Material Sovereignty
We source 80% of materials from French quarries and mills, with full traceability logs. Every concrete batch is certified.
Batch ID: FR-Q77-2026-0412
Since 2008
Building
for the
Century.
Parisian Precision
Haussmann Expertise
Structural Integrity
Solidron is not a contractor. We are custodians of structural truth. From our base at 107 Boulevard Richard-Lenoir, we translate century-old Parisian masonry techniques into modern, resilient frameworks.
Explore Our MethodologyFrom Parisian Foundations to Global Frameworks
Solidron began not with a business plan, but with a failing building. In 2008, engineer Marc Dubois purchased a dilapidated 19th-century apartment in the 11th arrondissement with a singular goal: restore it to its original strength without compromising its soul. The methodical process of preserving Haussmann-era details while upgrading structural integrity became our founding blueprint—the "Parisian Precision" methodology.
"The materials and methods developed for the stone and timber of Paris are inherently timeless. We simply adapted the logic, not the principle."
— Marc Dubois, Founder & Lead Engineer
This philosophy of structural honesty—exposing load-bearing elements, specifying high-grade materials, and building for thermal and acoustic permanence—proved its value. By 2015, our method was ready for scale. The La Défense office complex wasn't just another project; it was a stress test. We applied the same reverence for material traceability and acoustic performance to a 15,000-square-meter commercial build. The result, delivered on time and under the stringent Parisian commercial codes, became our credential for larger-scale contracts.
Today, our projects span Europe, but our criteria remain anchored in that first, quiet apartment. Every decision is filtered through a single question: Will this detail outlast its purpose? It's a question that moves us beyond quarterly targets and into the realm of legacy.
Key Milestones
2008
First Project: 11th Arrondissement Restoration. The laboratory for Parisian Precision.
2015
Commercial Expansion: La Défense Office Complex. Proof of scalability for French building codes.
Present
Current Focus: International Heritage Restoration. Applying proven methods to diverse climates.
Method Note: Robustness Evaluated
We validate longevity through a multi-point inspection protocol. No project closes without a documented material palette (origins, specs), a structural soundness report, and a 5-year maintenance plan. This audit trail is our standard contract appendix.
Trade-off: Cost vs. Timeline
- • Option A (Standard): Use readily available, lower-grade steel. Benefit: 15% faster procurement. Risk: Higher long-term corrosion probability.
- • Solidron Approach: Specify French electro-galvanized steel. Benefit: 50-year corrosion resistance. Mitigation: We pre-order materials 8 weeks in advance.
- • Outcome: The initial delay is offset by eliminating future repair costs and client disputes.
The Solidron Standard
Our five non-negotiable pillars. Every project, from a single apartment to a commercial complex, is measured against these criteria.
Acoustic Integrity
Every wall assembly is tested to meet or exceed 55dB sound reduction (Rw + Ctr > 50).
Standard: DTU 49.1
Thermal Bridge Elimination
Detailed insulation continuity prevents condensation and energy loss, certified to Passivhaus standards.
U-value target: ≤ 0.15 W/m²K
Structural Honesty
No hidden steel. All load-bearing elements are visually accessible or documented in cutaway diagrams.
Client-Ready Cutaways
Future-Proofing
All electrical and plumbing conduits are oversized by 25%. This isn't waste; it's foresight, allowing for future upgrades without demolition.
Commitment: 40% more accessible pathways than standard builds.
The Team Behind the Stone
Sophie Laurent
Lead Architect
"The best new building is one that doesn't forget its past."
Specialty: Adaptive reuse of Haussmann-era structures.
Jean-Pierre Moreau
Head of Engineering
"Vibration isn't just noise; it's a data stream for structural integrity."
PhD in Structural Dynamics. His analysis saved the Saint-Germain project from resonance issues.
A
Amélie Chen
Sustainability Director
Micro-Scenario
Before pouring any concrete, she audits the batch plant. Last month, she rejected a delivery with 5% less recycled aggregate than specified.
Decision Criteria
All materials must pass a "Lifecycle Weighting" test: 40% performance, 30% origin, 30% end-of-life recyclability.
Thomas Leroy
Project Manager
Pitfall Avoided
Scope Creep
Protocol: Daily time-stamped photo logs and a shared "Change Log" with immediate cost/impact analysis. Any deviation is documented before proceeding.
"Surprises are expensive. Transparency is cheap."
Pierre Dubois
Master Stonemason
4th Generation. He hand-carves the signature Solidron keystone on every principal facade. It's our visual warrant.
Role: Ensures tactile quality and tradition.
Case Study
The Marais Loft: Engineering Light
A 1920s warehouse in the Marais, dark and divided, was the canvas. The client's brief: "Bring the outside in without losing the soul of the space." The challenge was structural: the original timber frame couldn't bear the weight of traditional masonry walls needed for modern insulation.
Our solution was counter-intuitive. We removed interior partitions, leaving the raw timber beams exposed. Instead of thick walls, we applied a continuous layer of breathable internal insulation (wood fiber boards) and a vapor-open membrane. The new structure—a floating steel staircase and glass balustrades—became a lightweight scaffold, not a burden on the old frame.
Constraints We Worked Within:
- • Historic Commission: No external wall alterations permitted.
- • Client Timeline: 5-month maximum occupancy loss.
- • Thermal Code: Must achieve RT 2020 (French 2020 building regulation).
Outcome: Energy bills reduced by 40%. Usable space increased by 30% via strategic reconfiguration.
Trade-off: Sacrificed a small storage closet for a double-height atrium.
The Cost of Cutting Corners
A builder's glossary. Understanding the terms helps you see where value is truly engineered—and where it's often lost.
Flash-and-Batt
Insulation Method
The Industry Pitfall
A cheap method that sandwiches fiberglass batt between a vapor barrier and drywall. It often traps moisture, leading to mold and rot inside the wall cavity.
The Solidron Alternative
We use continuous exterior insulation with a ventilated rainscreen. This creates a continuous thermal break and allows the wall assembly to dry naturally.
Value Engineering
Project Term
The Industry Pitfall
Often a euphemism for cost-cutting, stripping out materials or detailing without considering long-term performance.
The Solidron Definition
We engineer for value, not just low cost. Example: Using higher-grade steel upfront reduces lifetime maintenance. We re-allocate budget from low-impact areas to high-stakes details.
Change Order
Contract Term
The Industry Pitfall
A surprise invoice for unbudgeted work, often a source of conflict and distrust.
The Solidron Protocol
All potential changes are documented in a shared digital log with a cost/impact analysis before client approval. No surprises, just documented decisions.
Subcontractor
Team Model
The Industry Pitfall
A disconnected team member with misaligned incentives, often leading to quality inconsistencies.
The Solidron Model
We work with a core team of long-term partners who share our liability and standards. They are team members, not outsiders.
Completion Date
Schedule Term
The Industry Pitfall
A hopeful guess, often missed due to weather, supply delays, or poor planning.
The Solidron Commitment
We build a 15% "weather buffer" into every schedule. We communicate potential delays 2 weeks in advance. Our finish date is a forecast, not a fantasy.
Ready to discuss a project that is built to last?
We schedule consultations to understand constraints, timelines, and ambitions. Your first visit is an audit, not a sales pitch.
Solidron • 107 Boulevard Richard-Lenoir, 75011 Paris, France
+33 1 58 30 30 10 • [email protected]
Mon-Fri: 9:00-18:00 CET