Retrofitting Ventilation into an Existing Building

SWJ Consulting were brought into this project to help deliver structural alterations as part of the conversion of an existing 1980s office building into laboratory space and retrofit ventilation.  As more people were being moved into the building, the existing ventilation system no longer provided enough airflow, meaning new extract ductwork needed to be installed throughout the structure.

The building itself was a reinforced concrete frame with cavity masonry infill panels between the columns. Each panel contained three large windows separated by relatively narrow 900mm masonry piers. The proposed ventilation design required large openings to be formed through these piers so that new extract ducts could pass through the walls.

When SWJ Consulting joined the project at Stage 4, it had already been identified that the masonry panels would need strengthening once the openings were created, but no practical solution had yet been developed. To make matters more challenging, important data trunking ran continuously across the walls at waist height. Because the building remained operational throughout the works, the trunking could not be removed or switched off at any point.

SWJ Consulting’s role was to develop a strengthening solution that worked around the live services while still allowing the ventilation works to proceed safely.
The solution involved carefully removing sections of the internal plasterboard lining so new steel posts could be installed to reinforce the weakened masonry piers. To avoid disturbing the data trunking, the steel sections were specially detailed with notches cut into them, allowing the new structural supports to fit neatly around the existing services.

Additional remedial wall ties and resin anchors were also specified to improve the stability of the cavity wall panels and help transfer loads safely back into the structure. By strengthening the walls in this way, the new duct openings could be formed without compromising the overall integrity of the building.

This project is a good example of how existing buildings can be adapted and upgraded without major disruption to day-to-day operations. Through practical structural design and close coordination with the wider project team, SWJ Consulting helped deliver a cost-effective solution that allowed the building to be successfully repurposed for its new laboratory use.

If you require advice on structural elements of a project, please get in touch with the Witney 01993 225085 or Southampton office  02381 920656 or email mail@swjconsulting.co.uk