Construction power (Dutch: bouwstroom) is the temporary electrical supply provided to a building site before the permanent mains connection is installed. It allows contractors to run power tools, lighting, site cabins, and other equipment from the very first day of construction.
How construction power works
A temporary connection is requested from the regional grid operator or energy supplier. Once approved, a site distribution board (also called a building site switchboard) is placed at the entrance of the site. This board distributes electricity to various circuits across the work area and includes built-in safety features such as residual current devices (RCDs) and circuit breakers.
The distribution board typically provides both single-phase (230 V) and three-phase (400 V) outlets. Three-phase power is essential for heavy equipment like cranes, concrete mixers, and large compressors, while single-phase outlets serve hand tools and lighting.
Safety requirements
Construction power installations must comply with national electrical regulations. Key requirements include:
- The distribution board must be weatherproof (minimum IP44 rating).
- All circuits must be protected by RCDs with a maximum trip current of 30 mA.
- Cables routed across the site need mechanical protection or must be elevated above ground.
- Regular inspection by a qualified electrician is mandatory, typically before first use and at set intervals throughout the project.
Application in construction
Construction power is one of the first services arranged when a building project begins. Without it, virtually no modern construction activity can take place. The temporary connection remains active until the permanent electrical installation is commissioned and the building is connected to the grid. At that point, the site distribution board is removed and the temporary contract is terminated.
On larger projects, multiple distribution boards may be placed at different locations across the site to reduce cable runs and voltage drop.
Related terms
Want to learn more about construction terms? Visit the knowledge base at Fred’s DIY Plans.