Retrofitting buildings so that they consume less energy is key to meeting current climate targets. A company in Germany is working to accelerate that process by building tailored facades with built-in insulation that can fit like a glove onto old buildings to reduce their energy use.

Prefab insulation panels

The facades consist of prefab panels that are molded to fit exactly on the walls of old apartment buildings. The aim is to solve one of the biggest challenges of decarbonizing our built environment, which is that current retrofitting techniques are excruciatingly slow.

As things stand now, it would take Europe five centuries to transition each one of its existing buildings to net-zero. In the US, things are likely to be even slower. As the world aims to reach net-zero by 2050, the current building stock requires a fast-retrofitting process.

Creating digital twins of old buildings

Now that’s exactly what Ecoworks, the German startup behind the new system, wants to provide. The startup uses artificial intelligence to identify the buildings that consume the most energy and that are suitable for its retrofit technique.

The company then makes a 3D scan of an old building — from the inside as well as the outside — to create a digital representation of the structure. “If you have a digital twin, you can actually automate planning, which, in a normal renovation, would take months and a lot of engineers and architects,” says founder Emanuel Heisenberg.

Once they have the digital twin of a building, the company sends the plans to a factory, where robots build everything in advance. Each panel includes windows, ventilation, and channels for pipes. They also build modular roofs, which are integrated with solar panels.

How long does the retrofitting take?

It takes about 20 minutes for on-site workers to install a panel. Retrofitting an entire apartment building, including replacing fossil fuel heating, can happen in weeks. That’s compared to the months or even years it takes to convert a building with traditional retrofitting techniques.

Heisenberg was inspired by a similar modular system for retrofitting buildings in the Netherlands, which we wrote about back in January. He approached a number of construction companies with the idea, but none of them were interested. Seeing that most in the industry are reluctant to change from the status quo, he decided to start his own company, automating the process as much as possible.

Turning buildings into energy generators

Now buildings that have been retrofitted with the Ecoworks system are reaping the benefits of a much lower need for energy use. One 12-unit apartment building from the 1930s used to consume 450 kilowatt-hours of energy per square meter before renovation. Following the retrofit, the building now actually generates surplus electricity that it feeds into the grid. “After renovation, we have negative emissions,” says Heisenberg.

Since the modular facade is made from wood and reuses most of the building for retrofit, the construction process has a very low carbon footprint. According to an estimate by Heisenberg, it would take no more than two years for a building to offset the emissions associated with the renovation process.

The company is now working on seven apartment buildings and plans to rapidly scale up its process in the coming years. While currently it mainly focuses on apartment complexes, the plan is to expand its process to schools and eventually single-family homes.

In Germany alone, over 30 million houses will require retrofitting in the next 25 years for the country to meet its climate targets. With smart systems like modular facades, reaching that target may actually be possible.

TOD Editor: Watch Emanuel Heisenberg’s ECO21 Berlin presentation on the Ecoworks program to learn more.