Interior Lighting Layout Diagram

Revised 2026-06-05 — corrected orientation + longitudinal bay layout

This diagram was rebuilt to fix two errors in the original: (1) the door wall is the 40’ wall (so 40’ = width, 24’ = depth — the old version had this flipped), and (2) vehicle-bay lighting now runs front-to-back, one run per bay (3 × 5) instead of cross-bay rows. See Decisions Log 2026-06-05 and the matching figure in Interior Lighting Plan.

Garage Dimensions & Orientation

Size: 40’ (width, door wall) × 24’ (depth) × 10’ (height) Total Area: 960 sq ft Ceiling Height: 10 feet Doors: three overhead doors on the 40’ (south/front) wall → three bays ≈ 13’-4” wide, each ~24’ deep Finished interior depth: ~23’ (24’ less wall framing + drywall) — sets the fixture-run length

Lighting Layout (Top-Down View)

Vehicle-bay fixtures run front-to-back down each bay (along the 24’ depth), one run per bay, each rear-fed from a single ceiling outlet on the north wall:

Green = Barrina runs (5/bay). White circles = one rear-wall outlet per bay, each feeding a single 5-fixture chain toward the doors. Dashed = the dedicated 20A bay-lighting feed along the north wall. Workbench (rear/north) and lift (Bay 3) have their own zones.

        N — REAR WALL (workbench) — lighting outlets here
   ┌──────────────┬──────────────┬──────────────┐
   │  ⊙ O1        │  ⊙ O2        │  ⊙ O3        │ ← rear-wall feed (1 outlet/bay)
   │   ▌ F1 (rear)│   ▌ F6       │  ▌ F11       │
   │   ▌ F2       │   ▌ F7       │  ▌ F12       │
   │   ▌ F3       │   ▌ F8       │  ▌ F13       │   single 5-fixture
   │   ▌ F4       │   ▌ F9       │  ▌ F14       │   chain per bay
   │   ▌ F5(front)│   ▌ F10      │  ▌ F15 +lift │
   └──────────────┴──────────────┴──────────────┘
        S — FRONT (40' wall: 3 doors + openers, own circuit)

Detailed Zone Layouts

Zone 1: Vehicle Bays — 15 fixtures (3 runs × 5, flush mount, front-to-back)

Each bay gets one longitudinal run of 5 fixtures (20’), dropped into the ~23’ interior depth. The run is rear-fed: a single ceiling outlet on the north (rear) wall at the bay centerline feeds one continuous chain running front-to-back toward the doors — one cord per bay.

Bay	Fixtures (rear→front)	Feed
Bay 1 (west)	F1–F5	Outlet O1, rear wall, bay centerline
Bay 2 (center)	F6–F10	Outlet O2, rear wall, bay centerline
Bay 3 (east, lift)	F11–F15	Outlet O3, rear wall, bay centerline

• Mounting: flush to the truss bottom chord that runs down each bay centerline (chords span front-to-back) — one straight 20’ line, no crossing members
• Why rear-fed: keeps all lighting outlets on the north wall, clear of the south-wall door tracks, openers, and front-wall outlets (those stay on the ceiling-door circuit). Clean north/south separation; ignores the door-lift-track zone entirely.
• Why 5/bay: six fixtures = 24’, which overruns the ~23’ interior depth; five (20’) fits cleanly
• Front margin: the chain ends ~1–2’ short of the front wall — the door-panel parking zone anyway, so nothing useful is lost; cars park nose-in, so the engine end stays lit
• Total: 15 fixtures, 3 runs, 3 ceiling outlets on the dedicated 20A bay circuit

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Zone 2: Workbench/Tool Area (6 Suspension-Mount Fixtures)

Row A (Primary Workbench) — 3 Fixtures:

     [S1] ━━━━━━ [S2] ━━━━━━ [S3]  →  Single outlet (Workbench circuit)
        ↓            ↓            ↓
   ┌────────────────────────────────┐
   │     WORKBENCH (north wall)      │  ← Lights 36-48" above surface
   └────────────────────────────────┘

• S1–S3: suspended over the main workbench (centered on the north/rear wall)
• Height: 36–48” above bench surface (6–7’ above floor) · Spacing: 4–6’ apart
• Connection: linked → single cord to outlet O4

Row B (Tool/Secondary Area) — 3 Fixtures: S4–S6, same pattern, linked → outlet O5.

Total for Workbench: 6 fixtures, 2 linkable groups, 2 outlets (workbench circuit)

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Zone 3: Lift Bay Support (3 Dedicated Task Fixtures)

General light over the lift bay comes from Bay 3’s run (F11–F15) above. Zone 3 adds dedicated task fixtures near the columns on the separate lift-bay circuit, so lift lighting stays up even if the bay circuit is off:

            ┌──── Bay 3 run (F11–F15) overhead ────┐
                       [L1] (flush)   [L2] (flush)
                              [L3] (suspension ↕ 48-60")
                       ╔═══════════╗
                       ║   2-POST  ║
                       ║   LIFT    ║
                       ╚═══════════╝

• L1, L2: flush overhead, general lift-bay fill
• L3: suspension near the columns for undercarriage/detail work (lower than the bench fixtures for access)
• Circuit: lift-bay support 20A · Outlet: O6
• Future: lift-arm underlighting (Zone 4 in the Lighting Plan) is post-lift

Total for Lift Bay: 3 dedicated fixtures (2 flush, 1 suspension) — no longer double-counted with the bay runs

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Fixture Summary by Zone

Zone	Flush Mount	Suspension Mount	Total	Outlets Needed
Vehicle Bays (3 runs × 5)	15	0	15	3 (ceiling duplexes, bay mid-depth)
Workbench	0	6	6	2 (bench height)
Lift Bay (dedicated)	2	1	3	1 (mixed)
TOTAL	17	7	24	6

Fixture budget: the Barrina 20-pack on hand covers the 15 bay fixtures + 5 toward Zones 2/3; ~4 more complete the workbench/lift zones.

