Guide to Access Control Design (Jan 2020)
January 13, 2020
Effective access control design is a real art. Without it, the installed access system will forever be problematic and you will be plagued by an unhappy client or user. Poorly designed systems require constant maintenance and often break-down leading to security vulnerabilities at a site.
After the security survey has been conducted and the appropriate mitigation measures chosen by the consultant and/or client, the access control design process starts. The following is a helpful guide of items to be taken into consideration at the design stage of the access control project or installation:
1. Simulate the Access Control Flow for the Site @ the Design Stage
Nothing works better than simulating the day to day operation of the access control system prior to the project or actual installation.
- Often practical design issues can be picked up at an early stage or additional doors/areas which require access control are picked up and can then be planned or budgeted for.
- Scenarios should be planned for, including how visitors will enter or exit the site (visitor management), how contractors will enter or exit the site and how the system will work during operational hours and after hours.
- A useful exercise is to create an access control flow diagram similar to the one above. This should include doors, vehicle barriers (if applicable), turnstiles, fire escape routes, guard points, high-value assets and other areas requiring physical access control.
- Meetings should also be held with all project stakeholders to understand how the site will operate and to go through operational scenarios.
- Lastly, the rational fire design/safety plan for the building should be reviewed in conjunction with the access control design to ensure the access control system will be able to comply with the access or emergency egress requirements.
2. Choose the Appropriate Access Control Credential for the Application:
Access/Control credentials exist in many formats. These include fingerprint biometric or facial recognition templates, wireless keyfobs, proximity RFID tag/cards, numberplate recognition camera templates, long-range RFID tags, one-time-pins and even new generation QR code access credentials.
- The client or consultant need to choose a credential best suited for the particular access control point / ‘door’ as well as for the throughput and security level required.
- Some access/control readers such as fingerprint biometric readers have a longer ‘processing’ time than a traditional proximity swipe card reader. Thus as an example for a site with a large number of tenants entering or exiting through a turnstile at key times, fingerprint readers may become an irritation. They could cause ‘bottle-necks’ and delay access into or out of the building.
- Here proximity cards/tags would be the fastest credential method. Some new generation facial recognition readers are also effective but there is the processing time and/or the additional delay of the reader not recognising the person.
- Other sites may have certain higher security doors such as server rooms which will have a smaller much slower traffic footfall but will require higher security credentials or a combination of credentials (such as pin & card). For such applications, biometric fingerprint readers would be well suited.
- For residential vehicle access control by authorised tenants, the faster the access/control method the better. The tenant is a target when they arrive or leave the site. In such scenarios typically wireless keyfobs, number plate recognition camera access/control, and long-range RFID readers with vehicle-mounted tags are good options. However, with some projects cost may be an issue and then a biometric or card/tag reader needs to be utilised installed on a gooseneck.
- The handling of visitors is obviously different to that of tenants and the processing of them is longer. Ideally, the site should make of a visitor registration system which can cater for pre-registered visitors/contractors or walk-in/adhoc visitors.
3. Prepare the Access Control Door and Door Frame:
The most important item to consider is to prepare the access control door and/or door frame for the lock prior to installation.
- With many installations, doors and/or door frames are only prepared at the construction stage or just before the final fixes are done on the project.
- This is too late and causes major problems as locks often need to be retrofitted or doors/frames ‘butchered’ onsite to cater for the striker, striker plate or the lock itself. Work should rather be planned and done carefully at the manufacturing stage.
- Ideally, actual samples should be provided to the door manufacturer for fitting at the factory or for making a template for manufacturing the doors/frames.
- Below is an example of an aluminium door which has been prepared at the factory and designed to fit a recess-mounted fail-safe magnetic door lock. The door has been problem-free since being installed five years ago.
- In terms of lock cabling, arrangements should also be made to reticulate the cable to the door (if applicable). This is the case with access/control installations where the ‘powered item’ is the electro-mechanical lock or striker lock on the door versus a situation where you have the ‘powered item’ on the door frame (such as with a maglock installation). Access control installations which typically have double-leaf doors setups will have the same requirement.
