If you are planning submetering, the biggest determinant of complexity is whether the building is new construction or an existing retrofit. New builds can be designed for metering from day one. Retrofits have to work around what is already in the walls, panels, and risers.
In new buildings, submetering can be incorporated into suite electrical layout, dedicated meter rooms or cabinets sized for metering equipment, and communications pathways and network design. Clear access to feeders and panels, space and pathways planned for metering hardware, and fewer surprises with legacy wiring make new construction simpler.
Retrofit projects are highly doable, but they require an honest feasibility review. Electrical architecture varies widely, access constraints exist, space constraints are real, and legacy wiring and panel condition can present issues.
Most retrofits end up in one of three patterns: centralized metering (meter room or electrical rooms), floor-by-floor metering, or suite panel metering. Modern systems often reduce wiring complexity using communications modules and wireless or low-power networks.
A retrofit often has three phases: survey and design, install and commissioning, then billing go-live. Building size, access windows, and electrical complexity drive the schedule more than anything else.
The cleanest projects usually do not rush the mapping and commissioning phase. Incorrect mapping causes billing issues, and billing issues create resident friction.
New builds win on predictability. If designed properly, submetering becomes part of the building's normal operations. Retrofits win on impact. They upgrade an older building, improve billing fairness, and can materially change operating expenses and resident behavior.