3 Policies Regarding CONSERVATION of World Heritage Properties
3.5 Factors affecting properties
3.5.7 Local conditions affecting the fabric
Conservation of cultural and natural heritage is at the core of the Convention. Conservation includes effective and active measures that can be taken by States Parties to ensure the identification, protection, presentation and transmission of heritage.
There is no single definition of conservation in relation to both cultural and natural heritage. However, with regards to cultural heritage ‘all operations designed to understand a property, know its history and meaning, ensure its material safeguard, and, if required, its restoration and enhancement’ could be part of its conservation (Nara Document on Authenticity). Conservation of natural heritage refers to the protection, care, management and maintenance of ecosystems, habitats, wildlife species and populations, within or outside of their natural environments, in order to safeguard the natural conditions for their long-term permanence (IUCN).
The Conservation theme includes policies related to protection, management, monitoring, impact assessments, factors affecting the properties, tourism and sustainable development.
Environmental or biological factors that promote or contribute to deterioration processes of the fabric of heritage sites. Since decay effects cannot be attributed to a single factor, consider all elements.
Wind (For example: Erosion, Vibration). Relative humidity. Temperature. Radiation/light. Dust. Water. Pests. Micro-organisms.
Synthesis based on relevant Committee decisions
The World Heritage Committee requests States Parties to undertake a comprehensive assessment of the conditions as well as an analysis of ways to address the underlying causes of local conditions affecting the fabric, and to elaborate a comprehensive strategy to address the impacts, including priority emergency measures, mitigation measures and an intervention programme (based on Case law on decisions on the State of Conservation). 
 See for example Decisions , , , , , , , .