RETROFIT | 1 FINSBURY AVENUE would have had major programme implications, which would have added months to the completion date. The reuse strategy was applied pragmatically on the building services plant. For example, Beaven says the boilers were pretty good, but it was much cheaper to replace these than to refurbish them in situ. One element of the building that had to be retained was its distinctive heated, blacksteel and glazed faade system, which was fundamental to keeping the perimeter of the refurbished office floor plates comfortable in winter (see panel, Retaining the heated faade). Reusing the faade had major implications when it came to converting the ground-floor offices into shops and restaurants. Normally with retail, wed put a big louvre at top of the faade. This was not possible because the faade was listed. Instead, new louvres have had to be installed in the reveals formed in the recesses created by the buildings four perimeter stair towers; these cannot be seen when the building is viewed in elevation. The louvres ensure tenants can duct fresh air in and exhaust air out of their demise. In addition, the landlord supplies chilled water, hot water, domestic hot water, cold water and power to each retail unit. Because of the amount of retail on the ground floor, new calorifiers had to be installed to serve the shops and restaurants and the new cyclists showers in the basement. The load profile works well; in the morning, everyone cycles in and uses showers, then, for rest of the day, most hot-water use is retail, Beaven says. Once the project was finished, the team were able to take a step back to assess the impact of reusing plant and systems. While plant reuse requires additional input from the consultants, ultimately, it is the landlord who carries the risk for service provision to the tenant. In this instance, Beaven says the risk was something British Land was prepared to take PERFORMANCE DATA Heating and hot water load 38.43kWh.m-2 per year Total energy load (based on Part L energy modelling by Arup) 121.16kWh.m-2 per year regulated + unregulated 76.23kWh.m-2 per year regulated 44.93kWh.m-2 per year unregulated Carbon emissions (all) 28.2kgCO2.m-2 (based on Part L energy modelling) Annual mains water consumption (BREEAM Wat 01 methodology) 4.70m3 5.12m3 Airtightness at 50Pa 7.24m3.h-1.m-2 0.38W.m-2K 11.55kgCO2eq.m-2 embodied carbon tool PECC. Assumes 0KgCO2eq.m-2 The refurbishment has changed the nature of the working space on because of the benefits to be had from retaining the systems. The building is managed and operated for British Land by Broadgate Estates. Because its not brand new, we expect it will require more maintenance on a day-to-day basis, says Beaven. Although reusing the plant means the consultants have to do much more work than they would if they simply specified a chiller from new, Beaven expects plant reuse to be something Arup will get more involved with in the future: Its not easy, but until the circular economy is running and we have a market to provide refurbished bits of kit, we have to make the best use of what we have. CJ Vital for our wellbeing With Swegons g Air Qualityy Control dynamic y pressure compensation p p functionality, y, GOLD will adapt p to changes g in the system, y taking control and balance to a new level. Fortunatelyy this onlyy requires q the push p of a button, not walking the tight rope! 30 July 2021 www.cibsejournal.com CIBSE July 21 pp26-30 1 Finsbury Avenue.indd 30 25/06/2021 18:42