Rekeying vs Replacing Locks Cost & Decision Guide

# Rekeying vs Replacing Locks: Complete Cost Guide for St. Louis Homeowners

When keys are lost, homes are purchased, or security is compromised, St. Louis homeowners face a choice: rekey existing locks or replace them entirely. Understanding the differences, costs, and appropriate scenarios for each option saves money while ensuring proper security.

As locksmiths serving St. Louis since 2010, we help homeowners make informed decisions about lock security. This comprehensive guide explains when rekeying makes sense, when replacement is necessary, and how to evaluate your specific situation.

Understanding Lock Rekeying

Rekeying changes the internal pins and springs inside a lock cylinder so old keys no longer work. A locksmith removes the cylinder, replaces the pin configuration, and cuts new keys matching the new configuration.

What Stays the Same: The lock hardware, finish, and door installation remain unchanged. From the outside, nothing looks different.

What Changes: The key pattern required to operate the lock. Old keys become useless; only new keys work.

Process: A qualified locksmith completes rekeying in 10-15 minutes per lock on-site at your St. Louis home.

Understanding Lock Replacement

What Changes: All visible and mechanical components. The lock may look different, operate differently, and provide different security levels.

What May Change: Door preparation may be modified if new locks use different dimensions than previous hardware.

Process: Replacement typically takes 30-45 minutes per lock, depending on door condition and hardware compatibility.

Cost Comparison for St. Louis Homes

Rekeying Costs

First Lock: $75-150 including service call Additional Locks: $15-30 each when done simultaneously Typical 3-Lock Home: $150-225 total

Example: Rekeying front door, back door, and garage entry in a Kirkwood home costs approximately $175 when done together.

Replacement Costs

Labor Per Lock: $75-125 (installation time) Hardware Per Lock: $40-300+ depending on quality Total Per Lock: $115-425+ Typical 3-Lock Home: $345-1275+

Example: Replacing three standard deadbolts in a Webster Groves home with mid-grade Schlage locks costs approximately $450-600 including labor and hardware.

Cost Savings Summary

Rekeying costs 50-70% less than replacement when existing locks function properly. A homeowner rekeying 4 locks saves $400-800 compared to replacement with comparable hardware.

When Rekeying Makes Perfect Sense

New Home Purchase

Situation: You just bought a home in Chesterfield, Clayton, or any St. Louis neighborhood. Previous owners, real estate agents, contractors, and showing visitors may have had key access.

Solution: Rekey all exterior locks immediately after closing. This costs $200-300 for typical homes and guarantees only you control access.

Why Not Replace: If existing locks are quality brands (Schlage, Kwikset, Baldwin) in good condition, replacement wastes money without improving security.

Lost or Stolen Keys

Situation: Keys lost at Forest Park, stolen from car, or misplaced with identifying information.

Solution: Rekey affected locks immediately. For $75-150, you eliminate security concerns without expensive replacement.

Why Not Replace: Unless locks are already problematic, new hardware provides no security advantage over rekeying.

Ending Relationships

Situation: Divorce, roommate moves out, or relationship ends where other party had keys.

Solution: Rekey all locks they could access. This costs less, happens faster, and provides equivalent security to replacement.

Timing: Many St. Louis locksmiths offer same-day rekeying for these situations.

After Contractor Access

Situation: Renovations in your Ballwin or Maplewood home required giving contractors keys. Work is complete.

Solution: Rekey all locks contractors accessed. This protects against unreturned keys or unauthorized copies.

Why Not Replace: Construction dust and use may warrant replacement if locks were damaged, but otherwise rekeying suffices.

Simplifying Key Management

Solution: Rekey all locks to operate with one key. This costs $200-350 for most homes and eliminates key confusion.

Benefit: "One key opens everything" convenience without replacing functional hardware.

When Adding New Locks

Situation: You install a new deadbolt on your basement door. Now you have another key to carry.

Solution: Have a locksmith rekey the new lock to match your existing keys. This costs $15-30 when done during installation.

When Lock Replacement is Necessary

Damaged or Worn Locks

St. Louis Factors: Our freeze-thaw cycles and humidity accelerate lock wear. Locks on older St. Louis homes may need replacement after 15-20 years even with proper maintenance.

Solution: Replace damaged locks with quality hardware. Attempting to rekey failing mechanisms wastes money when lock fails shortly after.

Security Upgrade Needs

Solution: Replace with Grade 1 or Grade 2 ANSI-rated deadbolts. Homes in Clayton, Ladue, and other areas with valuable contents benefit from high-security Medeco or Mul-T-Lock systems.

