Architectural drawings and schedules

The architectural drawings are the heart of most building sets. They define the building's layout, its walls, doors and windows, its envelope, its stairs and vertical circulation, its finishes and its life safety features, and they coordinate the work of every other discipline. They are also the largest part of most sets, with floor plans, enlarged plans, reflected ceiling plans, roof plans, elevations, sections, details and many schedules. This lesson walks through the architectural sheets in the order you will meet them, explains what each contains and how to read it, and spends time on the schedules and legends, the tables where much of the real information lives: door, window, room finish and partition type schedules.

The architectural general sheets

Architectural sheets usually open with general information: the architectural abbreviations, symbols and material legends, general notes, and often a code analysis or life safety summary. The code summary lists the governing building code and edition, the building's occupancy classification, construction type, building area and height, occupant loads, required fire separations and fire-resistance ratings, sprinkler status and exit requirements (CON-130 and CON-140 cover the codes themselves). For the reader, the code summary explains why walls have particular ratings and why doors have particular hardware and labels.

Many sets also include life safety or code plans: simplified floor plans showing fire separations and fire walls with their ratings, exit routes, travel distances, occupant loads for each space and the locations of fire extinguishers and fire alarm devices. These plans are an efficient way to understand the building's fire strategy and to see which walls, doors and penetrations need special care.

Floor plans

Architectural floor plans show, for each story:

• Exterior walls, interior partitions, columns and shafts, with wall type tags.
• Doors with their swings and door tags; windows with window tags.
• Room names and numbers, sometimes with areas.
• Stairs with their direction of travel (usually an arrow labeled UP or DN from the floor shown), number of risers and landings; elevators and escalators.
• Built-in items such as counters, cabinets, washroom fixtures and partitions.
• Grid lines and dimensions locating walls, openings and features.
• References to elevations, sections, details and enlarged plans.
• Keynotes and notes on specific items.

Overall plans of large buildings are often drawn at 1:200 or 1:100 (1/16" or 1/8" = 1'-0") and split into parts on separate sheets, with a key plan and match lines. Dimensioned plans at 1:100 or 1:50 (1/8" or 1/4" = 1'-0") give the layout information, and enlarged plans at 1:50 or 1:25 cover complex areas.

Partition types and wall assemblies

Rather than draw every wall in full, architects define wall types in a legend: a set of small sections, each showing a wall assembly with its tag, construction and properties. A typical partition type legend shows for each type:

• The layers: stud size and spacing, number and type of gypsum board layers on each side, insulation, and finishes.
• The height: to the underside of the ceiling, to the ceiling plus a short distance, or to the underside of the structure above ("to deck").
• The fire-resistance rating, if any, with a reference to the tested or listed assembly that achieves it.
• The acoustic rating, usually a sound transmission class (STC) value.
• Special notes, such as "seal top and bottom with acoustic sealant" or "provide deflection track at head".

Rated walls are among the most important items to read correctly. A fire-rated partition must use the exact tested assembly, run to the structure above, have its joints and head sealed with listed systems, and have every penetration by pipes, ducts and cables firestopped. Doors in rated walls need rated frames and doors with labels, and ducts need fire dampers. Construction managers often highlight rated walls on the plans in color to make sure every trade knows where they are.

In the United States, fire-resistance ratings for walls and floors are established by testing to ASTM E119 or UL 263, with firestop systems tested to ASTM E814 or UL 1479. Drawings commonly reference a UL design number (such as U419) or a Gypsum Association (GA-600) file number for each rated wall type.

Doors and the door schedule

Doors are tagged on plans and described in a door schedule, a table that typically lists for each door:

• Door number, usually linked to the room number.
• Size: width, height and thickness.
• Door type (referring to door type elevations showing flush, glazed, louvred or other designs) and material, such as hollow metal, wood or aluminum.
• Frame type (referring to frame elevations) and material.
• Fire rating, such as 20, 45, 60 or 90 minutes, with a required label.
• Hardware set number, referring to hardware groups in the specifications that list hinges, locks, closers, exit devices, stops and seals.
• Glazing type, finish, head, jamb and sill details, and remarks such as "card reader", "automatic operator" or "acoustic seals".

