L'énergie verte au cœur de Rout Lëns
by routlens

Green energy at the heart of the Rout Lëns neighbourhood

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 in our lifestyles, the way we live, eat, work, build and even move.

Against this backdrop, from the very first sketches, it was vital that sustainability should be right at the heart of the Rout Lëns project.

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

Our ambition: to make a commitment to become carbon neutral!

When it comes to energy, you have to take things seriously. Our goal is to use as little fossil fuel as possible, in order to reduce CO2 emissions across the neighbourhood.

To achieve this, we have designed a unique combination of clean energy solutions. This combination will supply electricity and heat without using gas or oil!

As well as this, as the architectural and urban planning have been designed to minimise the demand for energy from the outset, this neighbourhood will consume less than a traditional one.

Rout Lëns, un quartier 100% neutre

Rout Lëns, a neutral neighbourhood.

The optimal energy mix

Finding the best possible energy mix was no mean feat. That’s why the neighbourhood underwent a detailed conceptual energy study. This meant that we could put together a strategy that would fit in perfectly with the specific features of the site, as well as complying with legal obligations.

The energy strategy we adopted is a bottom-up approach. So it is based primarily on limiting energy demand and then choosing green technologies adapted to the remaining requirements. Residents and users will thus be able to enjoy maximum comfort while limiting their environmental impact.

The expected distribution is as follows:

For electricity:

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

For heat:

  • Air/water heat pump: 40%
  • Geothermal heat pump: 40%
  • Waste water heat recovery: 10%
  • Centralised wood-fired heating system: 10% (This is the only one that emits CO2. It will cover times when the demand for heating is as its peak)

Innovative technologies for a forward-thinking neighbourhood

Some of the energy solutions planned for Rout Lëns deserve a bit of our attention.

BIPV, or when the windows produce electricity:

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

Particularly well-suited to urban areas, BIPV gives you the chance to make the most of the enormous potential offered by the facades of office and apartment buildings. It complements the electricity produced by traditional photovoltaic panels on the roof.

These innovative new materials are particularly attractive, and give architects the chance to express their creativity while promoting renewable energy.


An urban network with 2 types of heat pump:

After the sun, the air and ground provide us with two particularly appealing and infinite sources of green energy. Air-water and geothermal heat pumps will be installed to harness this energy.

Air-water heat pumps draw calories from the outside air and diver them into a building’s heating system. Geothermal heat pumps use energy from the earth’s subsoil where the temperature remains relatively stable throughout the year. One particular feature, and the strength of the Rout Lëns geothermal network, lies in the use of 5 underground car parks. These will be used for the network of “basket” probes, which will be fitted at a medium depth.

In addition to state-of-the-art technology, heat will be supplied via a centralised urban heating network. This will mainly provide heating for domestic water, as the buildings are insulated so well that they are designed to be passive.

This network that runs through the whole neighbourhood offers a two-fold advantage. First of all, it means that costs, such as those associated with maintenance, are spread out. Secondly, it streamlines consumption according to the timetables and needs of the different activities (offices, shops, homes etc.).

Recovering heat from waste water:

In Rout Lëns, nothing will be left to chance when it comes to producing heat at source! Did you know that when you take a shower at 40°, the water that trickles away is still 35°?

By recovering the residual heat from this water and sending it back into the water heating system, a considerable amount of heat energy can be reused.

In our new neighbourhood, it is estimated that this instant heat recovered from waste water will contribute 10%.

Ressources, techniques et architecture propres au projet Rout Lëns

Resources, techniques and architecture specific to the Rout Lëns project

Limiting energy needs from the outset

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

It is now known that architectural and urban planning choices have a major impact on the energy performance of buildings and the neighbourhood. They have a fundamental impact on heating and electricity needs. For example, access to natural light avoids the inopportune use of artificial lighting. Areas with a lot of plants or shade reduce the need for active cooling.

In Rout Lëns, sun protection, green roofs, trees, plants, raised rooftops and insulation are just some of the many measures planned to minimise the neighbourhood’s energy needs.

Future generations will be grateful for all of this…

Designing a new neighbourhood is a long-term process, spanning several generations!

Rout Lëns must respond to all the issues that have already been identified, but also be scalable to meet new restrictions in the future, whether or not they can be anticipated.

Thanks to the architectural and urban design and the innovative energy mix, we are doing everything possible to make Rout Lëns a neighbourhood that is resolutely looking towards a better future.

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

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