Commercial Building Stone Cladding — Berlin, Germany

Project Overview

In 2023, a German general contractor approached Phoenix Power Stone for the stone package on a new six-story commercial office building in Berlin's Europacity district, near the Hauptbahnhof. The project required granite facade cladding for the building exterior and granite flooring for the ground-floor lobby and elevator lobbies on all floors.

As an EU construction project, all stone products had to be CE-marked under the Construction Products Regulation (EU 305/2011). This meant full compliance with EN testing standards and documented factory production control — requirements that many non-European suppliers struggle to meet. Phoenix Power Stone had invested in CE compliance infrastructure specifically for the European market.

Stone Products Supplied

Challenges & Solutions

Challenge 1: CE Marking Compliance

Every stone product installed in the EU must carry CE marking under Regulation 305/2011. This requires: initial type testing (ITT) by a notified body, factory production control (FPC) documentation, and a declaration of performance (DoP) for each product. Without this paperwork, the stone cannot legally be installed — period.

Solution: Our ISO 9001-certified factory already maintained FPC documentation as part of our quality system. We commissioned ITT through a European notified body for the specific granite varieties specified. The DoP was issued before the first container shipped. All test results — EN 1926 (compressive strength), EN 1936 (density and porosity), EN 13755 (water absorption), EN 12372 (flexural strength), and EN 14157 (abrasion resistance) — were included in the technical file submitted to the contractor.

Challenge 2: Facade Engineering Requirements

The building's ventilated rainscreen facade system required stone panels with specific flexural strength to meet wind load calculations for a six-story building. The structural engineer specified a minimum 12 MPa flexural strength (EN 12372) for the 30mm cladding panels.

Solution: G654 granite tested at 16.8 MPa flexural strength — well above the specification. We also provided panel-by-panel thickness verification: each of the 5,800+ facade panels was measured with a digital caliper at four corner points and the center. Panels outside the ±1mm thickness tolerance were rejected before packing.

Challenge 3: Precision Fabrication at Scale

Modern ventilated facade systems use metal anchors inserted into kerfs (grooves) cut into the stone panel edges. Every kerf must be positioned within ±0.5mm of the specified location, or the panel will not align on the substructure. With over 5,800 panels, each requiring 4 kerfs (over 23,000 individual cuts), precision at scale was the defining challenge.

Solution: We ran the facade panels as a dedicated production line with a single CNC kerf-cutting machine assigned exclusively to this order. The machine was calibrated at the start of each shift, and every 50th panel was pulled for a full dimensional audit. This was meticulous, repetitive work — exactly the kind of quality control that separates professional stone suppliers from commodity exporters.

Results

• All 5,800+ facade panels delivered within dimensional tolerance.
• CE marking documentation accepted by the contractor without revision requests — a first for this client with an overseas supplier.
• Facade installation completed on schedule with zero rejected panels.
• The building received a DGNB Gold sustainability certification, to which the natural stone facade contributed (natural material, low embodied carbon relative to concrete or steel alternatives).
• Client added Phoenix Power Stone to their permanent approved supplier list for European projects.