Surveyors map out the ruins of Xiyang Lou (Western mansions). [Photo provided to China Daily]

Guo is an advocate of the ideas of her teacher Liang Sicheng on protecting cultural relics and historic sites. This approach puts a premium on protective measures that manage changes over the years and help buildings survive by bring them into a proper state of repair rather than turning old buildings into ones as new as the original ones were when they were built.

It is impossible today to make many things that would have been integral to the Old Summer Palace because the materials, tools and methods people used 150 years ago were vastly different to what people use now, Gou says.

For example, Hanjingtang, which Emperor Qianlong built for his retirement, was constructed using the finest techniques and earth that was rammed layer by layer, she says. If it was rebuilt today, people would simply use concrete, with the attendant loss of historical integrity, she says.

In addition, emperors were able to call on the services of the best artists, artisans and workers around the country to build the palaces, something that cannot be replicated today, she says.

In 2009 Guo's team, comprised of specialists in archaeology, history, architecture, gardens, 3D modeling, virtual reality technology, databases, visual arts and internet engineering started using digital technology to bring the Old Summer Palace back to life, thus allowing contemporary audiences to appreciate its splendor.