Oikodomisis

Construction-Site Power: How the Initial Connection Works and How It Is Converted to a Permanent Supply

The construction of a new building or the radical renovation of an old property is an exciting, but also bureaucratically exhausting journey. Before the first concrete is even dropped or digging begins, your craftsmen (builders, blacksmiths, electricians) need electricity to operate their tools.

But how do you get electricity for a house that... doesn't exist yet?

This is where construction-site power comes in. It is a temporary supply that HEDNO provides exclusively for building works. The process has two distinct phases: the initial temporary connection at the start of the project, and the final conversion to a permanent supply once the property is ready.

1. What Construction-Site Power Is and What the "Pillar" Means

Unlike a finished domestic installation, construction-site power is temporary, exposed, and designed to serve works in progress.

Illustration for 1. What is the Workplace Stream and the "Pillar" (Pillar)

The Installation

Your electrician places a special, waterproof metal box, called a Pillar, at the edge of the plot. This box contains the HEDNO meter, the main switch, the leakage relay (absolutely necessary for construction accidents) and some industrial sockets that contractors plug machines into (eg concrete mixers, electric welders).

The Charge

Construction-site power does not use a low domestic tariff. It is usually billed under a professional tariff because it is treated as a working supply, so it is not economical to keep it any longer than necessary.

2. Phase 1: The Initial Connection (Starting the Tasks)

Illustration for 2. Phase 1: The Initial Connection (Starting the Tasks)

In order for HEDNO to give you this temporary provision, you must prove that you have the legal right to build. The process is now mainly done through the digital portal of HEDNO, and the supporting documents are strict:

  1. The Building Permit (The Most Important): You must have the Building Permit from the e-Permits system, which has a special "Stamp for Site Power Supply" from the competent Building Service (YDOM/Urban Planning).
  2. YDE (Electrician's Plan) for the Site: Your licensed electrician must issue a Certificate (YDE) ​​which does not concern the future house, but exclusively the safety of the temporary Pillar he set up on the plot.
  3. Title Deeds: Contract of the plot or building.
  4. Proof of VAT number & Identity of the owner or legal representative.

The duration of the construction-site supply is tied to the validity of the building permit. If the permit expires, HEDNO can disconnect the supply unless your engineer has already secured an extension.

3. The Risk: Can You Live with Construction-Site Power?

This is the most common mistake (and often a violation) in Greece. The house is being finished internally, the furniture is in, the owners are moving in, but they have not yet received the Final Seal from the Town Planning Office. Thus, they connect the house board to the construction site Pillar.

Why it is strictly prohibited:

  1. Safety issue: the site YDE only covered the temporary pillar outside, not the finished indoor installation. If something goes wrong inside the house, you are not properly covered.
  2. High Cost: You pay for electricity very expensively (business tariff) without the right to Social Tariff (COT) or heating allowances.
  3. Fines: HEDNO carries out checks. If it is found that construction-site power is used for domestic use (illegal change of use), heavy fines and interruption of supply follow.
Illustration for 3. The Risk: Can I live with Industrial Current?

4. Phase 2: The Final Conversion (Normal Current)

Illustration for 4. Phase 2: The Final Conversion (Normal Current)

Once the house is finished and ready for lawful occupation, the temporary construction-site supply must be converted into the permanent residential or commercial connection.

This is the most bureaucratic part, as it requires the involvement of three different professionals (Civil Engineer, Electrician and Accountant):

  1. Seal of Final Supply (Urban Planning): Your Civil Engineer must close the building file. He will call in a Building Inspector, who will confirm that the building was built exactly as the permit plans said (no tampering). Then, YDOM issues the Final Connection document.
  2. New YDE (Electrical Plan) for a Home: Your electrician issues the final, complete certificate that we analyzed in a previous article, which now captures the internal panels, sockets and final earthings of the house.
  3. TAP Certificate (Real Estate Tax): Issued by your Municipality. It proves that the declared square footage of the building is identical to that of the license, so that the Municipal Fees can be charged correctly through the electricity bill.
  4. EFKA Payment Proof (formerly IKA): For new buildings, a certificate from EFKA is required that all the workers' fees that worked on the project have been paid. If you owe stamps, you don't get electricity.

The Necessary Documents for Permanent Connection:

5. The Removal of the Pillar

Once all documents have been submitted to HEDNO and approved, you sign the final supply contract with your chosen provider. HEDNO then removes the temporary pillar and installs the permanent utility meter in its final approved position on the boundary or facade.

Summarizing

Construction-site power is the temporary energy supply that allows a building project to take shape. Managing it properly requires coordination between the civil engineer handling the permit side and the electrician handling the installation and HEDNO requirements. If the paperwork and inspections are closed on time, the transition to permanent supply is straightforward.

Next Step: We've seen how a new building is powered. But when the electrician makes the installation of this new building, he does not follow the rules of the 90s.

We continue with the guide for the new technical specifications imposed by the law: The New Standard ELOT 60364 (formerly KEHE & HD384): What has changed in the legislation of internal electrical installations (For Engineers & Electricians).

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What Is an Electrician's Certificate (YDE): When It Is Mandatory, What It Includes, and Why HEDNO Requires It Changing the Electricity Account Holder: Which Documents You Need and When a New YDE Certificate Is Required The New ELOT 60364 Standard (formerly KEHE and HD384): What Changed in Internal Electrical Installation Rules Night Tariff (HEDNO): How to Apply, What Changes at Your Meter, and the 2026 Time Windows

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