Cemplas were called upon to advise on the condition of this structure and to install a method of waterproofing to ensure the main memorial sanctuary pond was able to contain water as well as prevent external ground water contaminates from seeping through the structure and into the pond.

The sanctuary was originally built in 1924 to honour the naturalist William Hudson who helped to establish the RSPB. Over a period of 5 years the Royal Parks have been working to enhance the sanctuary which is one of the few woodland areas remaining in central London.

The restoration works included lifting vegetation to provide natural light, building hedges for nesting spaces and planting native flowers for food sources. The next step was to restore the memorial ponds and stonework to provide an enriched environment for birds, small mammals and amphibians as well as invertebrates in a natural habitat.

The sanctuary is due to reopen soon and will provide a relaxing environment for all park visitors to enjoy.