6.2 Space Planning: Creating Initial Drawings
Key Takeaways
- The schematic design drawing set includes floor plans, elevations, reflected ceiling plans (RCPs), finish plans, and sections — each communicating a distinct layer of design intent.
- Reflected ceiling plans show lighting, HVAC diffusers, sprinkler heads, and ceiling types as seen reflected onto the floor plan, and are the primary vehicle for preliminary lighting layouts.
- Graphic standards — consistent line weights, symbols, notation, and dimensioning — ensure drawings are legible and unambiguous for contractors and clients.
- The drawing set must be sufficient to communicate full design intent: every material, dimension, and relationship the contractor needs to price and build the project should be findable across the set.
The Drawing Set in Schematic Design
After the floor plan is approved, the designer produces a coordinated set of initial drawings that communicate the full design intent. Each drawing type addresses a different question — What are the walls? (plan), What are the vertical surfaces? (elevation), What is overhead? (RCP), What are the finishes? (finish plan), What is the section through the space? (section). Together they form a complete picture of the proposed interior.
Floor Plans
The floor plan is the primary drawing, drawn in plan view (looking straight down). It shows walls, doors, windows, built-in casework, major furniture, dimensions, and room labels. In schematic design, floor plans use poche (filled walls) to distinguish new from existing construction. The plan is drawn at a scale appropriate to the project — 1/8 inch = 1 foot for large commercial projects, 1/4 inch = 1 foot for most interiors, 1/2 inch = 1 foot for detail.
Elevations
Elevations are orthographic projections of vertical interior surfaces, drawn as if you are standing directly in front of the wall. They show wall finishes, millwork heights, door and window dimensions, signage locations, and installed fixtures. Interior elevations are critical for millwork-heavy spaces — kitchens, reception desks, restroom partitions — where vertical dimensions matter. Elevations are typically drawn at 1/2 inch or 3/4 inch = 1 foot.
What Each Elevation Must Show
- Wall and ceiling finishes with material callouts
- Millwork dimensions: countertop height (typically 36 inches for kitchens, 29 inches for ADA-accessible), upper cabinet depth and height
- Door and window heights, head heights, sill heights
- Fixture mounting heights (e.g., grab bars per ICC A117.1 §609)
- Base, chair rail, crown molding profiles if applicable
Reflected Ceiling Plans (RCPs)
The reflected ceiling plan is the most distinctive interior drawing. It shows the ceiling as if a mirror were placed on the floor — you look down at the floor plan and see the ceiling reflected back. This convention ensures the RCP aligns exactly with the floor plan for coordination. The RCP shows:
- Ceiling type and height (e.g., 9-foot ACT, 10-foot GWB)
- Lighting fixtures — type, location, switching
- HVAC diffusers and returns
- Sprinkler heads and fire-alarm devices
- Speakers and other ceiling-mounted equipment
- Ceiling grid pattern for suspended ceilings
Preliminary Lighting Layouts
The RCP is the vehicle for the preliminary lighting layout. The designer coordinates lighting with the floor plan — task lighting over workstations, ambient lighting in circulation, accent lighting on features. Key principles:
- Switching and zoning: group fixtures on circuits that match use patterns (daylit zones separate from interior zones)
- Daylight harvesting: place fixtures in rows parallel to windows so perimeter rows can be dimmed or switched separately
- Fixture spacing: follow manufacturer spacing criteria (SC) to avoid dark spots; typically spacing-to-mounting-height ratio of 1.0–1.5
- Emergency lighting: battery-pack fixtures or emergency-powered circuits per IBC Chapter 10
Finish Plans
The finish plan (also called a finish schedule or finish key plan) documents every wall, floor, and ceiling finish in the project. It typically uses a code system (e.g., FP-1, WP-3, CT-2) keyed to a finish schedule that lists material, manufacturer, color, and application. The finish plan is developed concurrently with the material selection process (covered in Section 6.3).
Sections
Sections are vertical cuts through the space, showing floor-to-ceiling relationships, volume, soffits, and clearances that cannot be read in plan or elevation. A section through a reception desk shows the desk height, the transaction counter at 36 inches (accessible), the overhead soffit, and the clear space above. Sections are essential for spaces with complex vertical geometry — stairways, mezzanines, dropped soffits, clerestory windows.
Graphic Standards
Consistent graphic standards make drawings legible and professional. Key conventions:
| Element | Line Weight | Convention |
|---|---|---|
| Wall, full height (cut through) | Heavy (0.35–0.50 mm) | Solid, often poche-filled |
| Wall, partial height / pony wall | Medium (0.25 mm) | Solid |
| Objects below cut plane (furniture) | Light (0.15–0.18 mm) | Solid or dashed |
| Objects above cut plane (overhead) | Dashed (0.15 mm) | Dashed line |
| Hidden elements | Dashed (0.25 mm) | Short dash |
| Centerlines | Dash-dot (0.25 mm) | Long dash, dot, long dash |
| Dimension lines | Thin (0.13 mm) | With tick marks at ends |
| Leaders | Thin (0.13 mm) | Arrow or dot terminator |
Symbols and Notation
- North arrow: on every plan, indicating true or project north
- Scale notation: graphic bar scale and ratio (e.g., 1/4 inch = 1 foot)
- Grid system: alphanumeric column grid matching architectural drawings
- Section marks: circle with two letters or numbers, pointing in section direction
- Elevation marks: circle with single letter, referencing the elevation sheet
- Door tags: number keyed to door schedule
- Window tags: letter or number keyed to window schedule
Communicating Design Intent
The test on the IDFX exam is: does the drawing set communicate full design intent? A contractor should be able to price and build the project from the drawings without guessing. If a finish, dimension, or relationship is not shown, it is a gap. The designer reviews the set for completeness before issuing:
- Every wall dimensioned on plan and elevation
- Every finish identified on the finish plan and schedule
- Every lighting fixture located on the RCP with type callout
- Every millwork piece shown in plan and elevation
- Every accessible element (clear floor space, turning space, grab bars) dimensioned
- Every code-required element (exit signs, fire extinguisher locations) shown
Drawing Set Relationships
The drawings are not independent — they are a coordinated set. A light fixture on the RCP must not land above a partition wall on the floor plan. A finish on the finish plan must align with the wall on the elevation. A soffit shown on a section must match the ceiling height on the RCP. Coordination — checking that every drawing agrees with every other — is the final step before issuing the set.
What does a reflected ceiling plan (RCP) show, and why is it 'reflected'?
On a floor plan, what line weight convention is used for furniture and other objects below the standard cut plane (approximately 4 feet above the floor)?
In a preliminary lighting layout on an RCP, why should perimeter fixture rows be placed parallel to windows and switched on separate zones from interior rows?