Design considerations for PC based access control systems

Many businesses have complex building layouts, often due to the industry they operate in or expansion of the premises following the growth of the business. This can often span multiple sites, sometimes across the globe, with each site accommodating a different mix of employees and visitors to manage. 

Some more extensive facilities can be responsible for managing the movements of thousands of people coming on and off-site every day, which quickly becomes a problem without a suitable system in place. Often, access control needs will extend further than the physical building itself, for example, car parking areas. This will typically be designed slightly differently for visitors and employees, often integrating a door entry (intercom) system into their access control to authorise visitors' access.

With all this in mind, security can quickly become a challenge as concerns exceed the limitations of many traditional alarm systems that can simply raise the alarm in the event of a security breach. CCTV cameras can be a useful additional measure but unless they are used alongside comprehensive access and security systems, can only record an event after the damage occurred.

A more comprehensive approach to security is required to minimise the risk rather than rectify a problem later. This is where we start to look at interweaving multiple systems into a single solution that meets the end-users' needs.

When designing and implementing an access control system, a process needs to be in place, guided by the requirements of the site, system and end-user. 

Most importantly, the first thing you will need to do is take an accurate site survey covering the points laid out below. This list is not exhaustive, and you may find additional questions necessary for specific sites.

What is the size and layout of the building?

  • The number of internal and external entry and exit points to be protected.
  • Any particularly vulnerable areas need to be noted.
  • It may be helpful to request site drawings to indicate potential install points.

How many users are on-site?

  • Employees and visitors need to be considered.
  • Allow for growth to ensure the system is not outgrown by the facility.

Consider the security level required

  • A financial or defence site, for example, is likely to require higher security
  • In some situations, higher security can be limited to certain areas

How does the user wish to manage the site?

  • Managing the premises remotely from the cloud could be a good option for extensive facilities or businesses with multiple sites
  • A smaller site with a centralised admin pc may find it suitable to manage from site

Consider complexity vs cost and the budget in place for the system

  • Unless the site requires high security, many advanced features may be an unnecessary cost
  • Higher security credential readers will increase the costs involved

Are there any specialist requirements?

  • Sometimes elevator control is integrated into the access control system with users being granted access only to floors they are authorised to visit.
  • Access controlled lockers are growing in popularity with the user only allowed access to their specified locker.

What type of doors and entry points are on site?

  • What is the construction of the doors and how are they situated? The answer to these questions will allow you to decide on an appropriate electric locking device to suit both the end-users needs and the door install requirements.
  • Turnstiles are another commonly found entry point that require a slightly different approach when integrating them into an access control system.
  • Car park barriers can require varying allowances when designing your system. You may decide to use a long-range proximity reader, a transmitter and receiver, or a door entry system integrated into the access control system. There are many possibilities worth considering.

Consider how you will site the door control units.

  • Some larger businesses will have a centralised comms room that will house all of the door control units. This will allow you to utilise a network switch and simplify the cabling requirements.
  • Often smaller installations will involve positioning the door control unit on the secure side of the door itself. Typically this can be above a suspended ceiling or mounted on the wall near the door.
  • Buildings with multiple doors in close proximity to each other but no comms room could benefit from using 2 or 4 door controllers. (door control units that have the capacity for more than one door on the access control board, running from one PSU)

How does the end-user plan to verify access credentials?

  • Biometric identification offers a higher level of security and removes the risk of the user not carrying their credentials. Environmental factors must be considered when planning to install a biometric reader
  • Proximity or swipe cards can also carry photographic identification as a further means of security
  • Proximity fobs or cards are easily accommodated by the user
  • A keypad allows for no credential to be held but does offer lower security

How will egress be managed at each entry point?

  • Is managed egress required using a second reader on the internal side of the door
  • Free exit through the use of an exit button
  • Sensor to automatically release the door

What is the staff turnover and how frequently are visitors accommodated

  • If the staff turnover is high, cards and fobs could be a costly consumable
  • Numbers on a keypad will quickly wear with high usage unless the code is changed regularly

Assess any emergency evacuation routes through the building

  • Emergency exit doors may need to utilise panic hardware, a "door open" alarm or other specific measures.

Where are fire doors situated?

  • If you are looking to apply access control to a fire door, there are many more considerations that must be noted such as fire-rated hardware and ensuring an install doesn't compromise the integrity of the fire door. We will not delve further into fire regulations, but it is imperative that you familiarise yourself with appropriate legislation when working with fire doors.

Other system integrations

  • What other security, surveillance or building management systems are existing that the access control will need to integrate with?
  • Will the same access credential be utilised for all systems? For example, Mifare format will allow for multiple uses such as the access control system and also cashless vending.
You can find out about the range of Access Control solutions available from CMW by clicking here. You can also speak to our access control specialist Emma Harris by emailing