Cost vs Value: Spending $200-400 on quality locks for front and back doors protects $200,000+ homes. The math favors proper security hardware.

Incompatible Lock Types

Challenge: Different brands use different keyway designs. Rekeying to single key requires all locks use compatible cylinders.

Options: 1. Replace some locks to standardize on one brand, then rekey all 2. Rekey each brand separately (requires multiple keys) 3. Replace all locks with one brand for single-key convenience

St. Louis Recommendation: Many older St. Louis homes have accumulated mismatched locks over decades. Complete replacement to standardize is often the most practical long-term solution.

Changing Lock Functions

Reality: These changes require replacement. Rekeying only changes key patterns, not lock functions or hardware type.

Style and Finish Updates

Situation: Renovating your Kirkwood home and changing from brass to brushed nickel hardware to match new fixtures.

Reality: Rekeying doesn't change visible appearance. Matching updated home aesthetics requires replacement.

Opportunity: When replacing for aesthetic reasons, upgrade to higher security simultaneously for maximum value.

Detailed Cost-Benefit Analysis

Rekeying Advantages

Cost Savings: 50-70% less expensive than replacement for equivalent security Speed: 10-15 minutes per lock vs 30-45 minutes for replacement No Door Damage: Existing hardware stays, no new holes or modifications Environmental: Reuses functional components rather than creating waste Immediate Security: Same-day service available from most St. Louis locksmiths

Best For: Functioning locks needing new key patterns

Replacement Advantages

Security Upgrade: Opportunity to install significantly better locks Fresh Start: New mechanisms without wear or hidden damage Aesthetic Update: Match new hardware to updated home style Warranty: New locks include manufacturer warranties Standardization: Choose one brand ensuring future rekey compatibility

Best For: Worn locks, security upgrades, or aesthetic renovations

Break-Even Analysis

Special Considerations for St. Louis Homes

Historic St. Louis Homes

Neighborhoods: Lafayette Square, Shaw, Compton Heights, Old Town Florissant

Considerations: Historic homes often have unique or antique locks. Replacement may require custom solutions or compromise historic authenticity.

Recommendation: Attempt rekeying first to preserve original hardware. Many antique locks can be rekeyed by experienced locksmiths. Replace only when rekeying isn't viable.

Rental Properties

Landlord Perspective: Rekeying between tenants costs $150-250 per property and ensures security. This is routine maintenance expense.

Replacement Timing: Replace locks every 5-7 years or when damaged. Budget $500-800 per property for complete lock replacement in typical 2-3 bedroom St. Louis rental units.

Legal Requirements: Missouri law doesn't explicitly require rekeying between tenants, but it's considered best practice and expected by renters.

Multi-Unit Properties

Situation: Apartment buildings or multi-family properties in University City, Clayton, or throughout St. Louis metro.

Solution: Master key systems allow rekeying individual units while maintaining master key access for property management. This requires professional planning but provides long-term flexibility.

DIY vs Professional Service

Rekeying

DIY Difficulty: Moderate to difficult Required Skills: Fine motor skills, patience, technical understanding Risk: Incorrect pin configuration leaves locks operable but insecure, or completely inoperable Cost Savings: $50-100 by doing yourself Reality: Most homeowners should hire professionals for rekeying

DIY Rekeying Kits: Available at Home Depot or Lowe's for $15-40, but require compatible lock brand and careful execution

Replacement

DIY Difficulty: Easy to moderate for standard installations Required Skills: Basic tools, measuring, patience Risk: Improper installation compromises security; wrong measurements damage doors Cost Savings: $75-125 per lock in labor Reality: Handy homeowners can replace standard locks successfully with proper research

St. Louis Recommendation: Professional installation ensures proper alignment critical for St. Louis weather extremes. Door swelling from humidity affects lock operation.

How to Decide: Decision Framework

Quick Decision Guide

Choose Rekeying If: ✓ Locks work perfectly ✓ Recent home purchase or lost keys ✓ Quality brand locks (Schlage, Kwikset, Baldwin) ✓ Budget under $250 ✓ Need service today

Choose Replacement If: ✓ Locks stick, jam, or malfunction ✓ Current locks are basic builder-grade ✓ Coordinating with renovation ✓ Want significant security upgrade ✓ Locks are 15+ years old

Questions to Ask

Common Myths Debunked

"Rekeying is just temporary security"

Myth: Rekeying provides inferior security to replacement.

