There is a decision that almost every developer and architect gets wrong at least once in their career: leaving the electrical engineer until later. The logic seems reasonable at first glance — finish the architectural design, then bring in the electrician to place outlets and light fixtures. This mindset carries a serious price: budget overruns, licensing delays, floor plan redesigns, and in extreme cases, demolition of already-constructed masonry.
This article covers exactly when the electrical engineer must enter the building design process, what role they play at each stage, and — most importantly — what the real cost looks like when that decision is delayed.
The 4 Design Phases — and Where the Electrical Engineer Fits
Phase 1: Concept Design (Pre-Design)
The concept design stage is where the building's use, spatial layout, general functions, and permitting requirements are defined. Most teams do not involve the electrical engineer here. That is a mistake.
What must happen in Phase 1:
- Initial electrical load calculation based on building use (residential, office, hotel, industrial)
- Determination of whether a private substation is required or whether connection from the public grid is sufficient
- Check whether the local grid infrastructure can support the required power demand
- Initial location of the Main Distribution Board (MDB) and telecommunications rooms
If the electrical engineer is absent from this phase, the architect designs a building without knowing whether the available infrastructure space is adequate. The result: redesign of central nodes or, in the worst case, inability to connect to the grid without significant additional cost.
Phase 2: Architectural Design (Schematic / Design Development)
This is the phase where the presence of the electrical engineer is absolutely critical. Phase 2 defines floor plans, ceiling heights, wall positions, and openings — all of which directly affect cable routing, panel placement, and signal system infrastructure.
What must happen in Phase 2:
- Preliminary electrical floor plan drawings and single-line diagrams
- Definition of conduit routes for power and signal systems
- Allocation of spaces for distribution panels, UPS, and generator (where required)
- Coordination with the mechanical engineer for HVAC, elevator, and pump room requirements
- Initial energy consumption estimates for the Energy Performance Certificate
Without this coordinated presence, cables end up with nowhere to go, suspended ceilings are undersized, and panels get relocated to storage rooms or stairwells with inadequate access.
Phase 3: Construction Documents
At the construction documents stage, the electrical engineer produces the detailed electrical study required for permitting and construction:
- Full electrical floor plan drawings
- Panel single-line diagrams
- Material technical specifications
- Load calculations, short-circuit calculations, and voltage drop analyses
- Lightning protection and earthing/grounding design
Phase 4: Construction and Site Supervision
During construction, the electrical engineer supervises the installation of systems, checks compliance with specifications under ELOT EN 60364, and issues the Installer's Declaration of Responsibility required for connection to the public grid.
What It Costs When the Electrical Engineer Joins Late: Real Scenarios
Scenario 1: The Panel That Does Not Fit
A four-storey office building. Architectural design complete. Construction documents at 70%. The electrical engineer is called in for the first time. They find that the space allocated for the Main Distribution Board is inadequate for the equipment required by the building's power demand. Redesign of the space, modification of structural elements, permitting delay of six weeks. Estimated additional cost: 8,000 to 15,000 euros.
Scenario 2: The Suspended Ceilings That Should Have Been 20cm Higher
An 80-room hotel. During installation of electrical infrastructure, it is discovered that the suspended ceiling void is not deep enough to route both power and signal cables simultaneously. The solution: reduce the net floor-to-ceiling height by 15cm across three floors, or reconstruct part of the ceiling structure. Remediation cost: 22,000 to 35,000 euros. Delivery delay: three weeks.
Scenario 3: The Connection That Was Never Planned
An industrial facility. The developer does not involve an electrical engineer in the concept design phase. The required installation capacity (750kVA) cannot be supplied by the existing aerial service connection. A private medium-voltage substation is required. Implementation timeline: five to eight months. Additional cost: 80,000 to 120,000 euros. The project restarts from the concept design phase.
Why Developers Leave the Electrical Engineer Until Later
"We want to minimise study costs in the early phases" — In fact, early involvement costs less because changes on paper are far cheaper than changes on site.
"We do not know the final uses yet" — Even with uncertainty, the electrical engineer can model a range of loads and design scalable infrastructure.
"We will sort it out on site" — This is the most expensive possible approach. An active construction site means change costs five to ten times higher than changes made during the design phase.
Frequently Asked Questions
Ideally from Phase 1 (Concept Design) for load calculations and grid capacity checks. Mandatory from Phase 2 (Architectural Design) for coordination of floor plans, conduit routes, and equipment rooms. Later than this already means revision costs.
For a medium-sized residential property (150 to 250 sq m), an electrical study typically ranges from 800 to 2,000 euros. For a commercial building or industrial facility, the study can reach 5,000 to 30,000 euros or more. In every case, the cost of the study is a fraction of the cost caused by late-stage design.
Formally, responsibility is distributed between the architect and the electrical engineer according to contract. In practice, when there is no explicit coordination agreement, remediation costs fall on the contractor or the developer. This is why the design contract must clearly define who coordinates the individual study components.
On most projects, the electrical engineer handles both, or collaborates with a specialist weak current consultant. On large or specialised buildings such as hospitals, data centres, and hotels, role separation is standard practice and is recommended.
Yes. Site supervision is required both for safety and for the issuance of the Installer's Declaration of Responsibility, which certifies compliance with ELOT EN 60364. Without it, connection to the public electricity grid cannot proceed.
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