panic-room-finder

Use for:

• Mapping house dimensions room-by-room
• Identifying discrepancies suggesting hollow spaces
• Understanding historical hidden space patterns
• Non-destructive investigation techniques
• Safe room planning and conversion
• Exploring potential access points

NOT for:

• Illegal entry or trespassing
• Bypassing security systems
• Structural modifications without permits
• Anything that compromises home safety
• Breaking into spaces in rental properties without owner permission

```

┌─────────────────────────────────────────────────────────────────┐

│ HOLLOW SPACE DISCOVERY FLOW │

├─────────────────────────────────────────────────────────────────┤

│ │

│ 1. DOCUMENT 2. MEASURE 3. COMPARE │

│ ├─ Blueprints ├─ Room-by-room ├─ Floor plan vs. │

│ ├─ Building history ├─ Floor to floor │ actual dims │

│ ├─ Age/era ├─ Wall thickness ├─ Room totals vs. │

│ └─ Previous owners └─ Closet depths │ exterior │

│ │

│ 4. IDENTIFY 5. INVESTIGATE 6. ACCESS │

│ ├─ Anomalies ├─ Non-destructive ├─ Find entry │

│ ├─ Unusual walls ├─ Acoustic test ├─ Mechanical │

│ ├─ Odd closets ├─ Visual inspection │ triggers │

│ └─ Stair gaps └─ Camera scope └─ Safe opening │

│ │

└─────────────────────────────────────────────────────────────────┘

```

By Era

```

COLONIAL ERA (1600s-1800s):

├── Priest holes (religious hiding)

├── Slave passage rooms (Underground Railroad)

├── Root cellars with hidden sections

├── False chimney breasts

└── Hidden attic spaces

VICTORIAN ERA (1837-1901):

├── Servant passages between walls

├── Hidden butler's pantries

├── False walls in grand staircases

├── Hidden safes behind panels

└── Speaking tubes with hidden terminals

PROHIBITION ERA (1920-1933):

├── Speakeasy access tunnels

├── Hidden bars behind bookcases

├── False floor compartments

├── Basement hidden rooms

└── Garage false walls

MID-CENTURY (1940s-1960s):

├── Cold War fallout shelters

├── Basement bomb shelters

├── Hidden passages in large homes

├── False wall safes

└── Converted coal storage

MODERN ERA (1970s+):

├── Safe rooms (security)

├── Hidden gun safes

├── Converted closet spaces

├── Basement vault rooms

└── Custom hidden doors

```

By House Type

```

OLDER HOMES (pre-1950):

├── More likely to have organic hidden spaces

├── Multiple renovation layers

├── Unusual floor plans from additions

├── Thick walls with potential voids

├── Servants' quarters/passages

LARGE ESTATES:

├── Purpose-built hidden rooms

├── Panic rooms in master suites

├── Wine cellars with hidden sections

├── Basement vault rooms

└── Tunnel systems to outbuildings

URBAN ROWHOUSES:

├── Shared wall anomalies

├── Basement connections

├── Attic spaces across units

├── Coal chute conversions

└── Back stair hiding spaces

SUBURBAN HOMES:

├── Basement safe rooms

├── Under-stair storage (deeper than expected)

├── Garage hidden compartments

├── Attic access panels to hidden space

└── Crawl space extensions

```

Step 1: Gather Documentation

```

DOCUMENTS TO FIND:

├── Original blueprints (check county records)

├── Building permits (all renovations)

├── Survey maps (property lines, structures)

├── Previous listing photos (real estate archives)

├── Insurance inspection records

└── Historical society records (for older homes)

WHERE TO LOOK:

├── County recorder's office

├── Local building department

├── Historical society

├── Previous owner records

├── Original builder/architect (if known)

└── Realtor's historical files

```

Step 2: Room-by-Room Measurement

```

MEASURING PROTOCOL:

TOOLS NEEDED:

├── Laser distance measurer (highly recommended)

├── Standard tape measure (backup)

├── Graph paper (1/4" grid)

├── Smartphone (photos, notes)

└── Level (for checking true walls)

MEASUREMENT APPROACH:

├── Start from exterior walls (measure outside perimeter)

├── Measure each room interior

├── Measure wall thicknesses at doorways

├── Note ceiling heights per room

├── Measure closet depths especially

└── Record unusual features (alcoves, bumps, niches)

FORMULA:

Exterior perimeter area MINUS sum of interior room areas

= Total wall/void space

If this number is significantly larger than expected

for wall thickness (typically 4-8" per wall),

you may have hidden space.

