The National Portrait Gallery in London has undergone its biggest redevelopment since it first opened its doors to the public in 1896. We were tasked with integrating state-of-the-art engineering systems as well as safely re-introducing daylight into the galleries through windows which had been blocked up for nearly 100 years.

This sensitive restoration breathes new life into the historic buildings, providing the best possible environmental conditions for both the artwork and the people inside the gallery.

The Grade I listed National Portrait Gallery houses the most extensive collection of portraits in the world. Working alongside Jamie Fobert Architects and Purcell, Max Fordham acted as the M&E, Lighting and Acoustics consultants on the project. Our goal was to improve the internal conditions of the gallery in the most sustainable, energy-efficient, and sensitive way possible.

The redevelopment included the creation of a new public forecourt, a spacious entrance hall, new retail and catering facilities, and a new learning centre. Office spaces have been converted into beautiful, top-lit galleries on the first floor, extending the public gallery space by around 20%. There has been a complete re-hang and re-interpretation of the extensive collection of artworks across forty refurbished galleries which now presents an updated and more diverse selection of portraits.

For significant heritage projects of this scale, our engineering solutions need to be sympathetic, flexible, and most of all inventive, in order to meet modern expectations whilst protecting the heritage of the building. We strove to find the right balance between providing better conditions and greater functionality while respecting the historic fabric of the institution.

The new entrance to the Gallery features doors designed by Tracey Emin depicting 45 hand-drawn female portraits cast in bronze. © Olivier Hess 

Lighting

The lighting design gives more presence to the entrances, introduces daylight into the galleries, and addresses the problem of ‘gallery fatigue’ to create a flexible, characterful, energy-efficient and healthy installation across the site.

Many of the gallery’s large windows and rooflights had been blacked out in the 1930s. The windows remained shuttered in order to conserve the works and create more usable space below. Now, all of these have been uncovered and fitted with layers of light-filtering fabrics and films, so that the artworks are protected whilst allowing natural light into the galleries for the first time in decades.

Max Fordham built on our experience of designing and analysing daylit galleries at Westminster Abbey, Tate Britain and the Hayward Gallery to create high-resolution solar maps of the NPG which simulate the contributions of sunlight and skylight 8000 times over the course of a test year, using existing measured and future climate data.  Each simulation requires the accurate tracing of over 200 million rays of light, and the team used the results to plan the exhibitions, design the artificial lighting and test different approaches to window and rooflight treatments.

The outcome of this work is a gallery re-connected with its surroundings, one where visitors and staff can easily find their way about and where the subtle changes in natural light over the course of each day offer a uniquely healthy and stimulating visual environment.

We repurposed the vast system of rotating sun louvres installed on the roof in the late 1990s as fixed shades by taking advantage of the latest developments in building physics modelling. We created a ‘digital twin’ and used flexible software codes that allowed us to accurately predict and optimise annual lux exposure for a range of possible options.

Our lighting approach included:

• New installations of light fittings which are carefully integrated into the historic architecture, inside and out, to best display the heritage assets of the museum
• Characterful lighting illuminating the large new entrance hall, and expressing the architecture of the historic grand staircase
• A hi-tech system of low-energy LED fittings controlled by Bluetooth which enables the gallery to use all their space more flexibly and to have better control over the visual environment
• Sophisticated movement and daylight-linked controls across the site to save energy
• Low-transmission blinds, films and fabrics to introduce controlled daylight in gallery spaces, creating a dynamic environment which greatly reduces the risk of museum fatigue and where the need for additional artificial lighting is minimised
• Repurposing the old rooftop louvre system using the latest understanding in conservation to deliver the right conditions without energy and resource-intensive new installations  

We created detailed solar maps of the National Portrait Gallery using existing and future climate data, with each simulation requiring the accurate tracing of over 200 million rays of light.

Environmental Engineering

Our M&E design focused on maintaining appropriate environmental conditions for the preservation of art and minimising the use of energy in ways that are sensitive to the original features of this historic building.

Energy-saving measures have been adopted wherever possible, such as including heat recovery on ventilation systems, whilst existing galleries have retained and redeveloped the environmental and ventilation strategies already in place. Our interventions included: 

• New services to galleries and public spaces, discretely integrated and hidden behind building fabric, respecting the architectural vision
• Enhanced, resilient electrical infrastructure to support the running of critical gallery systems, with multiple levels of back-up
• New, low-energy mixing and displacement ventilation in new spaces. A ventilation system that recovers heat from inside the building and mixes it with fresh air, to minimise energy (by reducing the need for independent heating) while providing comfortable internal spaces. This is known as mechanical ventilation with heat recovery (MVHR).
• Maximising the re-use of existing plant/equipment in existing spaces, where suitable and possible, to minimise the carbon impact and cost of the redevelopment
• A hugely increased electrical scheme, with an enhanced, modern IT installation to support greater interactivity and digital access throughout the building
• Disconnecting services to the East Wing (previously from the National Gallery), allowing it to be fully served from NPG systems and independent from the neighbouring gallery
• New visitor lifts and replacement escalator to improve access for all

Acoustics

Our acoustic design focused on creating a peaceful environment for users of the gallery. We designed acoustically absorbent finishes to some gallery spaces to improve the experience for busy events and functions by controlling reverberation.  

The new entrance hall and multi-storey atrium have been modelled using 3D acoustic ray-tracing software. 

To aid the design of new areas for relaxation and education, we assessed noise from the nearby Charing Cross Road and vibration from underground trains. 

 Acoustic absorption attenuates external noise as it passes through the entrance hall and controls reverberation in multi-level hall