to create a garden area, which they called a green lung. Hence, they divided the land into two parallel portions. One side is the green lung with a garden, swimming pool, fishpond and a massive green wall.

Photo: Hiroyuki Oki

The other side of the property contains the main living spaces of this rooftop garden house. Most of the windows and doors face the green lung. Therefore, this creates a strong connection with the outdoors. Not only do the family see the plants and water, but they also get to smell and hear them.

“…majority of its windows & doors facing towards the green lung with the purpose of bringing natural light, fresh air and the aroma of grass and flowers to every single corner of the house.”
– VTN Architects

Rooftop Garden

As previously mentioned, green roofs help replace part of the land area that the house occupies. Thang house does precisely that.

A rooftop garden house has great benefits. Roofs usually have the most exposure to sunlight on the property, which is excellent for most plants. Furthermore, they help protect the house below from the sun’s heat. The soil, plants and trees help prevent heat from passing through to the inside.

Photo: Hiroyuki Oki

Nine planter or tree boxes are in this rooftop garden. They are parallel to each other, with a space between them. The spaces between perform two main functions. Firstly, they permit views to the roof garden from the areas below. Secondly, they also allow natural light to permeate through the leaves of the plants to the spaces below.

Photo: Hiroyuki Oki

In addition, what is terrific about the roof garden on this house is that it is not just a regular green roof with grass and shrubs. Here, the trees and plants are food-bearing and consist mainly of fruit trees.

Therefore, this roof garden does not only contribute to the greening of the city. It is also a great example of a space for urban agriculture. Fresh tropical fruit and vegetables are harvested regularly for the family.

“The perfect combination of farming with a panorama view of an emerging coastal city would surely relieve a person from the burden of a hectic city life.”
– VTN Architects

Sustainability

Along with the ample greenery that this house adds to the site and city, it also incorporates other sustainable features. These allow the house to operate more efficiently and economically as well.

An automatic watering system recycles water from the fishpond. The water circulates from the pond to the rooftop garden and vice versa. When rain falls, excess water from the tree boxes goes to the fishpond via a filtration process. Water from the fish pond also comes up to the planter boxes for irrigation and provides the trees with nutrients. This process produces an efficient closed-loop system.

Solar water heating, as well as solar panels, produce hot water and energy for the home. They are in one of the nine tree boxes.

The design of the house allows plenty of natural light and ventilation. Hence, not a lot of artificial lights or air conditioning is needed.

“The design aims to make the building self-sufficient in green food production and to minimize energy consumption.”
– VTN Architects

In an interview with Yit, the client expressed that generally, most children are more familiar with high-tech gadgets. However, her three sons are close to nature. They enjoy swimming and gardening because of the house.

House Design Layout

“The house comprises of four main boxes – one big volume under the roof and three smaller inside the big one. These are extended and hanged over the garden to make space for bedrooms and living room.”
– VTN Architects

On the ground floor (or first floor in North America) they are two bedrooms. One of the bedrooms is in the first box. The side of the bedroom box that faces the green lung garden has a glass sliding door with bricks on the outside. These bricks provide privacy and security while allowing natural ventilation.

As you go up to the second floor, you land on the roof of the bedroom block below. This landing becomes a large open area with an outdoor space. It leads to the living and dining rooms as well as the kitchen.

Photo: Hiroyuki Oki

The master bedroom is on the third floor in the third box. An outdoor terrace space is off the bedroom.

Photo: Hiroyuki Oki

From this terrace, a spiral staircase takes you up to the rooftop garden.

People who move around the house travel through different types of spatial, in-house atmospheres. Since the boxes project in and out of the larger box and garden area, it creates various quality spaces.

According to where you are in the home, you can experience single, double and even triple-height spaces. The interaction from room to room and the natural environment provides various levels and experiences.

The narrow gaps between the tree boxes on the roof garden bring daylight and moonlight into the spaces below. This light is subtle but sufficient for the interior spaces. It creates a playful effect with light that you experience on all three levels.

Construction And Materials

“While the big box is covered by greystone for a deep and charming feeling of the common space, the small ones are covered by white brick for an enlightening and warm feeling of living space.”
– VTN Architects

The house uses locally sourced building materials. They tried to use nearby sources. Hence, the grey stone came from the Hoa Son rockery mine in the city, and the bricks are from the nearby province of Quang Nam.

In addition, exposed concrete is an efficient material for low-tech construction in Vietnam. It is also durable against the harsh climate of the region.

Materials, construction methods and the play with form and volumes create this stunning tropical modern home. Furthermore, it incorporates design strategies for the tropics.

Conclusion

With the rapid urbanization of Vietnamese cities, there is a lack of greenery.

As a result, it generates various urban problems. These include increasing air pollution and the inability to retain rainwater.

The architects, through houses like Thang House, pledge to contribute to the city’s greening. Their houses encourage biophilia. They aim to provide sustainable homes that are friendly and responsive to the environment. The rooftop garden in this house does that.

“Thang House is yearly covered by tropical fruit trees which creates a tranquil, peaceful space for every family member and simultaneously preserves a green corner in the middle of this rapidly developing city.”
– VTN Architects