Structural rehabilitation of a historic building in Puerta del Sol, Madrid

Comprehensive intervention in a Grade 1 listed building

KALAM has carried out the structural rehabilitation and the restoration of the building envelope of a historic building located in Puerta del Sol, Madrid, one of the most heavily trafficked urban areas in the city.

The building, listed as Grade 1 due to its singularity, was constructed between 1857 and 1862 and presented the additional challenge of a potential change of use from residential to commercial, which required extensive structural reinforcement.

Technical complexity and methodology of the proposal

The intervention stood out for its high technical demands, particularly in the structural field. The protection status of the building, its location, and the increase in loads resulting from the new use made rigorous planning necessary.

The construction management and the design were developed by RCCYP Arquitectura, whose initial analysis made it possible to define specific solutions for each element and condition of the building.

Among the determining factors for the success of the proposal were:

• Collaboration among the parties involved, architecture, construction, and ownership, with coordinated management and shared objectives.
• A thorough preliminary study and a detailed design that facilitated technical decision-making.
• The involvement of specialists at all stages, with professionals experienced in execution and planning.
• Experienced technical teams, with a proven track record in interventions in urban centres and protected buildings.

Structural intervention: recovery and reinforcement of the original structure

Over the course of its 150-year history, the building had undergone transformations and interventions in which steel had been used as a reinforcing material or for subsequent adaptations. The property exhibited pathology resulting from its age and from causes such as moisture infiltration, which had affected not only the original timber but also later interventions.

In general terms, the intervention restored the building’s original structural solution of timber framing with brick infill and timber floor structures, primarily using wood for this purpose.

The proposal prioritised the conservation of original elements in good condition—such as posts and beams—and the design of reinforcement solutions at points where greater load-bearing capacity was required, the recovery of elements that had lost vertical continuity within the overall timber frame, and the consolidation of those that were damaged.

The interventions in the floor structures included mixed solutions with the installation of connectors and compression layers, as well as the use of lightweight materials and timber in areas that required reconstruction.

A complete renewal of the roof was carried out due to its poor state of conservation, while preserving the traditional construction solutions and the original support system.

To adapt the structure to the new load scheme, different types of structural timber were combined:

• Sawn timber, for the replacement of posts and wall plates.
• Laminated timber, used for new joists and lintels.
• Laminated veneer lumber, used for section increases and specific reinforcements.

The project also included the reinforcement of the metal structure of the retail premises, the consolidation of the foundations by means of pile caps and micropiles, the recovery of the original interior openings, and the restoration of the brick vaults in the basements, combining criteria of structural safety and heritage preservation.

Restoration of the building envelope and protected façades

The scope of the intervention also included the comprehensive restoration of the building envelope and the improvement of the building’s thermal performance through the incorporation of insulation in both the interior courtyards and the roof areas.

The façades with singular protection required a particularly careful working process. Cleaning and restoration works were carried out on the stone plinth, and the rendered surfaces and ornamentation of the upper levels were restored. Likewise, the joinery was replaced or restored, respecting its original design and materiality.

Management and coordination in a highly complex urban environment

Puerta del Sol is a location with very high pedestrian traffic and significant logistical constraints, which meant that construction planning required a precise and flexible operational design. Material handling and debris removal operations were carefully scheduled and adapted to the specific characteristics of the surrounding environment.

The scope of the project also included interior works at Casa Labra, adapting the construction activities to the operation of this historic establishment. Coordination between the designers, the owner, and KALAM’s technical teams made it possible to move forward without disruption and to ensure the proper execution of the works.

KALAM’s experience in heritage conservation and urban rehabilitation

This project adds to KALAM’s extensive track record in building rehabilitation and the restoration of built heritage in central Madrid. Its specialized team has carried out comprehensive rehabilitation works at locations such as Atocha 8–10, Atocha 40, Conde de Romanones 5, Farmacia 3, and San Roque 1, as well as interventions in numerous buildings around the Callao and Gran Vía areas, including the restoration of historic façades such as those at Canalejas Centro.

This rehabilitation project is a strong example of KALAM’s ability to tackle complex structural interventions, work with traditional materials such as wood, and manage construction works in locations with significant urban constraints, providing technical expertise, experience, and a deep understanding of built heritage.

See more of Full Building and Structural Rehabilitation