Built between 1699 and 1705, the Rubrics is the oldest building on the Trinity College Dublin campus, and Ireland’s longest-serving purpose-built residential building.
However, the elegant 325-year-old red brick building – which is listed as a Protected Structure and Recorded Monument and still used for accommodation – required an extensive upgrade to provide modern rooms and studio apartments to enhance living conditions for students and teaching staff.
Given its historical significance, the refurbishment had to both safeguard the building’s historical, architectural and cultural significance while upgrading its fabric for modern use.
The university also needed to achieve substantial energy savings and reduce greenhouse gas emissions, aligning with the college’s commitment to sustainability.
This presented the university with a significant challenge, which a team of experts including AECOM helped to meet – with award-winning success.
Innovative use of geothermal energy to improve energy efficiency and cut carbon emissions
Our team was appointed on a Pascall + Watson-led design group to provide mechanical, electrical, civil and structural engineering services – as well as Project Supervisor Design Process (PSDP) services – for the restoration and deep energy retrofit of this landmark building.
The building’s age and historical value meant that traditional retrofit methods were not always applicable, necessitating innovative approaches that balanced energy efficiency with conservation.
We conducted an extensive feasibility study that examined a range of options to determine the best heating method for the building. This involved assessing each option based on several criteria, including energy consumption, carbon dioxide (CO2) emissions, and the impact on both the building’s conservation and the broader campus environment.
The analysis revealed that, as well as having the lowest carbon dioxide emissions of all the heating options, a ground source heat pump (GSHP) system was the most effective method for this building.
As a result, a GSHP was installed to provide heating for the entire building. This included a closed loop collector system with 21 boreholes each 170 metres deep. Together, they can deliver 425 megawatt hours (MWh) of renewable heating annually.
In addition to this, we also carried out extensive thermal analysis to optimise the fabric upgrades while respecting the sensitive nature of the existing façades. This has led to a 40 per cent thermal performance improvement.
An award-winning model of sustainable conservation
In addition to the provision of new rooms, apartments and research facilities for students and staff, the deep energy retrofit has transformed the Rubrics building into a model of sustainable conservation.
The new geothermal system provides 100 per cent of the building’s heating and is expected to reduce primary energy use and CO2 emissions from the refurbished building by 75 per cent compared to previous levels, setting a new standard for energy-efficient retrofits in heritage structures.
The heat pumps also use waste heat recovery to generate domestic hot water for most of the year, meeting 80 per cent of the building’s hot water needs.
Already, the Rubrics has earned prestigious recognition. At the AUDE Awards 2023, it was commended in the University Impact Initiative of the Year category and won the Retrofit of a Building award at the Towards Net Zero Awards 2023.
Speaking of the project’s success, Trinity College Bursar Eleanor Denny said: “The Rubrics is a true landmark on Trinity’s campus. What has been achieved with this beautiful building – in preserving its historic nature while ensuring it can meet modern energy standards – is extraordinarily exciting. This project will be a pathfinder for future projects involving our heritage estates.”