```

Step 3: Floor-to-Floor Analysis

```

VERTICAL DISCREPANCIES:

Check for:

├── Floor height differences between rooms

├── Ceiling height vs. floor above

├── Stair landing positions vs. expected floor levels

├── Basement ceiling vs. first floor

└── Attic floor vs. rooms below

RED FLAGS:

├── "Lost" height between floors (2+ feet unexplained)

├── Stairs that should arrive somewhere but don't

├── Rooms that are shorter than adjacent rooms

├── Attic space that doesn't extend over whole house

└── Basement that doesn't extend under entire first floor

```

Visual Indicators

```

WALL CLUES:

├── Wall that sounds different when knocked (hollow vs. solid)

├── Trim or molding that doesn't match rest of house

├── Paint that doesn't quite match (newer patch)

├── Outlet plates at unusual heights

├── Baseboards that don't align with rest of room

├── Wallpaper seams in unexpected places

└── Door that opens to unexpected small space

FLOOR CLUES:

├── Flooring that doesn't match pattern

├── Areas that sound hollow when walked on

├── Unusual wear patterns to non-functional spot

├── Carpeting that's newer in one section

├── Floor register that doesn't connect to HVAC

└── Trapdoor-like cuts in hardwood

CEILING CLUES:

├── Attic access panels in unusual locations

├── Ceiling height changes within room

├── Crown molding that stops unexpectedly

├── Light fixtures in odd positions

├── Texture changes in ceiling

└── Evidence of patched openings

```

Mechanical Indicators

```

THINGS THAT MIGHT BE TRIGGERS:

├── Bookcases that seem heavier than expected

├── Wall sconces that don't work

├── Decorative panels that seem functional

├── Built-in cabinets with unusual depth

├── Fireplaces with odd proportions

├── Mirror frames that seem attached unusually

├── Light switches that don't control anything

└── Door frames with hidden hinges

COMMON HIDDEN DOOR MECHANISMS:

├── Push-release latches (push to open)

├── Hidden lever in adjacent object

├── Magnetic releases (strong magnet needed)

├── Remote control systems

├── Biometric locks (newer)

├── Book-pull releases (classic)

└── Light switch combinations

```

Acoustic Testing

```

THE KNOCK TEST:

1. Use knuckle or small rubber mallet
2. Knock systematically across wall surface
3. Listen for changes in sound:

├── Solid: dull thud

├── Stud: slightly different thud (every 16")

├── Hollow: distinct hollow sound

└── Void: VERY hollow, almost drum-like

1. Mark suspicious areas with painter's tape
2. Map the hollow-sounding zones
3. Compare to expected wall construction

```

Electronic Detection

```

STUD FINDER (with limitations):

├── Can detect studs and sometimes wires

├── May show unusual spacing or gaps

├── Deep-scanning models better for this

└── Won't reveal what's in a void

THERMAL CAMERA:

├── May show temperature differences

├── Hidden rooms might be unconditioned (different temp)

├── Can reveal hidden ductwork or lack thereof

└── Smartphone attachments available (FLIR, etc.)

BORESCOPE/ENDOSCOPE:

├── Tiny camera on flexible cable

├── Insert through small drilled hole

├── See inside wall cavity

├── $20-100 USB versions work for most uses

├── Only use if you're VERY confident there's something

└── CAREFUL: This is minimally destructive

MOISTURE METER:

├── Can detect unusual moisture patterns

├── Hidden rooms without HVAC may be damper

├── Also useful for finding water damage

```

Visual Inspection Points

```

CHECK THESE ACCESS POINTS:

├── Attic: look for unused space, false floors

├── Basement: look for unusual walls, false ceilings

├── Utility closets: often hide access

├── Under stairs: classic hiding spot

├── Walk-in closets: check depth vs. adjacent room

├── Behind large mirrors: especially built-ins

└── Inside large cabinets: check for false backs

