Green energy at the heart of the Rout Lëns district

We are increasingly aware that we are living in a period of transition where global environmental issues are challenging individual interests.

In addition to the energy and environmental transition, we are facing a rapid evolution of our lifestyles, the way we live, eat, work, build and even travel.

In this context, from the very first sketches, it has been essential to place sustainability issues at the center of the Rout Lëns project.

Energy management has become one of the pillars of the philosophy of the new Esch district. It is an integral part of the sustainable approach applied to the whole project.


Our ambition: A 100% neutral district!

When it comes to energy, there’s no question of going easy on it. Our ambition is to use no fossil fuels in order to achieve near-zero CO2 emissions throughout the neighborhood.

To achieve this, we have designed a unique clean energy mix. This will ensure the supply of electricity and heat to users without using gas or oil!

In addition, since the architectural and urban design was conceived to reduce energy demand as much as possible upstream, consumption needs will be reduced compared to a traditional district.

Rout Lëns, a 100% neutral district
Rout Lëns, a neutral district.


An optimal energy mix

Finding the most favorable energy mix was not easy. That is why the district was the subject of a detailed conceptual energy study. This allowed us to establish a strategy that was perfectly adapted to the specificities of the site and to the legal obligations.

The energy approach adopted is a bottom-up approach. It is based primarily on limiting energy needs at the base and then selecting green technologies adapted to the residual needs. The inhabitants and users will thus be able to benefit from maximum comfort while limiting the environmental impact.

The planned distribution is as follows:

For electricity:

  • Conventional electricity network: 85%
  • Photovoltaic: 12%
  • BIPV (Building Integrated Photovoltaics): 3%

For heat:

  • Air/water heat pump : 40% of the total
  • Geothermal heat pump: 40% of the total
  • Grey water heat recovery: 10%.
  • Centralized wood boiler room: 10% (This is the only item that emits CO2, it will cover peak heat demand)


Innovative technologies for a forward-looking neighborhood

Among the energy solutions planned in Rout Lëns, some are worth mentioning.


The BIPV or when the windows produce electricity:

BIPV stands for Building Integrated Photovoltaics. This technology aims to replace certain building materials, mainly glass, with photovoltaic cells. Each glass roof or window thus designed captures solar energy to produce electricity!

Adapted to urban areas, BIPV makes it possible to take advantage of the enormous potential offered by the facades of office or apartment buildings. It completes the electricity contribution of traditional photovoltaic panels placed on the roof.

These new innovative materials are particularly aesthetic and allow architects to express their creativity while promoting renewable energy.

Everyone wins!


An urban network with 2 types of heat pumps:

After the sun, the air and the ground provide us with two particularly interesting sources of inexhaustible green energy. To exploit them, air-water and geothermal heat pumps (PAC) will be installed.

The air-water heat pump draws calories from the outside air to inject them into the building’s heating system. The geothermal heat pump, on the other hand, uses the energy of the earth’s subsoil where the temperature remains relatively stable throughout the year. The strength of the Rout Lëns geothermal network lies in the use of 5 underground parking lots. These will be used for the meshing of medium depth “basket” probes.

In addition to the advanced technologies, the heat supply of the lots will be done via a centralized district heating network. This will mainly provide heating for domestic water, since the buildings, which are perfectly insulated, are designed to be passive.

This district-wide networking offers a double advantage. First, it allows for the distribution of expenses, such as maintenance. Second, it smoothes consumption according to the periods and needs of the various activities (offices, shops, homes, etc.).


Heat recovery from wastewater:

In Rout Lëns, nothing will be left to chance to reduce heat production at the source! Did you know that when you take a shower at 40°, the water evacuated still has a temperature of 35°?

By recovering the residual heat from it and re-injecting it into the water heating system, it is possible to revalue a substantial amount of heat energy.

In our new district, the contribution of this instantaneous heat recovery from grey water is estimated at 10%.

Ressources, techniques and architecture specific to the Rout Lëns project
Ressources, techniques and architecture specific to the Rout Lëns project.


Limit the need for energy upstream

This energy mix will be all the more efficient if the architecture and urban planning have been designed to limit energy needs!

We know today that architectural and urban planning choices have a major impact on the energy performance of buildings and neighborhoods. They fundamentally influence heating and electricity needs. For example, access to natural light avoids the untimely use of artificial lighting. Vegetated or shaded areas limit the need for active air conditioning.

At Rout Lëns, solar protection, green roofs, trees, vegetation, emerging roofs and insulation are some of the many solutions planned to minimize the district’s energy needs.


Anything to make future generations thank us…

The design of a new district is a process that is envisaged over the very long term, on the scale of several generations!

Rout Lëns has to respond to all the issues currently identified, but also to be evolutive in order to face future new constraints, foreseeable or unexpected.

Thanks to the architectural and urbanistic conception as well as to the innovative energy mix, we are doing everything possible to make Rout Lëns a district resolutely turned towards a better future.

Together, we are building a new living space where each generation can flourish in harmony with its environment!