IES Consulting carried out the LEED Energy Modelling for this Core and Shell Office Refurbishment of one of Dublin’s most iconic buildings, which is on track to receive a LEED Platinum rating.
Previously the Bank of Ireland Headquarters, this building is very iconic to the city of Dublin. The development consists of three 1970’s era Core and Shell (CS) office buildings that sit on a podium, above an underground car park. The buildings are undergoing a full renovation, not only to improve their energy performance, but also to exceed current building energy regulation standards.
The client stipulated that they wanted to achieve a LEED Platinum rating for the buildings and this is where the IES Consulting team’s extensive knowledge and experience of the LEED process proved to be invaluable. To achieve a LEED Platinum rating, it is necessary to target all of the energy points. Using the VE software, IES Consulting were able to explore, in detail, alternative compliance paths and innovative solutions to achieve maximum energy savings for the client.
The design team incorporated a number of high-efficiency energy saving features in this project, including, but not limited to: high efficiency lighting fixtures; a high performance envelope upgrade; high efficiency chillers and boilers; CHP; and ice thermal storage.
A particularly challenging aspect for the project team was the refurbishment of the building façade, which is renowned in Dublin for its bronze cladding. All three of the buildings are protected structures, meaning that all of the facades had to be stripped from the buildings and refurbished with new glass. An innovative ventilated double-skin façade, with automated blinds located within the façade cavity, was added to the corners of the buildings in order to alleviate comfort issues. This also helped to reduce heating and cooling requirements and was a significant factor in improving the energy efficiency of the buildings, accounting for 45% of an overall 77% reduction in space heating energy.
A reduction in lighting energy consumption was another important factor in pursuing the LEED certification, since this will account for a large proportion of the buildings’ overall energy consumption. In order to ensure that the energy savings predicted by the energy model would give a true reflection of the buildings once in operation, the client will impose a tenant lease agreement to limit the lighting power density in all office levels to 4.75 W/m2 (0.44 W/sf). Another requirement of this will be the installation of occupancy sensors and automatic daylighting control that is capable of reducing electric lighting power to less than 10% at maximum dimming.
The project achieved total energy cost savings of 44.3% (rising to 59.1% using an Exceptional Calculation Method in accordance with ASHRAE 90.1 Table G3.1.5 (f)) and is expected to attain the desired LEED Platinum certification.