```

When You Find a Hidden Space

```

BEFORE OPENING:

1. ASSESS SAFETY

├── Is the structure sound?

├── Any signs of current use? (fresh locks, etc.)

├── Any electrical/utility concerns?

└── Any reason to involve professionals?

1. DOCUMENT

├── Photo everything before touching

├── Note the mechanism details

├── Record location precisely

└── Video the opening process

1. VENTILATION CHECK

├── Sealed spaces may have poor air

├── Have someone with you

├── Open slowly, let air exchange

└── Don't enter immediately if sealed for long time

1. PROCEED CAREFULLY

├── Use flashlight first (don't enter)

├── Check for stability of floor/structure

├── Look for animal/pest evidence

└── No rushing—this space isn't going anywhere

```

What You Might Find

```

COMMON DISCOVERIES:

├── Empty space (most common)

├── Old storage (forgotten items)

├── Previous owner's hidden stash

├── Historical artifacts

├── Old newspapers/letters (insulation era)

├── Evidence of previous use (Prohibition, WWII)

├── Animal nests (abandoned space)

└── Outdated utility equipment

RARE BUT POSSIBLE:

├── Valuable items left behind

├── Historical significance

├── Structural concerns (why it was sealed)

└── Evidence of concerning activity (call authorities)

IF YOU FIND ANYTHING CONCERNING:

├── Do not disturb

├── Document with photos

├── Contact appropriate authorities

└── Wait for professional guidance

```

If You Want to Create a Panic Room

```

IDEAL SAFE ROOM FEATURES:

├── Solid core door (or reinforced)

├── Door frame reinforcement

├── Secondary lock system (interior)

├── Communication (cell phone, landline, intercom)

├── Emergency supplies (water, first aid)

├── Battery backup for lights

├── Ventilation (passive or emergency)

└── Comfortable waiting capacity

LOCATION PRIORITIES:

├── Near bedrooms (accessible during home invasion)

├── Cell phone signal availability

├── Away from exterior walls (if possible)

├── Not obvious location (closet within bedroom)

└── Accessible to all family members

DIY VS. PROFESSIONAL:

├── Basic: reinforced closet (DIY possible)

├── Moderate: dedicated room conversion (contractor)

├── Advanced: purpose-built room (security specialist)

└── Always consult local building codes

```

Room-by-Room Recording Sheet

```

ROOM: _______________

FLOOR: _______________

DIMENSIONS:

├── Length: _____ ft _____ in

├── Width: _____ ft _____ in

├── Height: _____ ft _____ in

└── Area: _____ sq ft

WALL THICKNESSES:

├── North wall: _____ in

├── South wall: _____ in

├── East wall: _____ in

└── West wall: _____ in

ANOMALIES NOTED:

├── Sound test results: _____________

├── Visual irregularities: _____________

├── Dimension discrepancies: _____________

└── Notes: _____________

ADJACENT SPACES:

├── Room to north: _______________

├── Room to south: _______________

├── Room to east: _______________

├── Room to west: _______________

├── Above: _______________

└── Below: _______________

```

"Knocking Is Enough"

Wrong: Only doing the knock test and concluding.

Why: Many factors affect wall sound; need multiple methods.

Right: Combine knock test + measurements + visual inspection.

"Breaking Through"

Wrong: Making holes to investigate.

Why: Destructive, may damage hidden room, hard to repair.

Right: Use borescope only after exhausting other methods.

"Ignoring Safety"

Wrong: Entering a sealed space immediately.

Why: Air quality, structural stability, unknown hazards.

Right: Ventilate, document, assess before entering.

"Not Documenting"

Wrong: Just exploring without recording.

Why: You may forget details, lose evidence of discovery.

Right: Photos, videos, measurements before and during.

• diagramming-expert: Creating floor plans of findings
• interior-design-expert: Converting found space
• drone-cv-expert: Exterior mapping for discrepancy detection

---

Core Philosophy: Hidden spaces tell stories. Whether your house was a stop on the Underground Railroad, a Prohibition speakeasy, or just had an eccentric previous owner, the architecture remembers. Your job is to be a detective—patient, methodical, and respectful of what you might find.

Every hollow knock is a question. Take your time finding the answers.