LDD-29 · Gym Architectural Systems

Status: 🟡 LOCKED DESIGN INTENT v1.0 — Peter's 2026-05-17 revised synthesis email (supersedes 2026-05-16 draft, which omitted the gym athletic floor system). Unifies seven focused gym LDDs (04, 08, 12, 22, 25, 26, 27) under a single "calm industrial Great Hall" thesis. Several specs need engineer review before promotion to 🟢 — see Open items.

v1.0 supersede note (2026-05-17): Peter's revised email adds three new sections — §25 Athletic Floor System (radiant slab + rubber underlayment + poured urethane, motivated by lifelong joint comfort and his back), §26 Athletic Floor Finish (matte/satin-matte only), §27 Permanent Athletic Striping Philosophy (NCAA half-court basketball + beach volleyball). Subsequent cards renumbered +3.

Editorial note: Peter's email used cross-ref labels that don't match this set's actual LDD numbering (e.g., he wrote "LDD-15 Lighting" when this set's LDD-15 is the Mechanical Room — actual lighting is LDD-08). Corrected silently throughout this document; full translation table in the Cross-references (Peter's labels mapped to this set) section below.

One-line intent

The gym is a transformable athletic Great Hall — grounded and tactile below the 16' AFF datum, luminous and infrastructural above it — integrated into the home's architectural language rather than functioning as a sports outbuilding.

Design intent · AI render

FPO · AI render

Architectural intent render of the gym Great Hall — looking west toward the hero wall at sunset. For Position Only: AI-generated from the prompt below, regenerated as image models improve. Click to enlarge.

Architectural interior rendering of a transformable athletic Great Hall — a 60' × 60' × 24' gymnasium integrated into a luxury barndominium residence (not a sports facility). Wide-angle photoreal view looking west toward the hero wall, captured at golden-hour sunset. 16:9 aspect. No people in frame.

Spatial hierarchy. The room reads as two stacked zones divided by an implicit 16' AFF datum. The LOWER zone (0–16') is grounded, calm, tactile — medium warm-gray wall fields, soft charcoal athletic surfaces, restrained dark metal trim, warm white-oak accents. The UPPER zone (16' to roof) is luminous and infrastructural — exposed pre-engineered metal building (PEMB) structure in dark charcoal, intermittent suspended acoustic cloud panels (charcoal, 4'×8' modules in three N-S strips), four low-profile dark-bronze destratification fans (small residential-commercial hybrids, NOT giant warehouse HVLS fans), and runs of linear LED fixtures mounted tight to the structure.

West hero wall (background of frame). A single calm continuous architectural plane in medium warm gray. At the center: a partially exposed structural PEMB steel column running floor to roof — this column is the visual anchor and the basketball hoop centerline datum. Symmetrically arranged around the column are four clerestory windows in two horizontal rows (two per row, 24" tall × 16' wide each, dark bronze thermally broken commercial glazing). Warm sunset light pours through the clerestories, glowing across the upper wall. Beneath the lower-row clerestories sit two small white high-wall mini-split indoor units, symmetrical left and right of the column axis. Centered on the column at mid-height: a wall-mounted commercial basketball backboard with 72" glass and breakaway rim, projecting ~6'-0" from the wall on a clean dark structural-steel subframe (the "hoop spine"). An 8'-wide soft-charcoal athletic wall pad mounted ~1' above floor, centered behind the hoop.

North wall (right side of frame). Floor-to-ceiling dance-studio-quality safety-backed mirrors framed in restrained dark metal trim, with double horizontal ballet barres at standard heights. Calm reflective surface, NOT a sports-facility mirror wall.

South wall (left side of frame). A durable calm rebound surface with acoustic moderation — matte medium-warm-gray finish, no decorative striping, no logos.

East wall (foreground, behind the viewer position). A cantilevered overlook balcony projects from above with a thin vertical steel-rod railing topped by a warm hardwood top rail (looks like reclaimed white oak). The underside of the overlook is dark and discreet, with concealed channels for retractable athletic protection nets.

Floor. Matte poured-urethane athletic floor in medium warm-gray over a vulcanized rubber underlayment, with permanent NCAA half-court basketball striping (primary, slightly visually dominant) and beach volleyball court striping (secondary, lighter overlay) in restrained charcoal-gray. Two flush metal floor sleeve covers visible along the volleyball net centerline. No gloss, no logos, no center-court branding.

Ceiling. Visible PEMB steel structure (primary purlins, secondary framing) in dark charcoal, NOT concealed. The three N-S infrastructure bands read as orderly longitudinal organization — acoustic clouds, linear lighting, and fans coordinated within them. Open in between bands so the structure breathes. No drop ceiling. No grid tile.

