The development aim was to transform the historic Mob Store at Berwick Barracks into a vibrant community cinema. This initiative aimed to preserve the architectural heritage of the barracks while providing a modern, accessible space for film screenings, cultural events and community gatherings.

The project involved upgrading the building envelope to provide high levels of sound insulation and form a dedicated cinema space with raked seating for 98 people.

Located in a tranquil area, the background noise is dominated by waves crashing on the beach and sea breeze through the trees. Nearby residents were understandably concerned about the conversion of such a historic building, and the impact of a cinema playing loud modern ‘blockbuster’ film soundtracks.

Onerous planning conditions were set in relation to noise due to the proximity of surrounding dwellings and gardens. We guided the local authority in setting appropriate conditions for cinema soundtrack egress, as well as guiding the client through the design solutions needed to achieve the criteria.

The building comprises thick masonry walls and a pitched roof of slates on timber sarking boards. Initial benchmark acoustic testing demonstrated that the poor sound insulation of windows and doors meant typical cinema soundtracks would be unacceptably loud at adjacent dwellings.

Enhancement solutions included a new ceiling underneath the existing timber roof structure, the in-fill of window openings and new acoustic door lobbies to all entrances and exits. The precise weight and sound insulation of the existing roof was unknown, so computer modelling was employed to predict the range of expected sound insulation improvement that could be expected from roof enhancement options. This included sensitivity analysis to assess uncertainty and risks in arriving at the most appropriate roof upgrading solution.

Due to the historic nature of the building, some unconventional upgrades were needed. For example, there was concern that blocking up the historic windows may lead to condensation and damage. To control this, acoustic vents were installed within the internal wall lining at each window reveal to provide an acoustically attenuated air path. While reducing the sound insulation of the window in-fills, the overall impact was carefully managed in terms of expected breakout noise to nearby dwellings and was assessed using 3D computer modelling.

The cinema is served by a new displacement ventilation system with supply air introduced below the raked seating and extracted at high level. We advised on the building services noise control design and specified the attenuator requirements for the systems. Some simple design strategies were employed such as locating all external plant on the side of the building facing away from the nearby housing, avoiding the need for any acoustic screens, louvres or enclosures.

The acoustic quality of the cinema space is well controlled. We advised on the finishes which are a combination of stretched fabric wall coverings and slatted timber veneer wall panelling, as well as upholstered seating and carpeted floor.

Shortly before completion, initial sound insulation testing was undertaken. This was done by simulating cinema soundtracks on an independent loudspeaker, allowing any weaknesses and snagging to be identified before the building was complete and the cinema’s full sound system was installed. The tests indicated that the planning condition criteria were achieved with a sufficient safety margin and that any structure borne sound from the full sound system, incorporating wall mounted speakers, would be adequately controlled. This was confirmed by testing using the full cinema sound system on completion.

The project was a great example of effective collaboration with stakeholders and the client, the design team and the local authority.