Extending the intervention work, decided according to the situation (one-off, generalised, heterogeneous or homogeneous);
– Architectural and constructive coherence, particularly for changes in shape;
– Reversibility of the intervention works;
– Preservation of identity;
– Promotion of a sustainability perspective;
– Calculation/sizing/verification of existing solutions or those to be introduced;
– Description of works and materials in appropriate technical discourse;
– Description of the works including an architectural and/or construction design;
– Description of the works including a work execution schedule;
– References to specific technical documentation;
– Skilled labour in the field concerned;
– Specific climatic or protective conditions for carrying out the work;
– When it is unusual, prior reflection on the advantages of the envisaged intervention in relation to current alternative solutions;
– Estimate durability and maintenance planning.
As in the case of maintenance strategies, and based on these principles and concerns, it is essential that refurbishing work on roof coverings includes all the measurements and techniques necessary for its success, as understood in a broad sense, and result from a detailed design, supported by a careful survey and by assessing and diagnosing both the structure and the covering.