Best practices for mixed-use buildings: Automation and controls

Taking on a mixed-use structure—such as one that includes retail and residential portions—can be an engineering challenge. With all the different engineered systems involved, it can be like working on and integrating several different projects at once. Building automation systems (BAS) and controls must be carefully integrated.

By Consulting-Specifying Engineer September 29, 2014


  • Anil Ahuja, PE, RCDD, LEED BD+C, CxA, President, CCJM Engineers Ltd. Chicago
  • Jason R. Gerke, PE, CxA, LEED AP BD+C, Mechanical and Plumbing Team Leader, GRAEF, Milwaukee
  • Keith Lane, PE, RCDD, NTS, RTPM, LC, LEED AP BD+C, President/CEO, Lane Coburn & Associates, Bothell, Wash. 
  • Brian A. McLaughlin, PE, Associate, Arup, Los Angeles

CSE: When designing integration monitoring and control systems, what factors do you consider?

Gerke: One thing we will typically consider is how systems will be integrated. The systems considered for this analysis include power and lighting, and HVAC controls in occupied/unoccupied spaces, back of house, utility rooms, parking garages, and other special spaces. Then a decision is required if these services will be integrated for full control, scheduling, or just monitored. Usually the driving factor for these decisions is cost. However, there are many owners interested in how these decisions will help them save money on future maintenance. This decision requires the input of the mechanical and electrical engineers in discussions with the owner to explain the benefits and complications that may be experienced with these choices. An e-mail stating it will probably cost “this much” will always generate a no-go request.
Ahuja: Some factors to be considered are: What is the current system, and what vintage is that system? What is the tenant/client’s goal in automation? Are existing systems going to be modified in the next year? Five years? Ten years? What is the client’s phasing plan in regard to existing equipment? How conscious is building management of green practices and energy management? Another big factor is whether the maintenance staff is on-site, or if it is a for-hire firm that will be monitoring and working remotely. This is becoming far more common in the industry to help reduce costs of on-site staff. 
CSE: What are some common problems you encounter when working on building automation systems (BAS)?
Ahuja: In many cases, the biggest problem is user interface, and lack of knowledge in regard to the system. Many engineers and maintenance staff have no working knowledge of the system, make changes without understanding the system effects, and eventually override the system manually because they cannot undo or do not understand the modifications that have been made. In many instances, changes in personnel also lead to issues because changes made by previous staff are not relayed to current staff. 
Gerke: “Problems,” while not really a negative issue, but more of a challenge related to automation systems, must be identified early in the design process. Typically, items to consider include: 
  • Is this a renovation with an existing system that works?
  • Does the system not work?
  • Could the system be extended/integrated into the new equipment? 
  • How much controllability is actually required? 
  • Is equipment monitoring enough? 
  • Will local electric/electronic controls be enough?
CSE: What types of cutting-edge control systems have you specified into these buildings? What type of pushback are you receiving from the contractors, clients, or other team members?
Gerke: While not cutting-edge, wireless sensors, thermostats, and equipment control connectivity are great ways to save labor on installation. There are concerns from some owners’ IT staff, interference from adjacent building occupancies, or influences on wireless connections from surrounding buildings.
Ahuja: Wireless technologies are advancing and provide flexibility and adjustability features not available in old wired technology. For example, moving a thermostat’s location due to change of use or because the sun is hitting the thermostat and not allowing the HVAC system to maintain space comfort is much easier with wireless technologies. Integration of lighting, HVAC, and security is also desirable. Due to the breakdown in trades, sometime this is the most difficult to achieve. The biggest challenge remains integration of all systems in building on one platform.