Separate connections or a collective assessment?

Charging in an apartment block: two routes

Chargers can be introduced in a multi-family building in two ways. The first is separate connections or circuits for individual residents, each with its own documentation. The second is one collective assessment and design for the whole building, with an installation prepared for the target number of points and a system that shares the available power between cars. The difference in cost and convenience can be huge.

Drawbacks of individual connections

The “one point at a time” approach looks simple, but at building scale it quickly backfires:

• Formalities and costs multiply — each installation means a separate assessment, design and approvals, often with different contractors.
• Power runs out fast — rigidly reserving power for each point means the next residents are told there is “no connection capacity left”, even though the chargers never all run at once.
• No coordination — different standards, different hardware and messy documentation make servicing and fire-safety/UDT acceptance harder.
• Unequal access — “first come, first served”; adding more points later is more expensive and more difficult.
• Risk of overloads — several cars charging at the same time on a rigid power allocation strain the building’s installation.

Advantages of a collective assessment and design

• Lower unit cost — one assessment and design for the whole building; the more points, the cheaper each one.
• Planned headroom and phased expansion — the installation is prepared for the target number of chargers, and devices are added as needed.
• One standard and order — one contractor, consistent documentation and acceptance (including fire safety/UDT) with no rework along the way.
• Easy addition of further points without repeating the whole procedure.
• One billing system per user, with no commission on energy sales — the association doesn’t pay for anyone else’s charging.

DLB: dynamic load balancing

Dynamic load balancing (DLB) is at the heart of the collective solution. Instead of reserving full power for each charger, the system shares the available power between the points that are actually charging at any given moment. When one car is charging, it gets more; when several are — the power is split between them without exceeding the installation limit.

As a result, the same connection can support many times more points than with a rigid allocation, without costly increases to the building’s connection capacity. More advanced versions also take into account the current consumption of the whole building (lifts, lighting in common areas) and protect the installation from overload at peak times.

The scope of requirements (including power headroom and fire safety) depends on the specific building. We confirm it after analysing the installation.

What it gives the housing community

A collective assessment with DLB means more chargers on the existing connection, a lower cost per point, orderly formalities and a safe installation — while each resident still pays only for their own sessions. At Domena Power, we run such a project end to end: from the collective assessment and design, through installation and DLB, to a commission-free billing system.