Oikodomisis

Power Extension (DEDDIE): The process, supporting documents and costs step by step (Guide 2026)

You've found, as we've discussed in previous chapters, that your old panel can't handle your brand new heat pump or electric car charger. You urgently need more current (either more single-phase, or switching to three-phase).

The first mistake many people make is to call their provider (eg PPC, Protergia, Heron) and ask for "higher current". The provider does not bring the cables! DEDDIE (Hellenic Electricity Distribution Network Operator) is solely responsible for the network, meters and capacity.

The Power Up process has been largely digitized, but remains a serious bureaucratic and technical path. As engineers, we've prepared a practical, step-by-step guide to what to do, how much you'll pay and how long you'll wait in 2026.

Step 1: The visit of the Electrician (The Certificate)

DEDDIE is not going to give you more power (or change your meter) if you don't prove to them that your indoor installation can handle it safely.

Illustration for Step 1: The visit of the Electrician (The Certificate)

The first step is to call your own licensed electrician.

The first step is to call your own licensed electrician.

The electrician will upgrade your panel and the main supply cable (if required).

The electrician will upgrade your panel and the main supply cable (if required).

Then, he will take measurements and issue you a new Installer's Responsible Declaration (YDE), the well-known "electrician's paper". The new requested power (eg 25 kVA for three-phase) will be explicitly written on the YDE. Without this paper, the application does not start.

Then, he will take measurements and issue you a new Installer's Responsible Declaration (YDE), the well-known "electrician's paper". The new requested power (eg 25 kVA for three-phase) will be explicitly written on the YDE. Without this paper, the application does not start.

Step 2: The Application to DEDDIE (Digitally)

Illustration for Step 2: The Application to DEDDIE (Digitally)

Now you don't have to queue up at local agencies. The application is made through the digital service portal of DEDDIE (apps.deddie.gr), entering with the TaxisNet codes.

The Basic Documents you will need to upload (in PDF) are: 1. Copy of Police ID (or Passport). 2. Proof of VAT (a printout from myAADE or a bill of sale). 3. New Responsible Installer Declaration (YDE): Which, in fact, is now digitally registered in the register by the electrician himself. 4. Title Deed or Lease: If you rent, the platform often requests the electronic lease from TaxisNet to confirm legal use, while in some cases a responsible statement of consent from the owner is also required. 5. A recent electricity bill: To identify the Supply Number.

Step 3: The "Financial Offer" and Payment

After your file is reviewed, DEDDIE will send technicians for an autopsy on your watch (if the increase is large). They will calculate whether the street cable can withstand the new load or if they have to dig. They will then email you the Financial Offer (Connection Fees).

How much does it cost? (Calculation 2026) The cost of the increase is NOT fixed, but is calculated based on the kVA (Kilovoltamber) you request in addition to what you already have.

If you agree, you pay the amount with payment code (RF) through e-banking. This practically constitutes the signing of the Connection Agreement.

Illustration for Step 3: The "Financial Offer" and Payment

Small Increase (Single Phase 8 kVA to 12 kVA)

It usually only includes the inspection fees and power difference. Cost around €60 - €120.

Switch to Three Phase (Single Phase 8 kVA to Three Phase 25 kVA)

Here you pay the difference of 17 kVA (at a cost factor per kVA) plus the cost of the new, three-phase meter. The standard cost sent by DEDDIE for a simple clock change without network extension varies between €300 and €500.

Attention

If your house is in an isolated spot and DEDDIE has to put a new pole or dig whole meters in the street to bring a thicker cable, the offer can exceed €1,000.

Step 4: The Technical Implementation (The Meter Change)

Illustration for Step 4: The Technical Implementation (The Meter Change)

As soon as the payment is "shown" in the DEDDIE system, the case goes to the construction department. A DEDDIE contractor's workshop will come to your home. The process is quick: They cut the power. They remove the old meter. They install the new, digital smart meter (Smart Meter). They connect it to your new mains cable (which your electrician has already left ready for you).

Step 5: Notifying the Provider (Supply Agreement)

Once DEDDIE has finished the job and the new clock starts ticking, the process is not bureaucratically over.

You must call the company that sells you electricity (the Provider) and inform them that your supply has become three-phase (or that the power has increased). You will need to sign a new Supply Agreement as the charges for the regulated fees are now changing (you pay a higher fixed fee for using the network).

If you do not do this in time, there may be a problem with the issuance of your bills, as the provider's system will not match the DEDDIE information.

Timeline: How long will I have to wait?

This is the most common source of irritation for consumers. Although the processes were digitized, the implementation times depend on the workload of the local DEDDIE agency.

Engineer's Advice: Never order the Heat Pump or the Car if you do not have the DEDDIE paid offer in hand. Start the application at least three months before you plan to make your big device purchase.

Next Step: Many owners ask: "I don't want to mess with DEDDIE and add-ons. If I buy an electric car and plug it into my simple, single-phase outlet, what will happen?" Continue to the next article to demystify home electrification: Can a Single-Phase Home Sustain an Electric Car? What is true in practice?

Ideal Scenario (Simple Urban Areas)

It takes 10 - 20 days from the day of the application until you receive the offer. From the day you pay until they come to set the clock, count another 15 - 30 days. Total: about 1 to 1.5 months.

Bad Scenario (Network Projects Required)

If DEDDIE has to dig, close roads, get permission from the Municipality or erect pillars, the wait can easily last from 3 to 6 months.

Related Articles

Single-Phase or Three-Phase Current? The ultimate guide to choosing what your home needs When to Upgrade to Three-Phase Supply: Heat Pumps, Wallboxes and "heavy" consumptions Can a Single Phase Home Sustain an Electric Car? What is true in practice? Downgrading from Three-Phase to Single-Phase: When it's worth doing it to save fixed costs (and when it's forbidden)

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