By James Walsh
After many years of lone voices championing the need to aim high and undertake deep retrofits, it has gained support at Government and Industry despite the many challenges. Like many aspects of society, there is scientific evidence, particularly in the Passive House field, of deep retrofits or EnerPHit achieving significant savings of 80% in carbon and energy demand. Sub-optimal renovation is worse than doing nothing according to Diana Ürge-Vorsatz. She refers to the “lock-in effect” as sub-optimal renovations are hard to revisit and energy saving reduction targets of 80% will be progressively harder to achieve over time.
How we recognise a deep retrofit is characterised by a whole-house approach with
- high levels of fabric insulation at wall, floor and roof
- high standards of airtightness
- thermally efficient triple glazed external windows and doors
- elimination and minimisation of thermal bridges
- mechanical ventilation with heat recovery installed to provide fresh air and recirculate heat within the building before the remaining stale air is extracted
This generally results in improved comfort for the occupants as well as substantially reducing carbon emissions and fuel bills.
Apart from the ‘kit’ of parts required, a key ingredient is the grey matter of the individuals who from inception to completion set the standard and work on the delivery and verification of the performance. The Deep could be characterised as
Dedication | putting in the time and resources required to get the various elements right rather than ‘it’ll do’ approach. |
Enthusiasm | a belief from all stakeholders that the goal of energy and carbon reduction is worth pursuing |
Education | we need to fully explain the objectives to all the participants from owner to all the trades. When they understand the ‘why’ they will take responsibility for their work contributing to the high standards asked for |
Performance | It’s not good enough to set out the standards, you need to inspect the work and verify the performance |
We were privileged for Dublin City Council’s first Passive house EnerPHit retrofit at St Bricin’s Park to have all these characteristics. EnerPHit is the most comprehensive deep retrofit certification system in Europe with a history of delivery.
Dedication assisted in overcoming issues such as thermal bridging and ventilation ducting to an existing building. An enthusiastic housing client and Cecilia Naughton of the City Architects Department supported high standards to improve the thermal comfort of residents and address fuel poverty in a substantial manner.
As well as education undertaken on the design side, the contractors team undertook on-site training with Tomás O’Leary of the Passive House Academy assisted by a series of industry trades in external wall insulation, airtightness, ventilation and heat recovery providing a comprehensive overview, sharing knowledge generously with good humour.
The project delivered new build standards of airtightness with an equivalent air leakage smaller than a business card for each dwelling. A 91% increase in fabric performance was accompanied by an 80% reduction on energy demand and CO2 emissions from the base case.
The outcome, improved thermal comfort and air quality contributing to the health and wellbeing of residents.
Heads up from IGBC:
Did you know that IGBC and NUI Galway are working on a digital retrofit platform funded by the EU H2020 project Turnkey Retrofit which aims to provide information about all things retrofit and a tailor made menu for the homeowner. The first prototype will be ready in October 2021. Email [email protected] for more information.
Want to know more about Renovation and Deep Retrofit? Discover our resources on the Learning Hub
James Walsh is a registered Architect based in Castleknock Dublin, trading as Low Energy Design. Since 2010 the practice strives to design buildings that delight the owners and deliver high performance in energy efficiency, comfort and reduced energy bills. James is a member of the Passive House Association of Ireland, Association for Environment Conscious Building as well as being a member of the RIAI and an NSAI registered Thermal Modeller.
Low Energy Design have designed numerous deep retrofit residential projects with the highlight, St. Bricin’s Park, Dublin 7 for Dublin City Council in 2019. This is a multi-award winning social housing retrofit project delivered to the Passivhaus EnerPHit standard. Among the honours, Low Energy Design won the design prize for Excellence in Residential Renovation at the Isover Awards 2019.