The keyed-both-sides design is a real category in door hardware, and electronic versions exist. What changes is how a door is used: anyone leaving through that door needs a key, a code, a card, or another approved method, and that single fact shapes where the lock belongs and where it does not.
What a double key deadbolt smart lock actually is
A double cylinder deadbolt has a key cylinder on the outside and a second key cylinder on the inside, instead of the usual thumb turn. A double key deadbolt smart lock adds electronic access on top of that arrangement, so entry can be granted by credential rather than by metal key alone.
The two halves of the name describe two different jobs. The deadbolt is the mechanical bolt that resists forced entry. The smart layer is the credential system that decides who gets in, when, and with what method. A keyed-both-sides deadbolt keeps the mechanical side strict, because the inside face cannot be turned by hand.
That combination is why the category sits awkwardly between two product families. A standard smart lock assumes the inside is free to operate. A double cylinder deadbolt assumes the inside is deliberately locked. Merging them means the electronic layer has to work around a mechanical rule that was never designed for convenience.
Why the inside cylinder changes everything
With a single cylinder deadbolt, a person inside can always open the door by turning the thumb turn. With a keyed-both-sides deadbolt, that same person needs a key or an approved credential. In a fire or a panic, that difference is the whole argument.
Electronic access can soften the problem but does not remove it. A keypad, card reader, or app-based unlock still depends on power, a working reader, and a credential that the person actually carries. If any of those fail at the wrong moment, the inside face is still a keyed cylinder.
Why keyed-both-sides deadbolts exist
The reason is glass. A door with a large glass panel, a sidelight, or a narrow frame can be broken, and a thief can then reach an inside thumb turn and open the door without ever picking the lock. Removing the thumb turn removes that route.
The same logic applies to doors with a nearby window, a mail slot, or any opening wide enough to reach through. The deadbolt is not made harder to pick; the easy path around it is closed.
That benefit comes with a cost that is easy to underestimate. Every legitimate user of that door now carries a key or a credential for the inside face as well. In a home, that means a key kept near the door for exit, which weakens the original idea. In a shop or office, it means staff need a credential to leave through that door during an emergency.
Where the trade-off lands
Keyed-both-sides hardware suits doors that are rarely used for normal movement and are secured for long periods. It fits poorly on a main entrance that a household or a team passes through many times a day.
That is the honest constraint. The lock solves a reach-through problem and creates an exit problem. Whether the exchange is worth it depends on how the door is used, not on how the lock is marketed.
Where a double key deadbolt smart lock fits in Malaysian homes and shops
In Malaysian terraced houses, shophouses, and converted commercial lots, doors often sit beside glass, grilles, or a narrow side panel. Those are the doors where a keyed-both-sides deadbolt earns its place, because the reach-through risk is real rather than theoretical.
Shops and offices with a back door that stays locked during trading hours are another reasonable fit. Staff use the front entrance, the back door stays secured, and the electronic layer records or restricts whoever is authorised to use it.
The fit is weaker on a main family entrance, a bedroom door, or any door that doubles as a fire escape route. A door that people must pass through quickly should not require a key or a working reader to open from the inside.
Homes
A home with a glass-panelled front door and a household that mostly uses a different entrance can use a keyed-both-sides deadbolt on the glass door. The smart layer then handles entry for family members and keeps a record of use.
A home where that same door is the everyday entrance runs into the exit problem daily. A key left in the inside cylinder solves the exit but reintroduces the reach-through risk the lock was chosen to remove.
Shops and offices
Commercial premises usually have more than one door, which makes the trade-off easier to manage. The keyed-both-sides deadbolt goes on the door that is not the primary escape route, and the electronic layer handles permissions for staff and after-hours access.
Eyonic's smart lock and access control work treats user permissions and backup entry as planning items rather than afterthoughts, and checks whether a standalone smart lock or an access-control panel suits the site better. That check matters more, not less, when the inside face is keyed.
What to check before choosing a
Most of the risk in this category is decided before anything is installed. The checks below are the ones that change the answer, and they are worth completing in order.
- Confirm the door is not a required escape route, or that another door serves that purpose.
- Check the door condition, including frame strength, alignment, and whether the existing bore suits a deadbolt.
- Decide how the inside face will be opened in an emergency, and who holds that method.
- Map user permissions. who enters, who exits, at what hours, and with which credential.
- Agree a backup entry method for power loss, reader failure, or a lost credential.
- Verify that the specific lock supports keyed-both-sides operation before purchase, using manufacturer documentation.
- Plan key and credential control, including what happens when a staff member leaves.
The sixth check is the one most often skipped. Double cylinder deadbolts are common hardware, and electronic deadbolts are common hardware, but a product that is genuinely both is a narrower set. Manufacturer documentation is the only reliable confirmation.
Door condition and site survey
A deadbolt needs a solid frame and a door that closes squarely. A frame that has softened, a door that has swollen, or a bore that sits too close to the edge can all prevent a clean fit, and the electronic layer does not fix any of that.
Eyonic's installation process begins with a site survey and a system proposal before installation and handover. For a keyed-both-sides deadbolt, the survey is where the escape-route question and the door condition question get answered together.
User permissions and backup entry
Permissions decide who can open the door and when. On a keyed-both-sides deadbolt, permissions also decide who can leave, which is a different list and often a longer one.
Backup entry needs a defined answer rather than an assumption. If the reader loses power or a credential stops working, the inside cylinder is still there, and the key for it needs to be somewhere reachable by the people who need it and not by anyone else.
How Eyonic approaches smart lock and access control work
Eyonic Sdn Bhd plans, supplies, and installs security and ELV systems in Sarawak, covering homes, offices, shops, and industrial sites. Smart lock door access is offered as a multi-brand line, and the review guidance is that smart locks work best when door condition, user roles, and backup method are reviewed before installation.
For business sites, the usual question is whether a standalone smart lock or an access-control panel is the better fit. A keyed-both-sides deadbolt pushes that question further, because the panel may be the only way to manage exit permissions properly.
Completed work includes the Kuching Immigration Office, where the focus was arrival flow, staff areas, visitor movement, and dependable daily operation, and KTA Sarawak Sdn Bhd, where the focus was staff movement, visitor handling, and tidy cabling. Both are examples of access decisions being made around how a building is actually used.
Eyonic's founder, Eric Yong, has worked in the industry for more than ten years, with experience in technical installation of digital security solutions for commercial businesses in Sarawak.
Package pricing for related systems sits at RM 1,599 for a Hikvision CCTV package, RM 1,599 for a Hikvision alarm system, and RM 1,599 for an autogate package. Project budgets for the two completed sites fell in the RM 12,000 to RM 28,000 and RM 8,000 to RM 18,000 ranges. No verified price for a double key deadbolt smart lock in Malaysia is available here, so none is quoted.
Share your location, property type and required system with Eyonic on WhatsApp at +60 11-5111 7959 for the next practical step.