Last edited 17 Mar 2019

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Mind the (Performance) Gap

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This article originally appeared in CIAT’s Architectural Technology Journal, Issue 127, published in Autumn 2018. It was written by Erin O’Kane, Ulster University, author of a report that was awarded the 2018 CIAT student award for excellence in architectural technology (report). The report highlights the performance gap from a Northern Ireland perspective.

On-site verification, BIM, digital technologies, building performance – these are all terms that raise interest and sometimes even red flags within the construction industry today. Over recent years not only has the demand for low-energy buildings increased but also the drive to improve the image of the construction sector, not just in Northern Ireland, but globally.

This has become a hugely important factor, especially in relation to building performance. Potential clients and homeowners are becoming better informed and aware of new and improved energy efficiency measures. Low-energy design calls for a reconsideration of how buildings are designed and constructed, with materials and detailing being a key part of the process.

A performance gap has been identified between the predicted performance of buildings at the design stages and how they actually perform once construction has been completed. This is an area which requires urgent consideration and attention, to ensure clients are getting the standard of building they pay for and that carbon emission targets are achieved.

With the building regulatory process lacking necessary rigidity, due to the inadequate nature of periodic inspections, this creates a difficult yet critical area of the construction industry.

Problems can occur for a number of reasons, including; poor workmanship and on-site practice, substitution of materials from those originally specified, a lack of inspection and validation, contractors not fully understanding the importance of details or being unaware of updates or changes to legislation. Due to familiarity, some building contractors will want to construct certain details in the same way as they have done on previous projects, and there is always the possibility of poor site conditions meaning that important details are not constructed as intended.

The report highlights the performance gap from a Northern Ireland perspective, investigating issues to do with low energy design via a case study methodology. The study identifies issues in relation to on-site practice, verification and lack of communication between design team members before investigating how technological advancements and BIM processes can potentially assist.

The building design process has evolved to become more focused on science and materials, however the principle of separation between design and construction still very much exists. When a particular design reaches construction stage the inspection visits are intermittent and only at specific phases of the project. It is impossible to assess all aspects of on-site construction compliance as some of the work will inevitably be covered up by the time the visits happen. This is a common problem.

Whilst in some instances the changes made on-site may still achieve compliance, in others, changes to the approved designs or details could have a negative impact on the performance of the building in terms of its energy efficiency and performance in relation to fire. Taking the worst-case scenario, such practice could potentially have a catastrophic effect on safety, endangering lives. This is the scale of importance the report conveys.

Whilst the actual legislation, in terms of required outcomes, and the approved technical guidance documents would generally appear fit-for-purpose, there is a lack of a standardised and robust methodology to ensure compliance and consequently building performance. If higher-performing buildings are to become the norm this needs to change, advancing more intelligent design, regulatory and validation processes.

This creates an opportunity to be rectified through the use of a technology driven solution. There are many BIM related technologies which could be used to aid this, each with their own strengths and benefits, and these are merely a fraction of the technologies available which could be used in closing the performance gap. As knowledge and understanding of BIM processes has advanced, the wider benefits created by such new technologies and approaches to building design and management are beginning to be realised.

The allegations against current standards of on-site verification have been validated recently in the UK by publications of both the Independent Review of Building Regulations and Fire Safety Interim Report in the aftermath of the Grenfell fire tragedy (HMSO, 2017) and the Independent Inquiry into the Construction of Edinburgh Schools (City of Edinburgh Council, 2017). These publications highlighted issues within current regulatory processes and quality assurance respectively.

The report concludes by proposing a scaffolding approach which could allow for a more robust design and inspection system, potentially closing the performance gap.


The report, by Erin O’Kane, Ulster University, was awarded the 2018 CIAT student award for excellence in architectural technology (report).

This article originally appeared in CIAT’s Architectural Technology Journal, Issue 127, published in Autumn 2018. It was written by Erin O’Kane, Ulster University.

--CIAT

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