11.1 Pre-Design, Schematic, Construction Docs, Calculations & Drawings

Physical security systems rarely fail first because an attacker invented a new trick. They fail because the bid set never said what “done” looks like, or because the installer had to guess where power, data, and coverage were supposed to land. For the PSP exam, design documentation is the working language of Domain 2 Task 3: it turns assessment decisions into a package another professional can price, permit, install, and test.

Treat the four classic phases as a progressive freeze. Each phase spends more design effort in exchange for fewer surprises at bid. If an item describes concept camera bubbles, a technology direction, and a rough-order-of-magnitude budget, you are in schematic design. If it describes door elevations, riser homeruns, cable schedules, and specification product data, you are in construction documents. Mixing those deliverables is a common distractor.

Pre-design and programming

Pre-design, often called programming on building projects, defines the problem before anyone selects a camera. The security designer converts the assessment narrative into a basis of design: which assets require protection, which outcomes were accepted (detect, delay, respond, recover), which owner standards and adopted codes apply, and which site constraints will dominate later drawings.

Programming inputs include the architectural program (occupancy, hours, public versus restricted zones), threat and vulnerability conclusions from assessment work, existing conditions (legacy panels, analog cameras, door hardware, leftover wall space in an intermediate distribution frame), information-technology rules for placing security devices on the enterprise network, and authority having jurisdiction (AHJ) expectations. Outputs are written, not verbal: zone-level device-type counts, operational concepts (who badges where, who monitors alarms, who unlocks after hours), a preliminary budget range, and a roster of other disciplines that must sit at the table—the architect, electrical engineer, door-hardware consultant, fire protection engineer, elevator contractor, parking operator, and HR/identity owner.

Programming is also where impossible combinations get documented: a fully transparent glass lobby, an owner who wants facial identification at 80 feet, and decorative lighting specified at 5 lux. Those conflicts belong in a program memo. If they wait for a punch list, millwork and storefront are already fabricated.

Schematic design

Schematic design (SD) tests whether a protection concept can live in the architecture. Device symbols appear on plans at a conceptual level: portals, camera views covering those portals, intrusion zones around the shell, head-end rooms, and major raceway corridors. Technology direction is stated in sentences such as “network video with server-based recording,” “Power over Ethernet (PoE) access control at the door,” or “balanced magnetic switches on exterior openings,” without locking every stock-keeping unit.

SD drawings are still allowed to move. Their job is to support owner decisions and a schematic cost model. If the owner eliminates a staffed vehicle gate at SD, restudy delay at the pedestrian lobby immediately. Carrying an SD bubble into a construction bid as if it were a counted device is how camera counts magically grow during construction.

Design development

Design development (DD) is where the system becomes buildable in principle. Door hardware sets are coordinated so a fail-secure mortise lock, door position switch, request-to-exit device, and reader actually fit the specified frame and fire rating. Camera mounting heights and aiming assumptions are checked against ceiling types, sun angles, and lighting. Panel locations, PoE switch counts, backup power, and network drops are coordinated with electrical and communications disciplines. Product families are usually selected so storage, licensing, and cable distances can be calculated rather than guessed.

DD is the last inexpensive moment to change architecture. Relocating a manned lobby after DD often means millwork, storefront, and electrical already in fabrication. Exam items that mention hardware sets coordinated and calculations started are pointing at DD, not at programming.

Construction documents

Construction documents (CDs) are the bid and permit set: complete device plans, door and camera schedules, elevations, details, risers, and specifications. A competent CD package lets two qualified bidders price the same scope. Ambiguity here does not create flexibility. It creates change orders and silent gaps—the camera that was “obvious” on an SD bubble but never received an identifier on the CD plan.

CDs are also the set the AHJ and the engineer of record will interrogate. If battery standby, magnetic-lock release on fire alarm, or barrier foundations require stamped engineering, those calculations and details must be in or referenced by this package. A vendor pamphlet is not a construction document.

Calculations: power, storage, and coverage

Three calculation families show up repeatedly: power, storage, and coverage. Completing them is part of competent security design. Stamping them as engineering documents, where state law requires a license, is a different legal act.

