As a client representative I have experienced construction projects from the other side of the table. One insight has shaped me in particular:
Most variations in electrical engineering do not arise on site. They arise months earlier. In a meeting where nobody asked how many workplaces the building should have in five years. In a room data sheet that was never finished. In an interface nobody thought was theirs.
In many buildings, electrical engineering accounts for a substantial share of construction cost. Under DIN 276 that is mainly cost groups 440 (electrical systems) and 450 (communication, safety and information technology systems). And few trades have as many interfaces.
In this article I show at which points in the HOAI work stages (the German fee scale for architects and engineers) it is decided whether a project stays on budget — from the perspective of an engineer who has installed systems himself, designed them and supervised them as client representative.
Point 1: Basic evaluation (LPH 1) – clarify needs honestly
What should the building be able to do — today and in ten years?
The question sounds banal. In practice it is often answered too quickly. Yet it decides connection capacity, distribution structure and cable routes. A heat pump that comes later. Charging points for the fleet. A server room that is meant to grow. All of that has to be on the table in basic evaluation.
My tip: Do not only ask for needs — have them confirmed in writing. An agreed room data sheet is the best insurance against later changes.
Point 2: Preliminary and design development (LPH 2 and 3) – set the big switches
In preliminary design and design development the decisions fall that can barely be changed later: location of plant rooms, routes for cables and services, grid connection, emergency power supply, emergency lighting, fire detection system.
At the same time the cost calculation to DIN 276 takes shape. Anyone working with blanket figures here is painting the project pretty. A robust cost calculation for cost groups 440 and 450 needs a thought-through system concept.
My tip: Coordinate plant areas with the architect early. An electrical room that is too small cannot be rescued in detailed design.
Point 3: Approval and detailed design (LPH 4 and 5) – close the interfaces
Detailed design is the phase of detail. This is where it shows whether the trades fit together. Who supplies the ventilation plant? Who provides the control cable to the fire damper? Who connects the lifts?
These questions sound small. Unanswered they grow large. A gap in the interface list becomes a variation on site.
Modern design tools help. With Revit and a shared building model (BIM), collisions between trades can be spotted early. But even the best model does not replace the experience of how a route is actually installed on site.
My tip: An interface list with clear responsibilities is not bureaucracy. It is one of the most effective tools against variations.
Point 4: Tendering (LPH 6 and 7) – the bill of quantities decides
A bill of quantities is only as good as the design behind it. Missing items, unclear quantities or open manufacturer questions almost inevitably lead to variations.
From the client’s perspective a second look before issue therefore pays off. Does the bill of quantities match the cost calculation? Are all interfaces covered? Is initial verification to DIN VDE 0100-600 with documentation part of the scope?
My tip: Do not limit tender review to price alone. Conspicuously low unit rates are often a hint of later variations.
Point 5: Site supervision (LPH 8) – look closely
In site supervision, design meets reality. This is where it is decided whether the installation is built as designed.
Good site supervision means: be on site regularly, name defects early and document cleanly — especially for work that later disappears behind ceilings and in walls: firestopping, cable installation, equipotential bonding.
Practical experience helps here. Anyone who has installed themselves knows where shortcuts are tempting on site — and where to look more carefully as a result.
Point 6: Post-completion (LPH 9) – close the project properly
After handover comes operation. In post-completion services, defects during the warranty period are chased. And it becomes clear whether the documentation is fit for purpose: as-built drawings, test reports, operating manuals.
Incomplete documentation is a silent cost driver. It makes every maintenance visit, every fault hunt and every alteration more expensive.
What clients can take from this
Electrical design is not a trade you “bolt on” late in the project. It influences areas, routes, cost and programme from the start. Three questions help gauge the quality of an electrical design:
- Were needs agreed in writing in LPH 1?
- Is there a complete interface list with clear responsibilities?
- Is the cost calculation for cost groups 440 and 450 derived from a system concept, or from blanket figures?
If any of those answers is uncertain, a closer look is worthwhile.
Conclusion
Good electrical design does not show in pretty drawings. It shows in few open questions remaining on site — and in the client ending up with a building that is on budget and works in operation.
I know construction projects from execution, from design and from the client’s side. That combination is what I bring into every work stage.
Facing a construction project and looking for an electrical project engineer for building services (MEP) who connects design and the client’s perspective? Let’s talk.
Note: This article gives an overview and does not replace advice on a specific case.