Securing the future of an historic venue
Built in 1900, Perth Theatre is a Category B listed building with, what was once, an opulent Art Nouveau main auditorium. BuroHappold Engineering was engaged to help conserve, restore, and upgrade the Edwardian building to current theatre standards of accessibility, technology, and user experience.
The existing 500-seat auditorium and back-of-house dressing rooms were augmented by a new-build extension (box-in-box). This included a 200-seat studio theatre with retractable seating, flexible performance space, and front-of-house reception, together with an entrance foyer housing a bar, kitchen, and restaurant. The project also supported a vibrant production company and its lively community programme by creating new performance, social, and workshop spaces.
The client’s brief asked for improved ventilation and heating for the main auditorium while taking account of running costs and energy usage, all within a tight budget.
The existing auditorium heating and ventilation was proving a challenge for the theatre. The problem was that the system shot large volumes of air at high velocity into the space via a single louvre at the back of the theatre. Not surprisingly, this made for an uncomfortable environment and created an uneven temperature and ventilation profile across the space.
In addition, both the auditorium and the new-build studio theatre had a noise restriction of NR25 for services (the Noise Rating curve determines the acceptable indoor environment for hearing preservation, speech communication, and annoyance). Given the large volumes of air required and tight spaces allocated to service location and distribution, achieving this rating required creative engineering and collaborative working with the acoustics experts.
Theatre consultants, Charcoal Blue, provided the brief for the stage engineering, stage lighting, and audio visual. Through close collaboration with Charcoal Blue and architects, Richard Murphy Associates, our engineers tackled the complex service infrastructure for the high spec, highly-serviced theatre spaces which had to perform well, technically, in keeping with conservation requirements.
BuroHappold’s heating and ventilation solution blended services perfectly into the newly refurbished space, providing the required standard of air quality without design compromise. We carried out a number of computational fluid dynamics (CFD) analyses to demonstrate how this solution would improve comfort within the existing auditorium space and new-build studio theatre.
The team brought in energy-efficient mechanical ventilation systems to ensure air flow in the main theatre, community rooms, and foyer. The duct routes of these systems were carefully threaded through the back of the auditorium to minimise their impact on the listed interior.
A displacement ventilation system for the new-build studio theatre supplied fresh air at low level via perimeter diffusers (exhaust air was removed at high level). To keep noise levels to a minimum and beat the space restrictions, the main ductwork run to the studio theatre was positioned externally, on the studio theatre roof, with branch connections piercing the surface to serve displacement terminals within. Each of these penetrations was planned in close collaboration with the acoustics team to ensure all attenuation, acoustic seals, and airflow rates were in compliance with the strict noise regulations.
The low slab-to-slab heights within the new-build extension were particularly challenging from a services perspective. So we adopted a vertical services strategy and horizontal services were avoided as far as possible. However, as lighting was required across the space, we had to recess lighting and associated conduit runs into the new extension slab soffits.
A new substation and a bigger main distribution panel were required to meet the increasing demand for power. As height in the basement was restricted, we opted for a particular switchboard that kept compartment sizes to a minimum.
Due to the complex cabling network distributing to the stage lighting, audio visual, and stage engineering service boxes, each cable had to be identified, its route identified, and containment routes checked and closely calculated to ensure adequate spare capacity for future expansion.
The team also reconfigured sound decks and lighting positions to optimise performance, as well as assisting in the provision of a new technical lighting gallery, follow-spot space, and an audio description room located way up in the ‘Gods’.
Edge lighting and colour-change capacity for the principal entrance on Mill Street provided a striking yet functional facade. A large LED screen was integrated to display promotional assets.
New hoisting systems were introduced to allow safe and convenient ground-level access to the chandelier and all lighting rigs for maintenance and cleaning.
To get around the major on-site space restrictions, we positioned plant on the roof. Being in a busy city centre, the equipment was fully screened and hidden from surrounding streets and buildings.
A new lift was designed for the new-build extension and the existing lift extended to reach all floors. Other accessible features included a disabled refuge intercom system, alarms in all accessible toilets, and an induction loop at the reception desk, ticket office, and ground- and first-floor bar areas. For improved visibility we incorporated a handrail and tread lighting, which gives a more-even light distribution across the stairs.
Experimenting with the Edwardian cultural form and reviving the theatre’s opulence has performed an invaluable service for the local community. This much-loved venue has been given a new, contemporary lease of life and the freedom to flourish, attracting whole new generations to delight in its uniquely dramatic character.
Services and approach
When we integrate our specialist teams around an approach, the benefits to the client multiply