Reality: Properly rekeyed locks provide identical security to new locks of the same model. Security depends on lock quality, not whether it's rekeyed or new.

"You can't rekey electronic/smart locks"

Myth: Smart locks can't be rekeyed.

Reality: Many smart locks (Schlage Encode, Kwikset, August retrofit) can be rekeyed just like traditional locks. The electronic components are separate from mechanical cylinder rekeying.

"Locks should be replaced every few years"

Myth: Locks need replacement every 3-5 years.

Reality: Quality locks last 15-20+ years with proper maintenance. Routine replacement wastes money unless upgrading security or addressing damage.

"Rekeying damages locks"

Myth: The rekeying process harms lock mechanisms.

Reality: Professional rekeying doesn't damage locks. It's a standard service that doesn't stress components beyond normal use.

Finding Quality Locksmith Service in St. Louis

Red Flags to Avoid

Pressure for Unnecessary Replacement: Some disreputable locksmiths claim rekeying "isn't possible" when it would work fine. Get second opinions for expensive recommendations.

Unmarked Vehicles: Professional locksmiths have company vehicles, uniforms, and identification.

Cash-Only: Legitimate businesses accept multiple payment methods.

Vague Pricing: Honest locksmiths provide clear estimates distinguishing service calls, labor, and parts.

What to Expect from Honest Service

Free Phone Estimates: Detailed cost estimates based on your description of needs.

Clear Explanations: Why they recommend rekeying or replacement for your specific situation.

Options Presented: Both solutions explained with pros, cons, and costs.

Written Quotes: Before starting work, written documentation of services and pricing.

Warranty Information: Clear explanation of service and parts warranties.

Maximizing Your Investment

If Choosing Rekeying

Do All Locks Simultaneously: Per-lock cost drops significantly when rekeying multiple locks in one visit.

Consider Master Key Systems: Only slight additional cost during rekeying, provides convenient access hierarchy.

Request Extra Keys: Having 4-6 keys cut during service costs less than future duplication trips.

Document New Key Codes: Keep key code information secure for future copies without returning original keys.

If Choosing Replacement

Standardize on Quality Brand: Schlage or Kwikset ensures future rekeying compatibility and part availability.

Upgrade Main Doors: If budget is limited, prioritize front and garage entry doors for quality hardware.

Consider Smart Locks Selectively: Front door smart lock plus traditional locks elsewhere balances convenience and cost.

Save Old Hardware: Keep removed locks as spares for interior doors or sheds.

Long-Term Planning

Maintenance Extends Lock Life

Annual Lubrication: Spray lubricant in keyway and on moving parts yearly.

Key Inspection: Replace bent or worn keys before they damage locks.

Tighten Screws: Check and tighten mounting screws annually.

Weather Protection: Apply silicone sealant around exterior locks exposed to weather.

St. Louis Specific: Our humidity and temperature swings stress locks. Maintenance prevents premature replacement.

Planning for Future Needs

Photo Inventory: Document all lock types, brands, and key codes for reference.

Key Codes Secured: Store key codes separately from keys for emergency locksmith service.

Locksmith Relationship: Establish relationship with reliable locksmith before emergency needs.

Budget Planning: Plan for rekeying every 3-5 years or replacement every 15-20 years.

Neighborhood-Specific Considerations

Clayton and Ladue

Higher property values justify premium replacement locks. Medeco or Mul-T-Lock high-security systems resist picking and bumping techniques. Cost: $300-600 per lock, but proportional to home value.

University City and Maplewood

Older housing stock may have outdated locks. Replacement opportunities during home updates. Balance security needs with property value.

Chesterfield and West County

Newer construction typically has adequate locks. Rekeying at purchase usually sufficient. Focus replacement budget on security system integration.

Historic Neighborhoods

Preserve historic hardware when possible. Specialized locksmiths can rekey antique locks. Replace only when functionality compromised beyond repair.

Making Your Decision

The rekeying vs replacement choice depends entirely on your specific situation:

For most St. Louis homeowners buying homes, losing keys, or needing simple security updates, rekeying provides perfect security at fraction of replacement cost.

For homes with worn locks, security upgrade needs, or coordinating with renovations, replacement offers better long-term value despite higher upfront cost.

For expert evaluation of your specific situation, honest recommendations, and professional service throughout St. Louis County, St. Charles County, and surrounding areas, call (314) 728-5700. We'll explain your options clearly and provide upfront pricing for both rekeying and replacement solutions.