Lighting mood. Layered and warm. Primary athletic ceiling lighting dimmed to atmospheric setting, broad diffused glow from the linear LED runs. Concealed upper-perimeter indirect cove glow at the wall/ceiling junction — a faint luminous datum continuing around the room. Small-scale industrial wall sconces on north/south/west walls aligned at a single height datum, casting warm pools. Subtle low-level indirect glow at the wall/floor transition. The dominant light source is the golden sunset glow through the four west clerestories.

Material palette. Medium warm-gray wall fields, soft charcoal athletic surfaces and acoustic clouds, darker charcoal upper infrastructure, restrained dark-bronze metal systems, warm white-oak accents. No bright sport colors. No glossy institutional finishes.

What this is NOT (critical). Do NOT render as: a warehouse gym, an institutional school/rec center, an arena, a boutique wellness studio, a luxury sports theater, or a commercial fitness facility. NO decorative sports branding. NO team logos or scoreboards. NO advertising graphics. NO HVLS warehouse fans. NO exposed triangulated arena-style trusses. NO visible fluorescent strip lighting. NO bright primary colors. NO glossy gym flooring. NO Christmas-tree-of-pendants chandelier composition.

Style direction. Professional architectural visualization, photoreal, evenly exposed. Calm and quiet mood. Neutral camera with slight elevation (~5'-6' eye-level), wide angle equivalent to ~24mm full-frame, showing ceiling structure and floor surface together. Sharp focus throughout, no shallow depth-of-field. Should feel like the cover image of an architecture monograph, not a sports-facility marketing brochure.

Why this matters

The gym already had seven separate LDDs covering its surfaces and subsystems. What was missing was a single doc that says what kind of room this is. Without it, each subsystem gets value-engineered against its own efficiency (cheaper fans, deferred nets, simpler clerestory) instead of against the overall calm-vs-athletic balance. Cumulatively those small choices turn the gym into "warehouse with hoops." LDD-29 is the rule the focused LDDs are tested against during VE.

Locked decisions

Open items / requires engineer review

• Hoop Spine structural sizing (decision #18) — engineered steel subframe + tie to PEMB column + slab anchorage. Structural engineer (Pennoni or Becker Morgan per contractor shortlist). Single largest engineering gap in LDD-29.
• 6' rim projection from west wall (decision #18) — final hardware vendor + retraction kinematics that clear the lower clerestory band when parked up.
• Four-clerestory dimensional reconciliation with LDD-04 (decision #16) — confirm 24"×16' module aligns with PEMB girt rhythm + IMP joint rhythm before glazing order.
• Destratification fan model selection (decision #10) — quiet, low-speed, dark finish. Candidates: Big Ass i6 (charcoal), Hunter Industrial Mariner, MacroAir AirVolution-D. Avoid 12'+ HVLS fans.
• Overlook deployable net design language (decision #31) — coordinate with LDD-25 mirror-wall net so they read as one infrastructure family.
• Overlook railing top-rail wood source (decision #30) — harvested site hardwood feasibility + milling + drying vs. commercial hardwood substitute.
• Urethane gym floor vendor + warranty (decision #25) — confirm vendor at bid (Robbins Pulastic, Mondo, Junckers Connect, or similar pro-grade poured urethane over vulcanized rubber). Verify bonded warranty covers radiant slab thermal cycling and confirm coordination with LDD-24 spec.
• NCAA half-court basketball striping geometry (decision #27) — confirm 28' × 47' college half-court layout, hoop centerline alignment with PEMB column, and coexistence/visual hierarchy testing with beach volleyball striping. Sample mock-up on a 4'×4' urethane test pour before full pour.
• LDD-31 (destratification fans) + LDD-32 (overlook edge + deployable nets) — flagged as spinoffs. Engineering specs deserve their own focused LDDs before structural drawings bid. (Previously slotted as LDD-30/31; bumped because LDD-30 is now Central Mechanical Core Master Strategy.)

Cross-references (Peter's labels mapped to this set)

Peter's 2026-05-17 email (and the prior 2026-05-16 draft) used cross-ref labels that don't match the actual LDD numbering. Mapped here:

Cross-references (canonical, this LDD ↔ others)

