Conservation works on the monuments standing within the historic Nizamuddin Area include removal of 20th / 21st century layers of cement to reveal and restore original architectural elements and materials.
Though the cement used in earlier repairs had accelerated the deterioration of the softer 16th century lime plaster, it provided an appearance of ‘ruin’ which was confused by many to represent ‘age’ or ‘historicity’ and thus be of value. By contrast, the conservation works at these sites have been carried out using traditional materials authentic to the building such as lime mortar as used by the 16th century builders and being implemented by master craftsmen familiar with traditional building crafts – knowledge of which has been handed down over generations.
The partnership of the Archaeological Survey of India with the Aga Khan Trust for Culture and in turn the Sir Dorabji Tata Trust aimed at the conservation of Humayun’s Tomb provided an opportunity to establish a model conservation process. The project emphasizes on high level of documentation and research, peer review, supervision, multi-disciplinary and urban landscape approach has been recognized by UNESCO. In view of the significant use of inappropriate modern materials at Humayun’s Tomb through the 20th century, the project could meet conservation objectives of authenticity of material only by giving responsibility to master craftsmen to use traditional materials in a manner used by the original 16th-century builders.
The 2014 National Conservation Policy “acknowledges the adoption of contemporary approaches to conservation”. The policy recognizes “available traditional craftsmanship in the country and the use of traditional building materials and skills as an integral part of the conservation process” and “underpins the role of local communities.”
The Nara Charter (included in the UNESCO Operational Guidelines) defines conservation as “all efforts designed to understand cultural heritage, know its history and meaning, ensure its material safeguard and, as required, its presentation, restoration and enhancement.” This emphasis on making effort required to understand the site through research, study of archival material, architectural documentation and condition assessment to define significance and accordingly formulate conservation strategy and implement repairs was adhered to for the conservation programme at Humayun’s Tomb and adjoining structures.
Though the first few layers of lime plaster are prepared with a mix of lime with sand and brick dust, the final protective layer of lime plaster – only 1 mm thick – is composed of only lime and marble dust. This application of the final plaster layer as part of the conservation effort was essential both to ensure long term preservation and respect (and thus restore) the architectural intention of the original builders. Though intricate ornamental details of the monument were mostly lost and required to be carefully and painstakingly restored – this temporarily results in a ‘new’ appearance of the historic building.
From the onset of the project there was agreement that artificial means such as chemicals would not be applied to give a fake antique appearance to the monuments and instead the natural processes would be allowed to restore a layer of patina – organic growth - that during monsoons would naturally grow on the traditional lime plaster mixed with traditional organic additives such as egg white and fruit pulp, jaggery in the layer below. The organic growth also enhances the protective nature of the final plaster layer as it fills up any cracks that would have developed in the lime plaster Within two years from the completion of conservation works the patina of organic growth has returned to the monuments’ façade and domes. The following images of the various stages of Sunder Burj, explains the conservation strategy undertaken here:
View of Sunder Burj prior to major repairs carried out in 2003-07
Cement repairs undertaken in 2003
The past repairs carried out in 2003 disintegrated, requiring second phase of cement repairs
Removal of cement plaster that was applied in 2003-07
Re-plastering of Sunder Burj in lime mortar
Patina of age returns to the monument