How to best replace walk-by meter reading

A technician with a laptop and an antenna walks the corridors of an apartment building once or twice a year to catch signals from water and heat meters. That is what walk-by meter reading still looks like in most residential buildings today. When a meter cannot be captured due to shielding, distance, or interference, the technician tries another spot in the corridor, or in the worst case, has to return another day. The result is one or two data points a year, which no longer meets today's expectations.

What is walk-by meter reading?

Walk-by is one of three classic categories of automated meter reading (AMR). Alongside walk-by, there is drive-by, where data is captured by a receiver in a passing vehicle, and fixed network, where receiving infrastructure is permanently installed in the building. Walk-by and drive-by systems have been in use since the 1980s as the first alternative to manual on-site meter reading, and they still operate in a large share of residential buildings today.

Importantly, all three categories, walk-by, drive-by, and fixed network, remain AMR. The meter itself stays the same; only the way its data is collected changes. This differs from AMI (advanced metering infrastructure), which involves installing a new smart meter in place of the existing one. Moving from walk-by to fixed network is therefore a fundamentally different, and cheaper, change than moving to AMI.

The Energy Efficiency Directive (EED) is pushing for more frequent consumption data. It is no longer just about annual billing; it is about an ongoing overview that can flag unusual consumption or a water leak early. EU member states are required to introduce remote meter reading by 2027, which is why building administrators are looking for ways to replace walk-by reading with a fixed network solution. Some assumptions about EED obligations no longer hold. In practice, three approaches are most commonly considered.

Wiring everything to a single point

Meters are connected by cable to a central point in the building, where a concentrator with an internet connection is installed.

• Data transmission is stable, and the building administrator keeps full control.
• Installation in already completed buildings tends to be more complex and expensive.
• Cable routes and work in shared areas need to be planned carefully.

‍

Whether cabling or a battery-powered wireless solution truly pays off depends on more factors than it first appears.

Switching to meters with direct LoRaWAN communication

Meters send data directly to a LoRaWAN network, which then forwards it to the administrator's system.

• Installation is fast, with no need to build in-building infrastructure.
• This tends to suit new installations or a planned meter replacement.
• If a building already has functioning wM-Bus meters installed, moving to LoRaWAN means replacing them, even where they still have a valid calibration.
• Operational demands shift to the network infrastructure: this depends on gateway availability, connectivity, and the service provider.

wM-Bus concentrator: replacing walk-by without replacing meters

The third path is a wM-Bus concentrator, moving straight from walk-by to fixed network without changing the meters.

The principle is simple: meters in individual flats keep transmitting exactly as before (wM-Bus), but the building has a permanently installed concentrator that continuously receives the signal, gathers the readings, and sends them over the internet to the administrator's or billing provider's system. The technician's job is not replaced by a better antenna, but by a device permanently present in the building. Advantages of this approach:

• Existing wM-Bus meters continue to be read, so there is no need to replace them to change the reading method.
• Meters can run to the end of their calibration period, and replacement happens naturally and gradually.
• The wM-Bus standard tends to offer a wider range of meters from different manufacturers, making it easier, and often cheaper, to choose a suitable type than with a narrower LoRaWAN portfolio.
• The solution works automatically, but leaves a fallback open: if anything happens to the internet connection or the concentrator, it remains possible, as a last resort, to visit the building with a laptop and antenna and take a walk-by reading, as before.

Comparing the three approaches

There is no single universally best solution. The right choice depends mainly on what meters are currently installed in the building, how long they will remain in service, and what the administrator is trying to achieve.

In many retrofit projects, though, it makes the most sense to keep functioning meters and modernise only the reading method, moving from walk-by to fixed network with a wM-Bus concentrator, without having to discard working meters or give up walk-by entirely as a fallback.

If you are not sure whether your existing meters are suitable for this step, we cover the topic in more depth in Can your existing meters be retrofitted for remote reading?

‍

Glossary of terms used

• ‍EED (Energy Efficiency Directive) – the EU directive on energy efficiency, which among other things sets requirements for remotely readable meters and regular access to consumption data.‍
• Walk-by meter reading – a reading method in which a technician regularly visits the building with a receiver to collect data from meters communicating wirelessly. One of three AMR categories, alongside drive-by and fixed network.‍
• AMR (Automated Meter Reading) and AMI (Advanced Metering Infrastructure) – AMR is the automated collection of data from an existing meter without replacing it. AMI requires installing a new smart meter in place of the existing one.‍
• Wireless M-Bus (wM-Bus) – a wireless communication standard used to transmit data from water meters, heat meters, and other meters, widely used in residential buildings.‍
• OMS (Open Metering System) – an open, vendor-independent standard built on wM-Bus, ensuring interoperability between meters from different manufacturers.‍
• Concentrator – a permanently installed unit that continuously receives data from meters in a building and forwards it over the internet to a central system.