Three components of Tactical
Diagramming
• Science
• Planning and building codes
• Terrain Analysis
• Art
• Personal intuition, imagination
and ingenuity
• A technique—not a tactic!
• Procedures for performing
specific tasks or functions
• Skill
• Building practices and
tactical diagramming practice
BuildingCodes
• National Building Code of Canada
• Adopted in 1941
• Originally instituted for fire
prevention and escape
• Model code rather than
regulatory but usually
adopted locally
as requirements
• Local zoning ordinances
Reverse Engineering
• Mentally disassembling a house to
visualize the interior
• Knowledge of building code requirements
helpful but not essential
• Familiarization with building practices is largely
already available
• Personal experiences and observations
• Especially useful for police and military
• All buildings are built for a purpose and many
are altered to suit particular uses
Building Practices
• Driven by economic
and aesthetic factors
• Size and shape of house
and organization of rooms
• Expense of installation
and cost of materials
• Cultural conventions
• Enables mass produced goods and
components
• Examples include window coverings,
hardware, cabinets, furniture, plumbing
fixtures, and so forth
• Some have been incorporated into local
ordinances
• Just as influential as regulations
• Tend to be universal rather than regional
Building Principles
• Four elements that must be controlled
• Fire, Wind, Water, Gravity
• Use of building will strongly influence
construction
• Buildings are hollow
• Limitations on span by materials and expense
• Nearly all residences in America are "stick
framing"
• Interior walls are used for intermediate support
• Bearing walls are more predictable than
partitions
Coup d'oiel
• French—"The vision behind the eye"
• English translation—perceptive insight
• An ability to "see" on the other side of the hill
or inside a house
• Part art
and
part science
Helpful Hints
• Work from large to small
• Start with orientation
• Next go to building outline
• Diagram floor plan last
• Work from confidence to ambiguity
• Sketch in as many features that can be reliably
placed and sized first
• Compare
• What you know or believe to what you see
• Be suspicious—explain incongruities
• Don't be afraid of "I don't know!"
Residential Trivia
• Size of house ~2,450 square feet (median)
• Typical three-bedroom in Southwest USA is about 1,400 sq. ft.
• 80% built since 1920
• About 2/3 will have an attached garage or
carport
• Almost half will have a separate dining room
• More than 2/3 are occupied by the owner
• More than 3/4 are single-family structures
• Approximately 90 million homes in USA
• Each has more in common with the others than differences
Frequently Asked Questions
• Why focus on residences?
• Most common target for warrants
• Public buildings provide far easier access to gain info
• How long does it take?
• Varies with amount of desired detail and complexity of
building
• Generally, figure 60-90 minutes for most applications
• How accurate can a diagram be?
• Depending on resource photos, as close as six inches
for a room and a foot for a building
• Features can be precise!
• Many features, like doors and windows, can be
estimated within one inch
Useful Tools
• ¼ʺ graph paper
• Good scale for nearly all diagrams
• Mechanical pencil with HB lead
• Soft lead with dark lines but easily erased
• Compass or dividers
•
Easy and accurate transfers of scale
• Gum eraser, especially pen style
• Computer software
• By far, the easiest and simplest method for
diagramming
• Some are automatically defaulted for sizes
and codes
• Provide instant 3D versions, including walkthroughs
• Sketchup—free version from Google
• Chief Architect—Better Homes and Gardens
• Punch Pro—Punch Software, less than $100
Useful Books
• Look for illustrations as
well as narrative
• Comprehensive
overview is better than
detailed information
• You don’t need to read
them, you’ll use them
for reference and
precision
Tactical Diagramming Book
• Used as text for this course
• Written from a tactical
perspective rather than
a builder’s
• Heavily illustrated with
examples, graphics,
photographs, etc.
• Focused entirely on tactical
diagramming