Shelbourne Property Group spent millions refurbishing number 75 St. Stephen’s Green in 2004, creating a contemporary glass façade which belied the challenges associated with the building services within.
Over the years the building has had facelifts and fitouts, but the issue of air: ventilation, heating and cooling had never been properly addressed until Hudson Advisors awarded the contract to mac-interiors to fully upgrade and refurbish the mechanical and electrical services in the building (HVAC). Each floor is tenanted with high value clients whose day to day activities could under no circumstances be compromised by the works. This was part of the reason why mac won this contract, as it required an experienced, specialist fit out contractor who could understand and navigate the unforeseen challenges uncovered when working in the plenum spaces.
The floor void in 75 is untypically confined, due to its 200mm depth and a confusion of existing cabling. We needed to achieve air-tightness to 50 PA in the floor void in order to optimise the efficiency of the new HVAC systems. Existing data cables, cracked concrete slab throughout, and fissures in the external glazing all conspire to thwart the attainment of this stringent air-tightness standard. These works had to be carried out on a phased basis, with a 4 week turnaround for each area (approx. 5,000 square feet each) and a very tight, strict programme and handover for each area. All the while we are operating in a heavily tenanted building and much of the works are completed out-of-hours due to a noise restriction of 35 DB to minimise impact on the people operating on the tenant floors.
However, at mac-interiors we love nothing more than a good challenge so we went ahead and embraced the constraints posed by this iconic building – and we wrote the methodology to overcome them. We devised a strict protocol to achieve air tightness while the first test area was being carried out:
- Surveys
- Lifting services
- Completely clean and seal the floor
- Seal perimeter with mastic, air seal tape and carry out air testing
Our methodology has become a benchmark of expertise in the area of air tightness and we have created a document with detailed photos and drawings showing the layering of the cables and outlining the various procedures employed to overcome the problem. Since we devised and rolled out this methodology, and trained our onsite team we have carried out 22 test areas in succession and passed the air pressure tests with flying colours.
We will complete the final area of the original contract in 4 weeks from now. The final frontier. However, when this area is handed over we will be continuing with our other works in the building which we have been contracted to carry out – fire protection treatment works and associated refresh work.
We are relishing the thought of the next challenging building – perhaps it’s just around the corner? Stay tuned for more.
