Proposed Paris Building Renovation is Really Out There

French architect Stéphane Malka has a very interesting proposal for how to renovate an old apartment building in Paris. Plug-in City 75, as the project is named, calls for attaching a series of wooden boxes to the building’s façade, which will have the dual function of increasing the interior space of the apartments, as well as make the structure more energy efficient.

Malka came up with this idea because the local building codes do not allow for extending buildings upward, but extending them outward is allowed. He has already designed the wooden boxes to be used for this purpose. They vary in size and are all prefabricated off-site. The building that is to get this interesting facelift is located in Paris’ 16th arrondissement, and was build in the 1970s.

The prefab boxes to be used will be lightweight, and built using sustainably-sourced wood. Plans call for them to be mounted onto the building’s facade. The occupants of the building will be able to decide what they want to use the added space for, such as a lounge, balcony or a loggia. The renovated building will also have a green façade, thanks to the greenery planted along the boxes.

According to Malka’s calculations, these new additions to the façade will reduce the building’s energy expenditure from the current 190 kWh per sq m (10.8 sq ft) per year to 45 kWh per m2 (10.8 sq ft) per year. That’s quite a reduction, and it will be interesting to see if these numbers are achieved in practice. The Plug-in City 75 project will be completed mid-2018.

Overall, this is a great example of an old building renovation done right. This project will boost energy efficiency and create larger living spaces in one go, which should be the goal of urban renovation projects worldwide, if we are to successfully reduce our carbon and energy footprint.

The City of Nanjing Will Soon Get a Vertical Forest


When architect Stefano Boeri first came up with the concept of the so-called Bosco Verticale (Vertical Forest), that is two skyscrapers clad in greenery, many people believed it would remain just a concept and never see the light of day. But now, a third Vertical Forest is to be built in Nanjing, China.

The Nanjing Vertical Forest, as the project is called, will consist of two skyscrapers rising from a shared podium. One will be 656 ft (200 m) high and the other 354 ft (108 m). Apart from apartments they will also house a hotel, office space, a green architecture school, restaurants, a conference hall, an exhibition spaces, and retail space. The taller skyscraper will also have a private club on the roof, and the smaller one will have a rooftop swimming pool.

Together, the buildings will be clad in 600 tall trees and 500 medium-sized trees that will be sourced from 23 local species. The façade will also feature 2,500 cascading plants and shrubs in concrete planters that will be integrated into the units’ balconies. It is estimated that all this will absorb 25 tons of CO2 annually, an produce around 132 lbs (60 kg) of oxygen per day.


A lot of concrete will be used to construct the towers, so it’s still debatable just how sustainable these Vertical Forests actually are. But giving city dwellers a chance to have a garden in their apartment will definitely improve their quality of life.

The Nanjing Vertical Forest is being financed by the Nanjing Yang Zi State-Owned Investment Group and will be completed by 2018. Boeri is also busy improving his original designs for the Vertical Forest and hopes to see more of them built around in China in the near future, in cities such as Shijiazhuang, Liuzhou, Guizhou, Shanghai and Chongqing.

Naturally Cooled Concrete House

The Vietnamese firm Vo Trong Nghia Architects recently completed the so-called Binh House in Ho Chi Minh City. While it is made of concrete, which is not the most sustainable material, they have found a way to cool it naturally. It also has many plants softening up its façade, which makes it a welcome island of greenery within the city. The firm is planning to build other such houses as part of their House for Trees series.

Binh House measures 2,507 sq ft (233 sq m) and is comprised of three floors. All the areas of the home are carefully arranged to allow for privacy. In an effort to keep the interior cool they also put a lot of thought into the layout of the rooms. Thus, the kitchen, bathrooms, stairs, and corridors are located on the west side of the home, and shield the living room, dining room and bedrooms so that they are kept naturally cool. This is also achieved by the ample greenery and the stacked layout of the house, which enable the pressure imbalance between the air inside and outside to be drawn in automatically and thus aid ventilation. The latter is also aided by the many sliding glass doors they installed. An AC is installed, but according to the architects it was not needed since the home was completed in 2016.

The greenery that covers the exterior includes a fruit tree garden on the roof, as well as a terraced vegetable garden along the façade. The plants are planted in planters and also give the occupants privacy. There is also an indoor garden in the lounge, and a small garden in the home’s courtyard.

While using only concrete to build a house in a hot and humid climate such as the one in Ho Chi Minh City might not be the best idea on paper, the architects seemed to have made it work in this case.

Unique Approach to Increasing the Sustainability of Old Buildings


Belgian architect Vincent Callebaut has recently come up with an interesting and unique solution to turning an old, 1970’s apartment building into a very sustainable complex. His plans call for the transformation of the existing concrete structure into an energy producing building with a green façade.

Callebaut would leave the building as is, but would add 274 planter beds into its ornamental façade. These would hold about 10,000 plants carefully chosen by botanists, to create a sort of vertical garden or green façade, which would increase the building’s thermal performance and clean the air. According to Callebaut’s calculations the plants would capture 50 tons of C02 per year. The windows of the apartments would also have to be exchanged for energy saving ones to further improve the thermal performance of the building. Keeping the green façade flourishing would not be difficult at all, since there would be a drip-feed system that would require maintenance only twice a year.


The second step in the renovation of this building to make it more sustainable would be the installation of a structure called the Chrysalis, which would be placed on the roof. A large solar panel array and 42 wind turbines would cover the top of the Chrysalis, which would produce an estimated 128,340 kWh of energy per year. This would offset the energy needs of the building considerably. The Chrysalis itself would be made of timber and steel and could be used as retail or office space, or extra residential space.




The project is quite ambitious, but it would make this particular building nearly independent of the power grid. It’s still in the design stage though, and there’s no word yet whether it will ever get the green light.

Self-Sustaining Vertical Garden


Vertical gardens are great for façades, insulation and to add a bit of greenery to a home or office. But the problem with them is that they require a lot of maintenance and power to flourish. Well, that could be a thing of the past. The firm Treebox, which specializes in urban greening, has created a vertical garden, which is entirely self-sustaining. It needs no power and gets all its water needs taken care of by rainwater, hence its name—Rain Garden.

The vertical garden pictured above is located in London. The rainwater needed to irrigate it is collected in tanks, which are hidden beneath the greenery. Instead of a pressurized irrigation system typically used in such gardens, this one uses a “wicking rope” to water the plants. This works by allowing the plants to absorb the water they need through a capillary action.

The plants are therefore irrigated in a controlled way so that they do not get too much water too fast. The system is also capable of reducing the water supply to the plants when there is high rainfall, while a tank filled to capacity can sustain the garden for up to six months.

This Rain Garden is an excellent solution for use in areas where servicing them is not easy. The gardens are planted with mostly evergreens, such as ferns and mosses, or more precisely Asplenium, Polystichum, Carex Elata, Sarcococca and Geranium.


The Rain Garden in the UK was installed about 2 years ago as part of the Drain London sustainable urban drainage program. It has proven to be so successful, that they recently extended it to measure 96 feet (30 m) meaning they tripled its original length. Hopefully more urban areas will consider adopting this approach to drainage in the near future.