How Ancient Craft, Lab Science, and Technology Keep a 600-Year-Old City Alive.
Hidden behind the bustling streets of Beijing sat a city enclosed behind red terracotta walls and rows of yellow-glazed eaves. The Forbidden City is more than a tourist attraction—it’s the most well-preserved, complete example of a Chinese imperial palace: complex timber halls, imposing painted beams, tiled roofs, and various mini-palaces organized in a complicated fashion, embodying power, ritual, and material mastery since the 1400s. To this day, the pristine condition of the palace remains a mystery to many, but it mainly can be attributed to combining centuries-old craftsmanship, modern technology, and preserving the city as we see it today.
Architecturally unique—yet fragile.
Unlike the Bourbon monarchy's Palace of Versailles or the Romanovs’ Winter Palace, the Forbidden City is built in wood: interlocking timber frames, bracket “dougong” sets, and polychrome finishes that make the structure both imposing and visually complex. Despite being unique architecturally, the wood and organic pigments are highly sensitive to moisture, pollution, and thermal cycling. The glazed roof tiles and gilt ornaments are threatened by abrasion and acid deposition from Beijing's polluted air, making these structures require constant maintenance and historical preservation.
Preservation problems:
Conservators face a mix of material, environmental, and human pressures:
Material decay: polychrome paint and timber elements naturally age from weathering, insect infestations, or the delamination of varnish, requiring preservationists to adopt time-consuming practices of repainting elements traditionally.
Urban Growth: Beijing’s rapid growth, shifting climate, and constant pollution increase chemical attacks and moisture, damaging structures. Additionally, the millions of visitors wear steps and floorboards, making preservation efforts difficult.
Legacy repairs: earlier 20th-century or wartime repairs (WWII and the Chinese Civil War) sometimes introduced materials that clashed with traditional ones, creating removal and mitigation challenges.
Modern Practice: craft, science, and digital documentation
1. Traditional craft remains central
The most common conservation approach is to use the same traditional craft to repair structures and painted surfaces. The Chinese government hires master carpenters to hand-carve replacement components through traditional techniques, such as mortise and tenon joinery and handmade pigments through minerals and lacquer formulas for retouching, preserving both historical and visual authenticity.
2. Scientific diagnosis using Technology
The first steps towards conservation involve using technology. Conservators gather data through nondestructive means: X-ray diffraction, portable XRF, Raman spectroscopy, microscopy, and microchemical tests. These methods identify specific pigments, varnishes, corrosion, and contamination that need to be treated, allowing conservators to gain insight into methods of repair, material selection, and cleaning methods, ensuring the material isn’t harmed in the process. Laboratories attached to the Palace Museum and collaborating research centers run these analyses for both buildings and the museum’s vast artifact collection.
3. Digital recording and modeling
Combining LiDAR point clouds, aerial and ground photogrammetry, and multispectral imagery has become standard practice within the city’s walls. These data sets allow for condition mapping, planning restoration sequences, and digital ‘twin’ renders, allowing researchers to experiment and find the most effective way of preservation while reducing risk. The digital record also preserves a time-stamped archive of conditions before intervention, essential for transparency and future research.
Transferable lessons for other heritage sites
Document first, intervene second. Accurate 3D records lower risk and create a permanent archive.
Keep craft central. Skilled artisans and historians are essential to preserving the original construction and materials, ensuring authenticity.
Use science to choose treatments. Analytical methods prevent misapplied consolidants and irreversible damage.
Make digital replicas public. Virtual access can make archival material more accessible, and broaden educational outreach.
Conclusion:
The Forbidden City is not just a tourist attraction, nor another impressive imperial palace; it is a living historical and cultural archive that requires care and attention. Conservation protects more than structure—it preserves the voices of its Ming-dynasty artisans, their unique craftsmanship, and the rich history embedded within the palace walls. By integrating modern science with historical practice, we ensure that this confluence of architecture, culture, and knowledge not only survives but also remains vibrant and relevant.
