In order to achieve the environmental and climate objectives in 2050, we must now make all the necessary preparations to accelerate large-scale renovation of existing buildings. At present, less than a thousand buildings are made energy-neutral or positive every year. There must be a thousand of them a day in order to meet the 2050 targets. TNO is working on technological and organisational solutions to accelerate the renovation process.

As a result, it should be possible to make no less than 30,000 to 50,000 homes sustainable per year in a few years' time, and then eventually to reach around a thousand per day after 2025. In order to realise this ambition, there is intensive cooperation with the business community, such as manufacturers, installation and energy companies. Municipalities also play an important role in this context.

Scalable and affordable

The approach envisaged by TNO to accelerate renovation has a number of components that are mutually reinforcing. First of all, it is about mapping out the entire built environment. What type of home, office building, school or healthcare property is involved, in which year was it built, type, materials, insulation, installed equipment. Next there are concepts for each type of house for how the renovation can best be achieved in terms of time and money. In addition to the energy aspects, comfort, a healthy indoor environment, ease of use and durability are also important. The most important thing is that the structural adjustments to homes are scalable and therefore affordable. Far-reaching digitisation of the building process is indispensable in this respect.

Digitising the building process

Building Information Modeling (BIM) can be used as a starting point. This is helping the building sector to move from paper-based documents to digital processes. Design, drawings, planning, costs, materials, suppliers involved: everything is available digitally. At the moment, all these steps are taking place separately. By linking all life stages of building, from design to demolition, the envisaged renovation process can be considerably simplified and accelerated. This makes it possible to standardise the process, while within it variations can be made fairly easily ('customised mass production'). Residents have the freedom to choose to deviate from standards. This also contributes to the acceptance of adapting the home.

Industrial integration

The building process will undergo radical changes in the coming years. Whereas it is now customary for installation engineers of different facilities to work independently in a house, this work will be integrated industrially in a single process. In new buildings, it is already common practice to produce as many building components as possible in the factory so that less work is required on the building site itself. TNO, together with its partners, also wants to make this possible for renovation. In the future, for example, entire streets or complexes will be fairly easy to tackle. Pipes, connections and equipment such as heat pumps are also part of this concept.

Sustainability and business

The combination of large-scale industrial prefabrication offers new opportunities for entrepreneurs in the building industry. It cuts both ways: the built environment is accelerated to become sustainable and the building sector is given a new impulse. The intention is to have this new concept operational in about five years' time and then to roll it out across the country on a much larger scale.


Frits Verheij, MSc

  • Energy Transition