This step is crucial and largely determines whether your home can install it and how smoothly the installation will proceed.
1. Confirm Door Type and Material:
Condition: For new doors, drill holes according to the lock.
Type and Material: Is it a security door, wooden door, iron door, thermally broken aluminum door, glass door, single-leaf or double-leaf door?
Opening Direction: Does the door open inwards or outwards? Left or right? This determines the orientation of the lock body, which must be accurately selected when purchasing.
Double Doors: In Guangdong, many families install double doors for security; consider whether the lock handle will touch the door.
2. Precisely Measure Existing Door Thickness and Guide Plate Dimensions When Replacing the Lock with a Fingerprint Scanner:
Guide Plate (Lock Body Protective Plate): The long strip of metal attached to the side of the door after removing the old lock. Measure its length, width, and thickness. This is the most critical dimension for selecting a new lock body.
Lock Body Dimensions: Primarily measure the distance from the center of the handle to the edge of the door.
Door Thickness: Measure the door thickness with a tape measure. Common security door thicknesses are 5-10cm, and wooden doors are 4-5.5cm thick.
Top and Bottom Hooks: Check if your door has top and bottom hooks. Recommendation: For security and stability, avoid using top and bottom hooks when installing a Fingerprint Scanner.
3. Take Photos: Before removing the old lock, take clear photos of the original lock from different angles (inside, outside, and side) with your phone, including the lock cylinder, lock body, and guide plates. These photos are the best evidence when purchasing a new lock and communicating with customer service.