What is a BMS Engineer?

Written by HVAC Guy

This blog will give you an honest insight into the day-to-day process of being a BMS Engineer. I will be talking about all different aspects of the job from software strategy planning to on-site hiccups and frustrations.

17 July 2021

This is the first question I get asked when I tell most people about my career. The fact is that most people have never heard of the trade and do not even know that people are out there doing what I do.

BMS Engineers are responsible for designing, installing and commissioning a system to efficiently control the built environment. You will find Building Management Systems in all sorts of buildings from small domestic dwellings to large multi-storey office blocks. Each system is individually tailored to the project and commissioned to suit.

There are many different titles used for the same job. Some of the titles are; Building Controls Engineer, Building Energy Management Systems Engineer, Automatic Controls Engineer to name a few.

Engineers usually come to the trade from other related disciplines such as commercial electricians or heating engineers. This is because a lot of the time the information overlaps. As a BMS Engineer you need to have a good understand of pretty much everything building plant related such as: refrigeration cycles, boiler plant, valve sizing and much more.

Typical tasks for the Building Management Systems Engineer:

Control panel design

Most Building Management Systems start on paper. Typically, new systems will be designed based off the architect’s drawings along with the mechanical consultants designs and specification. Often jobs which require a retrofit will be designed based off site surveys and existing documentation.

Once the information is available the BMS Engineer will look at what plant needs to be controlled and convert it all into points.

Now the points are known you can then select the control system to suit. There are various things to consider here, things that may be required in the specification which are non-negotiable such as communication protocols, Controller manufacturer, panel form factor etc.

Now all this is decided the control panel can start to take shape in the form of panel drawings. These drawings need to cover everything required to control the plant. Once designed it is common for the drawings to be sent to the Mechanical Consultant for approval before the panel is put into production.

https://bmsparts.co.uk – BCIA-Performance-Specification-for-BEMS

Document Production

A Building Management Systems Engineer will be responsible for providing an O&M package once the project is complete. This often includes a set of standard documents such as the following:

  • Points schedules
  • Equipment schedules
  • Control panel drawings
  • Description of operation
  • Site reports
  • Commissioning certificates

Most of these documents form the design of the BMS Control System. The documents will be referred to throughout the various project stages from ordering equipment to commissioning the system.

points sample
Drawing sample

Software Design

These days all modern BMS Control Systems are implemented electronically, gone are the days of the wall-mounted time clocks and optimisers.

A BMS Engineer will write bespoke software for each project. In some cases, the software logic can be cloned and applied to many different projects but it is very rare that you will get two identical jobs.

The software will often be created by using the project documentation already in place. The BMS Engineer will need to at least have a copy of the control panel drawings or the points schedule in order to create software to suit the design.

Software Design

Graphics Design

This often comes hand in hand with the software design, although depending on the project you may have a different engineer completing the graphics.

BMS software graphics are used to provide the end-user with an interface to control their system. These can be as simple, or as advanced as required. Modern Building Management Systems allow for the latest technologies to be applied when creating a user interface.

The engineer responsible for the graphic design will need to have a good understanding of the project to accurately replicate the system. They will also need to understand the Mechanical Consultants specification to ensure that they provide a system that complies.

Graphic Design Sample


Electrical Installation Checks

One of the first stages of the commissioning process is to check out the electrical installation. This is also part of the point-to-point checks which ensure that all items are terminated correctly at both the control panel and the field end.

The BMS Engineer is also required to make sure that the field devices are correctly installed, there is no point in having the sensor correctly connected if it is in the wrong location.

These types of checks are best carried out as soon as possible to catch and correct any required changes. BMS Engineers are often on-site quite late in terms of the project timeline, therefore it is important that any issues are spotted as soon as possible as to not delay the commissioning and therefore the handover of the project.

Mechanical Installation Checks

This is very similar to the electrical installation checks but arguably more important. The mechanical items can often be more involved and difficult to rectify.

During the pre-commissioning phase, the Building Management Systems Engineer will check that the mechanical items are correctly installed. This comes down to the BMS Engineers’ experience in most cases. Sometimes it is quite difficult to explain to experienced mechanical engineers that they have installed a valve backwords, or that they have mixed up the flow and return pipes. But it does happen, and it needs rectifying as soon as possible.

Site Surveys

Site surveys are conducted for a variety of reasons. It could be to determine what is on-site for future update works, it could be to offer energy saving advice, provide a maintenance quote, or many other reasons.

BMS Engineers are often well suited to carry out such surveys as they have a good understanding of control systems and the associated plant.

Report Writing

This is a key skill for the BMS Engineer. Each site visit should be signed off with a report to properly identify the work carried out along with any additional works that may be required.

Engineers report not only provide the customer with information about their site, but they also provide the company with a record of work carried out. This provides a bit of job history to the next engineer on-site so that no time is wasted going over old ground.


One of the most important tasks for a BMS Engineer. The commissioning stage of any project is key to ensuring a successful handover and continued efficient operation of the building.

The Building Management System Engineer needs to tie in with many other trades in order to successfully commission the control system. Obviously, this changes on a job-by-job basis, but at the very least there will be some tie-up with the mechanical engineers. On larger projects, you may need to commit several days if not weeks of time with other trades.

The first stage of any commissioning project is called the pre-commissioning stage. This is where point-to-point checks are carried out to ensure that all items of plant and field devices are terminated correctly. The field devices are also checked to ensure that they are installed correctly. Typically there is no need for the software to be installed for any of the pre-commissioning checks. At this stage, the plant may also be enabled in manual mode to make sure that the BMS is actually operating the required outputs.

Once all the pre-commissioning checks are carried out the laptop will come out of the bag and the building controller is powered up.

It is at this stage when the software will be installed. The BMS Engineer will then systematically go through the software to check that it is all configured correctly. Most of this testing will be carried out without operating any plant, this is to make sure that the software is correct, and no issues will be accidentally created because of faulty software.

Finally, the plant will be allowed to work through the BMS in automatic mode. The operation will be monitored and tested to ensure that everything is working as intended.

Handover / Demonstration

Often the final stages of the project are to demonstrate the system working and officially hand it over.

This varies from job to job, but it can involve a walk around the system, cause and effect witnessing, general operation tips, training on the front-end interface plus anything else which is deemed necessary for the end-user to operate the system.

Once this process is complete it is generally accepted that the BMS commissioning is now finished and the system can work automatically from now on.

Maintenance Work

A large part of the BMS industry falls under the maintenance and service sector, and for obvious reason. Whilst a BMS system is designed to operate autonomously it does require maintenance to ensure that all devices and controllers continue to operate in the desired way.

A Building Management Systems Engineer will carry out planned maintenance work to optimise and hopefully reduce the energy consumption of the building. The service work is also required to spot and rectify any potential issues before they create a problem for the end-user. This may be a problem for comfort, consumption, or both in some cases depending on the issue.

BMS Engineers carrying out service and maintenance work need to be organised and proactive. The engineer should ensure that all items are correctly checked and a detailed report is produced to provide the end-users with accurate information about the operation of the system.

Interested in becoming a BMS Engineer?

For those interested check out the BCIA website where you can book industry-approved training courses.

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