Last edited 17 May 2021

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BSRIA Institute / association Website

Building services maintenance contractors’ role in reducing carbon emissions

This article originally appeared as a BSRIA blog post Building services maintenance contractors have a key role in reducing carbon emissions from our existing building stock, published in December 2014. It was written by Mitch Layng, M&G Real Estate, Associate Director: Portfolio Energy Management.

This is an area that if not managed correctly will have a dramatic effect on energy consumption.

The UK has a target of an 80% reduction in greenhouse gas emissions by 2050, and this target cannot be achieved without reducing our energy consumption in our existing non domestic buildings. These 1.8 million buildings account for 18% of the UK’s total carbon emissions, with a consumption of 300TWh.

In addition to regulatory requirements that are in place to assist in the operational performance of buildings, such as building log books, metering strategy, air conditioning inspections, DECs (Display Energy Certificates) for public buildings, ESOS (Energy Savings Opportunity Scheme), to name a few, there are many standards and good practice guides from recognised and respected bodies available to the industry to help in optimising energy performance.

However, even where these are put into practice properly, the actual performance really comes down to the operational staff in control of the building and the services, and at a more granular level, depends on the competence and performance of the maintenance engineers.

There are two key elements that need to be considered when agreeing maintenance contracts; understanding the design intent of the building services, and ensuring the clients’ needs and business operations are clearly understood and a suitable maintenance regime is put in place.

It is challenging enough to ensure, even with a new building, that the design intent is transferred across to actual operation, let alone in a building that has services twenty plus years old with little or no information available, and that may have had scores of different tenants and many different maintenance contractors. Studies have shown the performance gap between design and operation exists in part due to a lack of understanding by the operational staff of how the building should operate, and the fact that the process involving the design, commissioning and handover does not involve the maintenance contractor. If the industry struggles to get a new building to operate as it should, even when processes such as TM54 (Evaluating Operational Energy Performance of Buildings at the Design Stage) and Soft Landings are included, what chance do we have with older buildings?

Operational responsibility for many commercial buildings is often outsourced to maintenance contractors through contracts that vary in detail from a simple proposal letter from a contractor, to complicated and detailed maintenance bespoke contracts. It is therefore common to find that standards vary, and client requirements are often not met, even with the most basic contracts and uncomplicated buildings.

There are a few important elements that should be considered and implemented. In order to understand how a building should operate, information is crucial, and it is important to gather all relevant information related to the operation, such as O&Ms (Operation and Maintenance Manual), log books, asset lists. It is unlikely that the original design information will be available, and so, depending on the size and complexity of the building it is worth considering using a specialist to survey and report on the design. However this can be cost restrictive and many clients rely on the maintenance contractor’s advice and expertise.

Careful consideration should be given to the maintenance strategy and the standards employed. The industry has carried out a lot of good work around maintenance management and standards. The CIBSE Maintenance guide M is an essential read, and the SFG20 specification (library of maintenance specifications for building engineering services) provides useful information when considering a planned preventative maintenance regime.

The importance of good maintenance cannot be underestimated when it comes to ensuring energy consumption is optimised, and so implementing a standard such as this is an important first step. However, using SFG20 alone can lead to vital areas of good housekeeping being missed.

This area often falls between two stalls, and ends up being forgotten. For example, although annual checks are included in SFG20, more regular checks of time clocks and settings is good practice. It is so easy to change a time setting for operation over a particular weekend, and then to forget to change back. This can, and does, result in significant energy consumption which could have been avoided.

Maintenance contracts that include an incentive to improve energy performance are becoming more popular, and are likely to become even more so in the future. These can include condition based monitoring and maintenance, and can be structured to ensure both client and contractor benefit. However, many maintenance contracts are fairly short term, which does not allow enough time for a return on investment. In general, longer term contracts, with elements built in to ensure value for money on a periodic basis, are more suited to ensure optimum energy performance. In the private sector, three year contracts are very typical, this is something that needs to be addressed if we want to make a significant impact.

How do you ensure the planned activities are being undertaken? This can be difficult, particularly in a large and complicated building. Even where a process exists that includes detailed SLA’s (Service Level Agreements) and KPI’s (Key Performance Indicators), it is not unusual to find deficiencies in maintenance. There are various reasons for this, some client driven, and some related to contractor management issues. Very often maintenance activities are reactive, and not planned to reduce reactive call outs, and the number of call outs can sometimes result in planned tasks being put back or not undertaken at all. Maintenance audits can often pay for themselves through identification of deficiencies, through energy savings and possible refunds in the short term, and equipment life in the longer term.

Although lack of maintenance on most of the services in a building have can have an effect on energy efficiency, (examples such as poor water quality, scale build up, bacteria, blocked filters etc., will all have a significant effect), the brains of most buildings is the building management system (BMS), and it is the lack of understanding and continual checking of this system that can cause the majority of problems, not only from an energy efficiency perspective, but also occupant satisfaction.

It is common for the BMS maintenance to be sub-contracted to a specialist provider, which adds another layer of management and complexity to the system. Over complicated systems, lack of proper commissioning and regular building changes often lead to BMS systems that are not understood by the operational staff, and result in inefficient operation. The consequences can be dramatic, even a simple BMS strategy error or a set point that is not correct can result in major plant and equipment being brought on at times when not required, without anyone knowing. Even if the BMS is showing on screen that an item of equipment is not running twenty four hours when not required, a programming error can lead to the equipment actually running, and without physically checking (or separately sub metering), it is difficult to establish actual operation.

So, despite well-meaning regulations, standards and good practice guides, of the biggest challenges is to ensure the correct maintenance regime is put in place to suit the needs of the end user, that the correct level of service is actually provided and maintenance tasks are undertaken. Regular reviews and checks should be carried out to ensure not only the maintenance regime is appropriate, but also that time settings and set points are accurate to match the needs of the occupants and building.

Both client and maintenance contractor have a responsibility to ensure this happens, a good working relationship is essential, and longer-term contracts with incentives built in will definitely assist in achieving significant savings at no or low cost. Savings of 10% should easily be achievable in most typical non-domestic buildings, with savings of 20% being in reach for some buildings. These are instant savings, and if applied across all non-domestic buildings, would potentially save 45TWh, a significant proportion of the UK’s targeted carbon emission reduction.


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