Updated May 2026. Written by the TEC Solutions team, a CyberLock integrator serving utilities, municipalities, and commercial facilities for over 20 years.
To install access control in an existing building, you choose between two paths: rip out your locks and run wire to every door, or retrofit the cylinders you already have. For most facilities, the retrofit path is faster, cheaper, and less disruptive. With an electronic key system like CyberLock, the existing lock body stays, the door stays, and a single cylinder swap turns every entry point into a logged, controllable access point. No drilling, no wiring, no downtime.
That’s the short answer. The rest of this post walks through what it takes to install access control in an existing building, how long the work takes, what it costs against traditional hardwired access control, and where retrofit is the right call versus where you need new hardware.
What does it mean to install access control in an existing building?
To install access control in an existing building means adding the ability to track, schedule, and revoke who can open which doors, without tearing the building apart to do it. Traditional hardwired access control replaces every lock with an electrified strike, runs cable from each door back to a centralized controller, and ties the controller into your network. A retrofit approach skips the cable and the controller entirely by putting the intelligence inside a battery-powered key and a self-contained electronic cylinder. The doors look the same. Only the cylinder changes.
For an older building with thick walls, multiple floors, remote outbuildings, or doors in environments where pulling cable is a project unto itself (think substations, water plant pump houses, roof equipment closets), the retrofit path is often the only path that finishes inside budget.
What are my retrofit options?
Two real options exist for adding access control to an existing building. The first is full hardwired access control, where each door gets an electric strike or maglock, a card reader, a request-to-exit sensor, a door position switch, and cable back to a controller. The second is an electronic key retrofit, where each existing mechanical cylinder is swapped for an electronic one that authenticates against a programmable key. Both produce an audit trail; only one of them requires opening walls.
| Factor | Hardwired access control | Electronic key retrofit (CyberLock) |
|---|---|---|
| Wiring required at the door | Yes (line and low-voltage) | No |
| Door modification | Often required (strike, frame) | None. Existing lock body stays |
| Installation time per door | Hours to days | Minutes |
| Phased rollout | Difficult after controllers are sized | Easy. Add doors as you go |
| Network connection at each door | Required | Not required. Locks are offline |
| Approximate installed cost | Baseline | Roughly one-tenth of hardwired (per TEC Solutions CyberLock product page) |
For a single high-traffic main entry with hundreds of daily users, hardwired with a card reader is usually the right answer. For everything else, the math leans heavily toward retrofit.
How long does it take to install access control in an existing building?
A typical CyberLock cylinder swap takes a few minutes per door. According to the TEC Solutions CyberLock product page, the system is designed for fast installation across many doors because there is no wiring to run and no door modification required. A facility manager can usually install access control on a small site of 10 to 20 doors in a single afternoon. A 100-door utility can be retrofit over a long weekend or rolled out in phases over a few weeks without disrupting operations.
Compare that to hardwired access control on the same door count, where each door involves an electrician, a low-voltage technician, network drops, controller programming, and inspection. A 100-door hardwired install is typically a multi-month project with extended downtime per door.
What does the install access control process look like, step by step?
For an electronic key retrofit, the work breaks down into five steps:
- Survey the doors. Document existing cylinder types (SFIC, mortise, rim, cam lock, padlock) so the right replacement format can be ordered. CyberLock offers over 430 retrofit cylinder designs that fit existing hardware.
- Order cylinders and keys. Cylinders are matched to your existing hardware. Keys are programmable, so the same key works across the entire system.
- Install the management software. CyberAudit-Web (the system’s management software) lives on a server or in the cloud. User accounts, schedules, and door groups are set up here before any cylinder goes in.
- Swap the cylinders. Each door takes a few minutes. The old mechanical cylinder comes out, the new electronic cylinder goes in. The door looks identical when it’s done.
- Program and deploy keys. Users come to a programming station or vault to receive their keys, which carry their permissions and expiration schedule. Lost or stolen keys can be revoked in software at any time.
The audit trail starts the moment the first cylinder is installed and the first key is used. Within the first week, you’ll have a complete record of who accessed which door and when.
Do I need to rewire my building or run cable to every door?
No, and this is the single biggest reason retrofit electronic key systems exist. The CyberLock cylinder is powered by the key at the moment of use, not by a battery in the lock or by line voltage. The cylinder is offline until a key touches it. That architecture means no cable from the door to a controller, no power supply at the door, no network drop, and no work above the ceiling. Per the TEC Solutions product page, this is the design choice that makes large-footprint deployments affordable.
For buildings under regulations like NERC CIP-006-6 for electric utilities or AWIA Section 2013 for water utilities, the audit trail data the system produces satisfies the physical-access documentation requirements without any new cabling on the asset itself.
Can I install access control in phases?
Yes, and you should. The retrofit model is built for phased rollout. Start with the 10 or 20 highest-risk doors, prove the audit trail with your security or compliance team, then expand to the rest of the facility on a schedule that works for your budget cycle. Cylinders can be moved or renamed in the management software as the deployment grows, so a door that was retrofit in Phase 1 can be reassigned, repurposed, or relocated without buying new hardware.