- Door cable loops are typically available as a hidden door loop which gets cut into the frame (at the manufacturing stage) as above or as a surface mount loop that is normally retrofitted to existing doors or when no design planning has occurred (as below:
4. Fit a Suitable Door Closer:
An item which is often forgotten in many projects is the humble door closer which is a valuable item to complete any access control door installation.
- At the design stage, it should be agreed who’s responsible for the supply and fitment of this item.
- Ideally whoever is fitting and supplying the ironmongery (such as door handles etc) at the site should also supply & fit the door closer/s.
- Some doors such as pivot doors or glass frameless doors may require floor mounted floor springs which act as door closers.
- For a door closer to work, the door should not be too heavy, should be able to close naturally without any great force and should not be encumbered by pressure or wind issues.
- In certain situations, a difference in pressure between two areas (such as inside and outside an access control door) can prevent a door from closing naturally. This can be rectified by installing a ventilation grille in the door (not ideal for security) or by changing the pressure in the room by some other means.
- Access control doors without door closers tend to be left open by users and/or slammed shut which causes damage to the door and/or lock.
5. Ensure Access Control Door locks are at the correct installed height:
Door locks fitted at incorrect heights lead to door buckling and maintenance issues.
- They also make the access control installation very weak as the door’s holding strength is unequal and centred in one uneven spot instead of being spread along the door.
- These doors are also normally easier to force open by an intruder. The door below is a prime example of this setup:
- Ideally, locks should be mounted mid-height on the door rather than at the top of the door, however, if surface mounted this may present a safety issue as an individual could injure themselves on the lock as it may protrude out into the doorway.
- For extra long doors, multiple locks should be considered or access control installed on an alternative door.
6. Avoid Unsafe Side Access Control Wiring:
In many installations, access control cabling is accessible from the unsafe side of the door. This is a major security vulnerability.
- A potential intruder could gain access to this cabling and open the door by cutting or damaging the cabling (with a fail-safe lock such as a maglock).
- The photo to the right and the photos below are good examples of where the wiring for the lock is accessible from the outside of the door (the unsafe side).
- A more effective design of the access control system could have prevented this.
- In such a scenario, the conduit for the lock should have been designed to be reticulated on the ‘safe’ side of the door.
7. Confirm Access Control Reader Heights
Ensure Readers are installed at the correct height and distance away from the user.
- This applies to proximity card readers, long-range RFID readers, biometric readers and especially numberplate recognition access control cameras. An incorrectly placed reader can cause years of frustration for the user with difficulty in using the reader and/or false or incorrect reads.
- Suitable planning should be made at vehicle entrances to accommodate different height vehicles such as sedans and SUVs. As an example, for vehicle entrances used by large trucks, a second reader would need to be fitted at a much higher height to accommodate these.
- For pedestrian entrances, design work should involve planning for allowing people with disabilities to use the reader and the door.
8. Consider Pedestrian Access Routes:
With many access control installations, no consideration is given in terms of planning for pedestrians to gain access into or out of the site. Often the overriding consideration goes to vehicle access.
- Planning for pedestrian access will help improve safety at the site and help increase security by creating dedicated ‘choke-points’ for individuals to gain access or to leave the site.
- A site where pedestrians are forced to use a vehicle lane as an access/control route is a health and safety risk for a site as a visitor and/or pedestrian is in danger of being hit by a vehicle.
- The other issue is that vehicle booms often end up being damaged as they are bumped or knocked every time the pedestrian passes by. There is also no physical barrier preventing random individuals from gaining access to the site when the security officers may be otherwise occupied.
- Ideally, a turnstile or a gate with access control should be fitted to channel and control pedestrian access into or out of a site.
9. Avoid Long Access Control Cable Runs:
Long cable runs cause voltage drops over distance. This can be problematic when equipment requires a certain voltage and it doesn’t receive it.
- Many intermittent access/control issues at a site are caused by this.
- If 12VDC magnetic door locks receive insufficient power they are often easy to push open which is a serious security vulnerability.
- Power supplies should be installed in central locations and consideration taken in terms of what type of cabling is used to carry power to equipment (gauge etc).
- It is critical that access control design work for any project should involve the careful planning of equipment locations, location of appropriate power points and cable routes.
10. Plan for the System's Power Requirement:
Access control systems should always be connected to dedicated power circuits and/or UPS power circuits.