Power. Count energized loads: lock current (inrush versus holding), reader, auxiliary relays, illuminators, outdoor camera heaters, and panel overhead. Separate lock power from electronics when the specification requires it. For PoE, check both watts per port and the switch’s total PoE budget—sixteen 20-watt cameras on a 240-watt switch is a math failure, not a commissioning surprise. Standby time is an owner and AHJ requirement, not a catalog default. Fire-alarm standby is often specified through the adopted fire-alarm standard; electronic security standby may be an owner four-hour rule, a campus standard, or a listed power-supply specification. Document assumed hours, load, and battery temperature derating, then route the package to whoever is legally responsible for electrical calculations in that jurisdiction.

Storage. Video storage is retention policy expressed in terabytes. A defensible estimate uses camera count, recorded resolution and frame rate, codec and scene complexity (bitrate), hours recorded per day, retention days, and RAID or filesystem overhead (commonly about 20–30 percent plus hot spare). Motion-only recording is not free: a busy dock may record nearly continuously. If investigations need 90 days of 1080p at 15 frames per second on 200 cameras, write that number into the basis of design so later cost cutting cannot silently reduce retention to seven days.

Coverage. Coverage is spatial proof that detection and assessment are possible. For video, that is field of view plus pixel density at the target (detection versus recognition versus identification), mounting height, and lighting. For intrusion, it is zone layout, beam geometry, and nuisance-alarm sources. For access control, it is portal count, anti-passback zones, and whether each opening has the correct device set for the lock function. Coverage worksheets belong in the design file. “Typical 90-degree lens” on a sales slide is not coverage.

Drawings, data sheets, and design review

A security drawing set is a coordinated language, not a pile of marketing PDFs.

A typical door elevation is the exam’s favorite drawing. It stacks the reader height, lock function, door position switch, request-to-exit device, and any delayed-egress or magnetic-lock hardware on the same opening, with notes that send the lock to the openings specification and the electronics to the security specification. A camera schedule lists identifier, function (detect, recognize, identify), lens or field-of-view assumption, mounting height, illumination, and recording settings so storage calculations have a source. A riser shows how those devices home to controllers, PoE switches, lock power supplies, and the head-end—without pretending the floor plan can carry all of that topology.

Technical data sheets (cut sheets) support calculations during design (PoE class, illuminance, detection range) and become submittal evidence during construction. They do not replace a door elevation. Design review is a scheduled interrogation by security operations, IT, facilities, the architect, the electrical engineer, and—when life safety is involved—the fire protection engineer and AHJ. Close comments before bid. A review after award is a change-order engine.

Who stamps what: coordination, not a substitute license

Exam items mix three roles. Keep them distinct.

The licensed Professional Engineer (PE), where state law requires it, is the engineer of record for engineering documents: electrical distribution, fire alarm, structural foundations for barriers or poles, and life-safety interface logic that constitutes the practice of engineering. Holding a PSP credential does not confer a PE stamp, and this chapter is not telling you to stamp work you are not licensed to stamp.

The security designer (in-house practitioner, consultant, or design-assist vendor) authors the security program, device layouts, security specifications, and worksheets that state loads and performance. That person coordinates with the PE rather than impersonating one. When an AHJ demands stamped voltage-drop or battery calculations, the project routes those sheets through the electrical or fire-protection engineer using the security designer’s device schedule as input.

The installer produces shop drawings, product submittals, and as-builts. Shop drawings show how the contractor will meet the construction documents; they are not a license to redesign detection. As-builts record what was installed after requests for information and change orders. A contractor license and a PE license are different legal instruments.

Good coordination looks like this: the security designer publishes door and camera schedules with load and mounting data; the electrical engineer sizes circuits, panels, and generator or UPS contributions; the architect owns the door and frame; the hardware consultant owns the lock function; the fire protection engineer owns maglock release and door-hold-open behavior on alarm; the installer submits shop drawings that match those decisions. When those people do not talk, a perimeter door receives a fail-safe lock because “that is how the electrician always wires it.”

Read the diagram left to right as increasing freeze, not as four names for the same PDF. Calculations start in earnest at design development because product families and door counts are stable enough to size power and storage. Drawings become bid instruments only at construction documents. Shop drawings and as-builts come later, during implementation, and they answer to this issued set rather than replacing it. If an exam stem hands you a “complete” package that still lists cameras as unnamed bubbles and lock power as “by others, maybe,” you are not looking at construction documents—you are looking at an unfinished schematic that someone tried to bid.