by: Anita Derjanecz, REHVA Managing Director - Francesco Mariottini, REHVA Assistant Project Engineer
Quality management and building commissioning are key tools in closing the gap between designed and actual energy performance of buildings. Continuous commissioning and technical monitoring through the building life cycle can ensure that buildings reach, and maintain the intended performance levels. However, the building commissioning process is often not properly implemented despite the benefits of this approach. This article summarises the concept, existing initiatives and evidence, initiatives and projects demonstrating the benefits of quality management in buildings.
How the commissioning process and the quality of buildings are interlinked
Building owners, investors and housing providers realise more and more that the increased technical complexity of buildings makes it necessary to actively monitor and verify the quality of any building work to make sure that the required performances they paid for are achieved. Many problems that arise with buildings’ energy performance, and comfort are not caused by inappropriate technology and lack of conceptual intelligence but by absence of technical monitoring and quality management throughout the building life cycle that affects the actual building performance.
The building commission process is a quality-focused procedure to enhance the delivery of a construction project. It includes commissioning process activities specified by the owner or required by a code or standard. This process focuses on verifying and documenting that all the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner’s requirements. Quality is measured by the level of compliance with predefined standards and other recommendations (i.e., design specifications in building projects). As an example, the specific fan power of an air-handling unit is of high quality if the measured Specific Fan Power during operation reaches the corresponding design value for this system as defined in the requirements.
State-Of-The-Art of Commissioning and Quality Management
Commissioning is an essential part of the core building life-cycle (from design to management), but it is often not carried out properly in Europe and control mechanisms are often not in place.
According to 'The Future of Building Optimization & Commissioning Services: Market Drivers, Barriers & Trends', northern countries (e.g., Norway, Sweden, Finland, and the Netherlands) commonly use stricter rules for commissioning. In other European countries, national guidelines and standards on commissioning and quality management are available, such as in:
- Austria: Guidebook on sustainable facility management
- Denmark: Official commissioning standard and Værdibygs guideline (Contributes to quality management by describing the time needed for commissioning and the economic benefits of proper implementation; provides templates and check lists to complete)
- Germany: Standard on commissioning of hot domestic water systems. Also VDI 6039 (Managing of Building Commissioning)
- UK: British standard 7000-4:2013 and CIBSE Commissioning Codes, (UK).
These guides and standards are based on Annex 40 and Annex 47 of the Energy in Buildings and Communities Programme (IEA-EBC) of the International Energy Agency.
The importance of commissioning is also highlighted by voluntary building certification schemes (e.g., LEED and BREEAM), which reward commissioning with a higher rating. In the case of LEED, commissioning is documented (and eventually managed) but additional quality management aspects (e.g., balancing) are not explicitly required.
In the USA, ASHRAE publishes standards and guidelines, and the Building Commissioning Association provides publicly-available documents such as best practices about commissioning for new and existing buildings.
In India, ISHRAE, the Indian Society of Heating, Refrigerating and Air Conditioning Engineers, and REHVA have developed a joint HVAC system commissioning guidebook that will be soon released by ISHRAE online
Guaranteeing quality by continuous commissioning and operational data monitoring – studies, good practices, and EU projects
Nowadays, building systems can provide an enormous amount of data on building operations. This extends the range of possibilities within the commissioning process, also allowing continuous commissioning, defined as an ongoing post-occupancy monitoring and assessment to verify whether the building services perform as expected in terms of comfort and energy efficiency of cost-effectiveness.
Research has highlighted that with continuous commissioning, energy savings slightly increase over time, because additional improvements (e.g., training, permanent metering, and feedback systems) help increase savings. This shows the importance of benchmarking performance over time and of revisiting the need to commission with some frequency. According to a study conducted in the United States, continuous commissioning can result in 16% energy savings on average in existing buildings and 13% in new construction, with a payback time of 1.1 years and 4.2 years respectively, while more than a quarter of the studied buildings saved more that 30% energy.
Quality management throughout the whole construction process is increasingly requested in the UK following the “Soft Landings” approach promoted by the UK Government. The Soft Landings programme established requirements for post-occupancy evaluation for centrally-procured public projects in the UK, requiring designers and constructors to stay involved with buildings beyond practical completion.
The QUANTUM H2020 project promotes a similar approach and aims to develop online tools and business models that support quality management through the whole building life to ensure proper building performance. Three ICT tools will be demonstrated and adapted by the project that was presented at a workshop during the REHVA World Congress CLIMA 2016 in Aalborg.
Quality management process through the building life cycle. Source: QUANTUM project
QUANTUM’s core concept, the “design for testability” requires the definition of transparent performance targets as a prerequisite for quality management, and provides cost-effective testing methodologies to monitor and verify whether the set targets are met. Testing and controlling deviations between the predefined requirements and the outcomes through the whole construction process ensure quality and deliver the expected performance. The importance of quality linked to building commissioning was also presented on the BUILD UP webinar 'Quality management within building commissioning'.
Guidance on continuous commissioning, and quality management for building owners and investors – the German case
Commissioning can support both risk mitigation and management (e.g., by assessing uncertainties about building performances), if available data are systematically recorded and processed throughout the decision-making process.
Building owners and investors usually lack basic knowledge about how to request commissioning and quality management services, how to organise the process in the pre-design, design, construction and operations phases, or how to define the responsibilities and draft the technical content of their documentation demanding for offers.
The discussions at the initial QUANTUM workshop highlighted the need for guidance to building owners to explain the importance of quality management, and to provide them with hands-on guidelines. QUANTUM has developed such a guidance document for public authorities that was published as official guideline by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety in in August 2017. AMEV (German Research Group for Mechanical and Electrical Technology, National and Communal Administration) prepared these guidelines in close cooperation with the QUANTUM partners and coordinator in Germany. The guideline on "Technical monitoring as an instrument for quality assurance of building technology" is available in German online and will be released in English as a QUANTUM guide in early 2018.
Quality management during the building life cycle can close the gap between designed and actual performance in buildings, and continuous monitoring can result in higher energy savings during operation. The performance gap is often linked to quality gaps and errors that occur between the design, construction, and operation phases. Continuous commissioning and technical monitoring are key tools to avoid, identify and fix quality problems and achieve the intended performance.
Existing standards and legislation for building and construction focus on specific technical problems while quality management is not tackled or has a secondary role. Building owners and operators overlook quality management, therefore there is a need for guidance on the technical monitoring and awareness raising among building owners and investors.
The H2020 QUANTUM project develops cost-effective online tools to perform technical monitoring, as well as guidance for building owners and investors, which explain the process and provide them with templates that can be used in tendering documentations and contracts.