Electrical Outlet Placement

Vehicle Bay Outlets (Bay Lighting Circuit: 20A dedicated)

Outlet	Location	Serves
O1	Ceiling, rear (north) wall, Bay 1 centerline	F1–F5 (single chain, rear→front)
O2	Ceiling, rear wall, Bay 2 centerline	F6–F10 (single chain)
O3	Ceiling, rear wall, Bay 3 centerline	F11–F15 (single chain)

All three sit on one NM-B run along the rear wall on the dedicated 20A bay circuit. (Box = 4” square + mud ring per the 2026-06-03 box-fill decision; sized to also host the Zone-1 Shelly at one of the rear boxes.)

Workbench Outlets (Workbench Circuit: 20A)

• O4 — wall/ceiling above workbench Row A → S1–S3
• O5 — above secondary work area Row B → S4–S6

Lift Bay Outlet (Lift Circuit: 20A)

• O6 — near lift column / rear → L1–L3

Installation Sequence

Phase 1: Electrical Rough-In

1. Install the 3 bay-lighting outlets (O1–O3) on the rear (north) wall at each bay centerline, on the dedicated 20A circuit (one NM-B run along the rear wall); workbench (O4–O5) and lift (O6) per their circuits
2. Install smart-switch boxes (see Smart Control Zones)

Phase 2: Ceiling/Truss Marking

1. Identify the truss bottom chord running down each bay centerline
2. Mark the 5 fixture positions along it from the rear outlet toward the front, ending ~1–2’ short of the front wall (clear of the door-panel parking zone)
3. Verify chord spacing (24” O.C.) and adjust fixture positions to land on the chord

Phase 3: Flush-Mount Installation (Vehicle Bays)

1. Bay 1: mount F1–F5 to the chord; link as a single chain and plug the rear fixture’s cord into O1
2. Bay 2: F6–F10 → O2 · Bay 3: F11–F15 → O3
3. Dress the one cord per bay to its rear outlet

Phase 4: Suspension-Mount Installation (Workbench)

1. Eye bolts into the chords over the bench; hang S1–S3 (Row A) → O4, S4–S6 (Row B) → O5 at 36–48” above the bench

Phase 5: Lift Bay Installation (post-lift)

1. Install L1–L2 flush + L3 suspension near the columns → O6; coordinate with the lift footprint

Phase 6: Testing & Adjustment

1. Energize, test every fixture and link, verify coverage, configure smart controls

Coordination Notes

With Compressed Air System

• Coordinate fixture lines with the ceiling air-line routing; leave clearance for drops/fittings — see Compressed Air System Shopping List

With HVAC System

• Avoid placing fixtures directly in front of the wall-mounted mini-split air handlers — see HVAC Strategy

With 2-Post Lift

• Bay 3’s run (F11–F15) and the dedicated lift fixtures must clear the lift posts/arms when raised; confirm against the chosen lift’s footprint

Smart Control Zones

Switch topology decided 2026-04-20 — see Electrical Planning: Switch Topology.

Zone	Outlets	Relay	Physical control
1 — Vehicle Bays (walk-through)	O1, O2, O3	Shelly Plus 1PM	3-way: entry door + stairwell bottom
2 — Workbench (task)	O4, O5	Shelly Plus 1	single-pole at bench
3 — Lift Bay (task)	O6	Shelly Plus 1	single-pole near lift; optional lift-activation auto
4 — Stairwell (safety)	stairwell fixture	Shelly Plus 1PM	3-way: bottom + top (hardwired, HA-independent)

Scenes

“All On” · “Work Mode” (workbench + lift) · “Bay Mode” (vehicle bays) · “Away” (all off)

Switch Location Markers

See Physical Switch Locations:

• SW-E entry door (bay 3-way A + SLS soffit) · SW-SB stairwell bottom 2-gang (bay 3-way B + stairwell 3-way A) · SW-ST stairwell top (stairwell 3-way B) · SW-L loft (single-pole) · SW-W workbench (single-pole) · SW-LB lift (single-pole)

Mounting Hardware Checklist

Included with Fixtures

• Mounting screws (flush mount, per fixture)
• Hanging chains/cables (per suspension fixture)
• Linking cables (48” each) and power cords (one chain / one cord per bay with the rear feed)

Additional Hardware Needed

• Ceiling hooks/eye bolts for the 9 suspension fixtures (workbench + lift) — 1/4” × 3”, 50+ lb rating
• Cable-management clips for the linking cables
• Stud finder (locate truss chords) and a level

References

• Main Lighting Plan: Interior Lighting Plan
• Electrical Planning: Electrical Planning
• Draft layout options (Option A vs B): printable/lighting-layout-options.html
• Compressed Air System: Compressed Air System Shopping List
• HVAC Coordination: HVAC Strategy

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Document created: 2025-11-17 Last updated: 2026-06-05 — corrected door-wall orientation (doors on 40’ wall) and rebuilt Zone 1 as longitudinal per-bay runs (3 × 5); fixture IDs renumbered F1–F15 + L1–L3. Status: Planning phase - ready for installation coordination