Publication
OPW Technical Guidance: ‘Approaches to Improving the Energy Performance of Heritage Properties in State Care’
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The Office of Public Works is responsible for managing the Government’s estate portfolio, including iconic heritage properties to the more every-day buildings for essential government and public services. The Governments Climate Action and Low Carbon Development Amendment Act 2021, the Annual Climate Action Plan (CAP), and the annually updated Public Sector Climate Action Mandate (Mandate) commit Ireland to a strategic direction to reducing greenhouse gas emissions by 51% by 2030 and achieving net-zero emissions by 2050.
With a significant holding of heritage properties and a commitment to improve energy efficiency across its portfolio, the Office of Public Works Heritage Services conservation architects identified a need for a detailed in-house technical guidance with a readily applicable and standardised process to apply to projects which would include energy efficiency improvements to heritage buildings.
The resulting new OPW technical guidance, ‘Approaches to Improving the Energy Performance of Heritage Properties in State Care’ provides a replicable methodology to assist with the assessment of existing building energy performance and the identification of energy efficiency improvement works that will provide the greatest energy efficiency benefits whilst respecting the heritage significance. This guidance document has been developed for use within the Office of Public Works.
The guidance follows the process recommended by I.S. EN 16883:2017 ‘Conservation of cultural heritage - Guidelines for improving the energy performance of historic buildings’ and provides practical advice on the steps necessary to arrive at rigorously assessed and suitable solutions tailored to each individual building and its particular requirements and constraints. This step-by-step process assists with the assessment of heritage value; identifying fabric / services upgrade opportunities and constraints; measuring and calculating existing thermal efficiency; analysing potential hygrothermal risks associated with different insulation options; determining appropriate energy renovation objectives and targets; designing appropriate fabric and services upgrade specifications to the historic building; and recommendations for post-occupancy evaluation and monitoring.
Office of Public Works architects department worked with Shaffrey Architects with support from Arup Engineers and Passivate Building Energy Consultants to develop the guidance and initial exemplar desk-top case-study No.7 Merrion Sq.
The OPW, as the Irish state’s main property portfolio manager and advisor, has adopted and will implement the guidance methodology in our approach to forthcoming energy efficiency upgrades of historic buildings. Notably, the recommendations for in-situ measurements, hygrothermal risk assessments and post-occupancy monitoring will inform a more data-driven approach to future heritage building energy renovations and will provide much needed data on the actual performance of energy renovation works.
The guidance will initially be supported by two case studies to demonstrate the recommended approach in practice; 1) a typical Georgian terrace at No. 7 Merrion Square, Dublin 2 and 2) a former army barracks at the ‘Block M’ Office, Ship Street, Dublin Castle, both in use as offices. Further case studies will be compiled and made available as subsequent energy renovation projects are completed.
As increased attention is placed on improving the energy efficiency of the worst performing buildings, many of which are believed to be traditionally-built, guidance was urgently needed to consolidate existing knowledge and experience into a holistic energy renovation methodology for OPW architects to assess and adapt heritage properties for improved energy performance. Whilst this guidance was written to assist OPW architects with the renovation of historic properties in state care, a decision has been made to share the guidance and case studies more widely to support broader public and private sector initiatives in meeting National and EU carbon emission reductions for the existing built environment, to build upon industry wide technical expertise and to reduce instances of maladaptation of historical structures in the name of energy efficiency.
