My name is Giannis, and my story begins long before I earned my degree in Civil Engineering. It begins on the rugged slopes of Epirus, standing beside my grandfather—the original “Mastro-Giannis.”
In Epirus, a land world-renowned for its master stonemasons, my grandfather wasn’t just a builder; he was a Maistor (from the medieval Greek Maistor and the Latin Magister). This title was reserved for the master craftsman, the teacher, and the chief of works. The summers I spent by his side were my first true “construction sites.” There, amidst the scent of dry stone and the rhythmic strike of the hammer, he taught me that building something to last forever requires more than just blueprints—it requires soul and a deep, tactile understanding of your materials.
The surname Mastrogiannis is a fusion of this history:
Today, as a Civil Engineer, I carry both his name and his legacy. For me, “Mastrogiannis” is not just a surname; it is a promise. It is the point where scientific precision meets the authentic mastery of the past. It is my way of honoring the man who taught me that being a “Mastro” is the highest title of honor any creator can achieve.
For simplicity, you may simply call me Master Giannis.
I am Mastrogiannis, and first and foremost, I am a Civil Engineer. My world isn’t made of sales pitches; it is made of structural calculations, building permits, and the laws of physics. For 20 years, I’ve been on the front lines of the Greek construction site. I’ve seen that in real estate, everyone has an opinion, but only a Civil Engineer has the responsibility. I created o-mastrogiannis.gr to place the Engineer exactly where he belongs: at the heart of every property decision.
In a market flooded with “experts” and “advisors” who only know how to talk, I built a digital fortress of technical truth. This platform exists to bridge the gap between complex Greek bureaucracy and the person who needs a straight answer. From our Construction Cost Calculator to our Structural Audits, everything we do is guided by engineering science. We don’t guess; we calculate. We don’t “think”; we verify.
We are not for the “know-it-alls” or those who rely on hearsay and rumors. O Mastrogiannis is for those who choose to listen. We are for the people who respect expertise and understand that in a foreign or complex market, the most expensive thing you can buy is a “cheap” or “uninformed” opinion. We are for the investors and homeowners who want to sleep soundly at night, knowing that a Civil Engineer has put his signature on the technical integrity of their asset.
Whether you are an Athenian family planning your first renovation or a global investor looking for a €800,000 asset, our philosophy remains the same:
Buying or building in Greece shouldn’t be a gamble. It should be a calculated move. I am Mastrogiannis, and as a Civil Engineer, I don’t just find you a property. I engineer the security of your investment.
Most agents show you what they have in their “drawer.” I do the opposite. I work for you, not the seller.
Best for: Investors seeking Passive Income or Fix-and-Flip opportunities.
We don’t just find properties; we engineer returns. Whether you need us to source an undervalued asset or validate one you have already identified, we ensure your capital is backed by structural integrity and high ROI.
Real estate investing in Greece requires more than a simple search. It requires the ability to see the hidden potential and the hidden risks. The Investment Key service provides a 360° technical approach to asset acquisition.
For investors looking for the right opportunity.
For investors who have already identified a property.
Most advisors in the market are commission-driven. We are Engineer-driven.
Independent Engineering Supervision for owners who demand technical excellence and financial integrity. From the heart of Athens to the villas of the Aegean, we are your Professional Oversight on the ground.
Construction in a foreign country can be a complex and risky endeavor. The biggest risk is not the construction itself, but the lack of independent technical supervision. Hiring a contractor without an independent Civil Engineer to oversee the quality and the costs often leads to technical compromises and budget overruns.
“The Engineering Oversight” provides a comprehensive shield. We do not just “watch” the work; we enforce standards, certify materials, and manage every milestone of your project.
| Pillar | How We Protect Your Investment |
| Nationwide Operations | Our expertise spans all of Greece. Whether you are developing a luxury villa in the Cyclades, a boutique hotel in the Peloponnese, or a modern apartment in Thessaloniki, we provide consistent, high-level technical management. |
| Material & Systems Certification | We implement a rigorous quality control protocol. Every component—from structural steel and concrete to electrical wiring and plumbing systems—is inspected and verified against European standards before installation. |
| Milestone-Based Fiscal Control | We eliminate financial uncertainty. We establish a strict “Pay-as-you-Build” schedule. Contractors are paid only after our lead Engineer certifies that the specific stage is completed to perfection. |
| Total Remote Transparency | Distance is no longer a barrier. You receive weekly Engineering Progress Reports featuring high-definition video, technical checklists, and photo documentation of everything “behind the walls” before it is covered. |
We focus on the critical technical details that determine the longevity and safety of your asset:
If you have an ongoing project in Greece that is facing delays, technical disputes, or quality concerns, we offer a Technical Recovery Audit. We step in, assess the current status, and provide a roadmap to bring the project back to professional standards and completion.
“I am not just a project manager; I am your Technical Governor. My mission is to ensure that your investment in Greece is built with scientific precision and total transparency. I am your eyes, your ears, and your scientific voice—anywhere in Greece.”
In a market full of “sales pitches,” I offer Technical Truth. Here is why my involvement is the single most important factor in your Greek investment
Why Me: Because the 2026 Golden Visa laws are unforgiving. A single square meter discrepancy can lead to the rejection of your residency application.
Why Me: Because I am not paid a commission to sell you a house. I am paid to find its flaws.
Why Me: Because the biggest risk in Greece isn’t the building—it’s the lack of independent supervision.