Door schedules drive large purchase orders, long lead times and many coordination items. Hardware in particular involves the architect, the hardware consultant, the door supplier, the electrical contractor (for electrified hardware and access control) and the owner's security team.

Windows, curtain wall and storefront

Windows are tagged by type rather than individually, and each type is shown in a window type schedule or legend with an elevation of the unit showing its overall size, operable and fixed panels, mullion layout and glazing types. Notes and the specifications give frame materials, glazing performance (U-value or thermal transmittance, solar heat gain, visible transmittance), safety glazing locations and testing requirements. Curtain wall and storefront systems are usually shown in large-scale elevations with typical mullion details, and the detailed engineering is done by the supplier in shop drawings.

A key distinction is between the nominal window size, the actual unit size and the rough opening into which the unit is installed. Schedules should state which they give, and the rough opening must allow for shims, insulation, sealant and flashing. Window sizes and sill heights must also be checked against the exterior elevations, the floor plans and the structural openings.

Room finish schedules

Finishes are usually given in a room finish schedule, listing for each room the floor finish and base, wall finishes (sometimes by wall: north, east, south, west), ceiling type and height, and remarks. Finish codes, such as CPT-1 for a carpet type or PT-2 for a paint color, refer to a finish legend and the specifications. Some projects use finish plans instead of or in addition to schedules, shading or hatching floor areas by finish type and tagging walls.

Reflected ceiling plans

Reflected ceiling plans (Lesson 4) show ceiling types, often by hatch or grid pattern, with ceiling heights noted in each room. Acoustic tile grids are drawn to show their layout and starting point, usually centered in the room so that border tiles are equal. RCPs also locate light fixtures, diffusers and grilles, sprinkler heads, speakers, smoke detectors, access panels and bulkheads, coordinated with the electrical and mechanical drawings. Because so many trades put something in the ceiling, the RCP is a key coordination drawing, and differences between it and the engineering drawings should be resolved before installation.

Exterior elevations and the building envelope

Exterior elevations show the building's faces with their materials, usually indicated by hatch and keynote: brick, metal panel, curtain wall, precast concrete, stucco or siding. They show window and door openings with their tags, control and expansion joints, louvers, canopies, signage and rooftop screens, and level markers for each floor and roof. Wall sections and envelope details then show the layers: cladding, air space or drainage cavity, insulation, the air barrier and vapor control layer, sheathing, studs or backup wall and interior finishes. Envelope details at windows, parapets, slab edges, penetrations and transitions between systems are where most leaks and failures start, so they deserve careful reading (CON-111 covers envelope construction).

Interior elevations and mounting heights

Interior elevations show walls with millwork, fixtures and accessories, and they give mounting heights: the heights of counters, sinks, mirrors, grab bars, switches, receptacles, dispensers, signs and other items. In washrooms, accessible counters and fixtures must meet specific dimensions, and the interior elevations, enlarged plans and accessibility details must be followed precisely.

In the United States, accessibility requirements come from the 2010 ADA Standards for Accessible Design, which apply to public accommodations and government facilities, and from building codes that reference ICC A117.1, Accessible and Usable Buildings and Facilities. Federal facilities may follow the Architectural Barriers Act standards.

Stairs, ramps and vertical circulation

Stairs appear on plans with an arrow showing the direction of travel and a note such as "18 R UP" (18 risers up). Enlarged stair plans and sections give the riser height, tread depth, landing sizes, handrail and guard heights, and nosing details. Codes limit maximum riser height and minimum tread depth, so the number of risers between two floors is calculated from the floor-to-floor height: for example, a floor-to-floor height of 3 600 mm divided into 20 risers gives 180 mm risers. Elevator shafts are shown with their pit depths, overrun heights and door locations, which must match the elevator supplier's requirements.

Roof plans

Roof plans show the roof from above: slopes and the direction of drainage (with arrows and percentages), high and low points, drains and scuppers, crickets that divert water around curbs, roof hatches and access, parapets and expansion joints, rooftop mechanical equipment on curbs or dunnage, and the locations of penetrations. Low-slope roofs are rarely truly flat; they slope to drains through sloped structure or tapered insulation, and the roof plan shows the layout. Comparing the roof plan with the structural framing plan and the mechanical roof plan is essential, because equipment loads, openings and curbs all affect the structure.