Located in London’s Trafalgar Square, the National Gallery is a world–famous art museum, housing a collection of 2,300 Western European paintings from the 13th to early 20th centuries.

Throughout the years, various industry partners have made a significant contribution to the National Gallery, and over three decades of working together, HDR has been extremely influential in shaping the mechanical DNA of the building, providing complex engineering designs that help maintain a bespoke exhibition environment. Our first project was the replacement of the air conditioning system for the entire west wing of the building.

We have also undertaken numerous comprehensive projects and refurbishments, including the replacement of the central cooling plant with high efficiency equipment, a new energy centre which naturally benefits the Gallery, producing a high degree of their own electricity and using the waste heat to assist in heating the building.

Although the art collection changes very little, the building requires constant attention, and we have been privileged to be involved in many of the gallery exhibition spaces, whereby the exact control of the environment is essential. HDR provided an air conditioning plant room to manage these tolerances that typically range between 69.8 degrees Fahrenheit (21 degrees Celsius) in the winter to 73.4 degrees Fahrenheit (23 degrees Celsius) in the summer, changing by approximately 0.01 of a degree each day from March to May, with 55% relative humidity.

As part of the long–term mechanical, electrical and public health strategy, HDR worked alongside the client, reviewing the high usage of hot and chilled water, in order to implement a solution to reduce long–term costs, vital for a building that must achieve such stringent tolerances continuously.

More recently, HDR was involved in the refurbishment of Room 29, also known as the Wolfson Gallery, in which art was rehung to celebrate the Venetian Renaissance from the 15th and 16th centuries, located on level 2 of the space. HDR utilised the archived documentation from 1996 to guide the refurbishment and used the same blueprints, enabling an efficient process, focusing on the modernisation of the existing systems.

During the refurbishment, picture and cornice lighting fittings were also updated to light emitting diodes (LEDs) and the fabrics throughout the room were reupholstered. The high quality and integrity of the original air conditioning plant installed in 1996 meant HDR did not require replacing the equipment and only recommended minor adjustments, enabling smooth and timely delivery.

From May 2024 to May 2025, the National Gallery will commemorate its bicentenary, celebrating the past and looking to the future, with a yearlong festival of art, creativity, and imagination. HDR has provided an exceptional environment for the National Gallery to enter its third century of operation, as this iconic institution, in the City of Westminster, continues to welcome visitors from across the globe to experience the astounding array of masterpieces for decades to come.