- Systems connected to shared circuits are susceptible to power outages and power surges which affects the lifetime, operation and continued reliability of the access control system.
- These should also be protected from tampering or someone inadvertently switching them off.
- Power requirements and mains power point locations should be relayed to the project electrical engineer and/or the client at the design stage so that these can be catered for accordingly to avoid a scenario such as the one below.
- This should include the number of sockets required and the height at which these should be ideally mounted.
11. Use appropriately sized conduits and ensure sufficient wire-ways are installed:
Cable reticulation design is an essential component to any access control design.
- How often does one get to a building site to find that the electrical contractor has installed insufficient conduits to the door?
- As part of the design process, the electrical engineer or customer should be provided with a cable reticulation design drawing to ensure what is required for the installation is catered for. Poor or insufficient wire-ways lead to cable damage, ‘sharing of cable cores’ and problems when cabling need to be replaced at a later stage. A typical example of a site with problematic access control conduit is below.
- In addition, a door detail should also be provided so there is no confusion as to the layout at the actual door itself. An example of a door detail drawing can be found below.
12. Don't Forget the Life Safety System:
Most modern access control installations will require some interfacing to a life safety system such as a fire detection system. This is in order to accommodate a safe exit for the tenants and/or visitors at a site in the event of an emergency such as a fire.
- Consideration should be taken in terms of the installation of fire relays and/or other devices which will cut power to access/control doors or make them fail-safe in the event of a fire.
- This design work should be done in conjunction with the life-safety engineer and/or fire specialist on the project and should meet the applicable safety codes in that country and/or city.
13. Avoid using fire escape doors as access/control 'doors':
- Be cautious about using fire escape doors/gates as access control ‘doors’. The use of these doors for access/control should be avoided and dedicated fit for purpose access/control doors should be accommodated for by the building architect.
- Fire escape doors are normally supposed to be for minimal use such as exit in the event of an emergency, not for heavy-duty regular pedestrian use.
- The options in terms of electrical locking devices for these doors/gates is limited. As an example, one could fit a fire-escape compatible striker lock devices such as the unit in the first photo below, but from experience, these can easily be overcome by an intruder, require regular maintenance and end up being easily damaged due to constant use.
- In this case, after the building was handed over by the developer, the client replaced the lock with a non-fire escape door lock (as can be seen by the 2nd photo below).
- Wooden fire doors are also easily damaged and eventually become a maintenance nightmare for the facility management at the site. Door magnetic lock striker plates also eventually fall or are damaged due to regular use.
14. Design with tailgating in mind:
A very common issue in the security industry, this cannot be completely eradicated but there are some measures which can be implemented to reduce this.
- The installation of turnstiles is obviously the most obvious option, however, in many applications cost, space constraints or aesthetics may prohibit this.
- Other design ideas include the establishment of lift lobby access control doors versus elevator only access control. It is easier for someone to jump into an elevator versus forcing there way past a person who has just gone through an access door. From an operational point of view, tenants/staff in a building would need to be educated accordingly in this regard.
- Door prop alarms are also helpful as they sound after a door is ‘held-open’ after a preset time.
- Vehicle access/control tailgating is also a great danger as people do silly things to save a few bucks or get in or out of a site. Suitable planning needs to go into the design of the vehicle lane in relation to ground loop & sensor locations.
Conclusion & Summary
A properly designed access system will lead to a successful project which should be able to be delivered on budget and on time by the access/control integrator. It should also provide the developer, client or end-user with a reliable system that would require minimal maintenance moving forward.
Below is a summary list of the topics already discussed in the article above.
- Simulate the Access Control Flow for the Site @ the Design Stage
- Choose the Appropriate Access Control Credential for the Application
- Prepare the Access Control Door and Door Frame
- Fit a Suitable Door Closer
- Ensure Access Control Door locks are at the correct installed height:
- Avoid Unsafe Side Access Control Wiring
- Confirm Access Control Reader Heights
- Consider Pedestrian Access Routes
- Avoid Long Access Control Cable Runs
- Plan for the System’s Power Requirement
- Use appropriately sized conduits and ensure sufficient wire-ways are installed
- Don’t Forget the Life Safety System
- Avoid using fire escape doors as access/control ‘doors’
- Design with tailgating in mind