Phased rollout is much harder with hardwired access control. Once a controller is sized for a certain number of doors, adding more doors later often means adding more controllers, more cable runs, and more network capacity. You pay for that capacity up front whether you use it or not.
What does it cost to install access control vs. hardwired?
The hardware cost to install access control with an electronic cylinder is comparable to a high-end mechanical cylinder. CyberKeys and the CyberAudit-Web management software are additional. The big savings show up in what you don’t have to buy: per-door wiring, controllers, power supplies, network drops, and the labor to install all of it. According to the TEC Solutions CyberLock product page, total installed cost across a multi-door deployment is approximately one-tenth the cost of comparable hardwired access control.
The long-tail savings are even bigger. According to commercial locksmith pricing data aggregated by Fixr.com, rekeying a single commercial cylinder runs $50 to $150 per lock in 2025, and master-keyed cylinders cost $100 to $150 each on top of a $100 to $300 master pinning chart. A lost master key at a 50-door site is a $5,000 to $7,500 locksmith event with a mechanical system. With an electronic key system, that event is a software revocation. You never rekey again.
When is retrofit NOT the right answer?
A few situations call for hardwired access control instead of a retrofit:
- High-traffic public entries with hundreds or thousands of daily users where badge-tap convenience matters more than per-door audit detail. A card reader at the main lobby door is usually the right call. Retrofit electronic keys handle everything past that.
- Doors that require remote unlock for visitors, deliveries, or emergency response. An electronic key requires the key holder to be physically present. If you need a remote button to buzz someone in, you need a hardwired or networked solution at that specific door.
- Integration with existing badge or video systems where the customer has already invested heavily in a unified credential. A hybrid approach (card readers at staffed doors, electronic keys on everything else) is usually the smarter answer than ripping out the existing investment.
For most utility, telecom, water, healthcare, and municipal customers, the doors that need access control are doors with low entry volume per door spread across a lot of locations. That profile is exactly where retrofit electronic key systems excel.
How do I avoid downtime during installation?
Three practical moves keep operations running during a retrofit rollout:
Install during low-traffic windows. A few minutes per door is short enough that most cylinders can be swapped during scheduled maintenance or off-hours without affecting staff.
Keep the existing mechanical key in service until the cutover. Until you revoke the old key system, both paths work. You can run the building on dual access for as long as you need while the team gets used to the new keys.
Phase the rollout by area, not by door. Do an entire wing, building, or substation in one push rather than scattering individual doors across the facility. It keeps the audit trail clean and makes user training easier.
The bottom line on how to install access control in an existing building
If you need to install access control in an existing building, you don’t need to rip it apart. A retrofit electronic key system gives you the audit trail, the revocation, and the scheduling of hardwired access control at roughly one-tenth the installed cost, with installation timelines measured in minutes per door instead of hours. The lock body stays, the door stays, and your operation keeps running.
TEC Solutions has been providing custom access control and security solutions to utilities, municipalities, and commercial facilities for over 20 years. To see what it would look like to install access control at your specific site, contact us or call (888) 289-8911.
Frequently Asked Questions About Installing Access Control
What is an access control retrofit?
An access control retrofit is the process of adding electronic access control to an existing building by replacing the mechanical lock cylinders with electronic ones, instead of installing wired card readers and controllers at every door. The door, frame, and lock body stay; only the cylinder is swapped.
Can I install access control without running cable?
Yes. Electronic key systems like CyberLock do not require any wiring at the door. The cylinder is powered by the programmable key at the moment of use. There are no batteries in the lock, no network drops, and no controllers to install.
How long does it take to install access control in an existing building?
Each cylinder swap takes a few minutes. A 10 to 20 door site can typically be retrofit in a single afternoon. A 100-door deployment can be completed over a long weekend or rolled out in phases over a few weeks without disrupting operations.
What’s the cost difference between retrofit and hardwired access control?
According to the TEC Solutions CyberLock product page, a retrofit electronic key deployment can be installed at approximately one-tenth the cost of comparable hardwired access control. The savings come from eliminating per-door wiring, controllers, power supplies, and network drops.
Will electronic locks fit my existing doors?
In most cases, yes. CyberLock offers more than 430 retrofit cylinder formats that match standard commercial hardware including padlocks, cam locks, deadbolts, SFIC cores, and mortise cylinders. A site survey identifies the right cylinder for each door before installation begins.
Can I keep using my old mechanical keys during the transition?
Yes. Most retrofits run both systems in parallel until the cutover. The existing mechanical key continues to work for staff who haven’t received their electronic key yet, while the new system runs in pilot mode. Once the old key system is revoked, the building is fully on electronic access.
Do I need an electrician to install access control in an existing building?
No. Because there is no wiring at the door and no power supply to install, an electrician is not required for a CyberLock retrofit. A locksmith or facility technician can swap the cylinders. The management software setup is a separate IT-side task.