• → LDD-01 PEMB structural — PEMB center column = hoop centerline datum (decision #14); girt rhythm coordinates with clerestory schedule (decision #16).
• → LDD-04 west gym hero wall — focused LDD; decisions #13–#21 unify around its clerestory + hoop + finish + mini-split spec.
• → LDD-05 HVAC system — destratification fans (decision #10) interact with radiant slab + mini-split performance.
• → LDD-08 lighting framework — four-tier gym hierarchy (decisions #5–#9) specifies the "Gym" scene of LDD-08's project-wide layered system.
• → LDD-12 exposed ceilings — three N-S infrastructure bands (decision #3) refine LDD-12's general rule for the gym specifically.
• → LDD-22 basketball hoop — decision #18 introduces the Hoop Spine structural philosophy refining LDD-22.
• → LDD-24 flooring — gym floor build-up (radiant slab + rubber underlayment + poured urethane) per decision #25; striping spec per decisions #26–#27. Materials + cost carried by LDD-24; architectural intent + body-comfort rationale here.
• → LDD-25 north gym ballet wall — focused LDD; decision #22 unifies. Net design language coordinates with decision #31.
• → LDD-26 south gym rebound wall — focused LDD; decision #23 unifies. 16' AFF transition datum aligns.
• → LDD-27 acoustic clouds — clouds are layer 6 of the gym ceiling per decision #11.
• → LDD-18 interior materials — palette (decision #34) coordinates with project-wide material direction.

Cost drivers

LDD-29 itself adds no line items — it's an organizational intent LDD. The cost impact is the sum of its constituent focused LDDs (04, 08, 12, 22, 25, 26, 27) plus three new gym subsystems not in any prior LDD:

• Destratification fans (decision #10) — 4 fans, quiet residential-commercial hybrid: $1.2–2.5K per fan × 4 = $5–10K including controls + install.
• Overlook deployable protection nets (decision #31) — three motorized zones, concealed housing: $10–22K.
• Overlook railing system (decision #30) — 35'+ thin steel rod balustrade + hardwood top rail: $6–16K depending on hardwood source.

Likely-case rollup for the three NEW gym subsystems: $21–48K on top of the existing LDD-04/08/12/22/25/26/27 budgets.

Athletic floor + striping (§25–§27): ~$16–30K poured urethane + ~$1.5–4K court lines are already attributed to LDD-24 and were in the project waterfall before this revision. LDD-29 §25–§27 add architectural intent + body-comfort rationale, not new dollars.

Air-gap concerns

1. The "calm industrial Great Hall" intent must survive value engineering. The hardest pressure on this LDD is the GC's first VE pass — fans get cheaper, nets get deferred, the hoop spine collapses back into the wall, clerestories shrink, the overlook rail becomes vinyl. Each one independently sounds reasonable; cumulatively the gym becomes "warehouse with hoops." Review every gym VE proposal against LDD-29 explicitly — not against the affected sub-LDD in isolation.
2. Two new "design study" subsystems (overlook rail + deployable nets) are riding on LDD-29 without their own LDDs. Fine for v1.0 LOCKED INTENT, but those decisions will get challenged at bid time. Recommend spinning out LDD-31 (destratification fans) + LDD-32 (overlook edge + deployable nets) before structural drawings go out for bid.
3. Hoop Spine + PEMB center column relationship (decision #18) is a real engineering coordination item. The PEMB column is sized for building structural loads, not for ~2,500 lbf cyclic dunk impact. The "supplemental engineered steel" between the hoop and the PEMB column is the load-decoupling layer. Spec with structural engineer explicitly as a vibration-isolated subframe.
4. Four-clerestory dimensional spec (decision #16) must coordinate with LDD-04's "two rows × 24" × 16' modules" exactly. Compatible — 4' sub-modules within the 16' runs are a glazing detail. Final mullion layout coordinates with PEMB girt rhythm at glazing order.
5. The destratification fan count (4) needs verification against gym volume. Gym is ~60' × 60' × 24' ≈ 86,400 ft³. Pick smaller quieter fans (4–6' commercial-residential hybrid) rather than 8–24' HVLS.
6. Overlook deployable nets and LDD-25 mirror-wall net should share design language. Coordinate motor vendor + control + housing detail.
7. "Sprinkler-flexible" (decision #4) is design discipline, not a code waiver. AHJ may require NFPA 13/13R sprinklers regardless. Validate with the New Castle County Department of Land Use at the same time as the Korean BBQ classification question.
8. The "exposed center PEMB column" composition (decision #14) competes with the basketball backboard. Decide which is the default composition — column-exposed or backboard-prominent — and confirm the gym's default visual state matches intended use frequency.
9. Material palette (decision #34) needs coordination with LDD-18 interior materials against actual paint/material chip selections.
10. Floor striping coloration competes with material palette restraint (decisions #27 + #34). Peter's spec is "restrained low-contrast" but the lines must remain "fully athletically legible." Those two priorities pull in opposite directions. Decide the acceptable contrast band at the finishes meeting; spec a 4'×4' urethane sample pour with proposed striping coloration before the full floor pour. Sample also serves as the vendor warranty check (decision #25).

Diagram

Gym plan, ~60' × 60' × 24'. Dashed lines = overhead features (above the 16'-0" AFF datum). Filled square on the west wall = PEMB center column. Click to enlarge.

Asset Pairing

Intent render Stale floor

Generated plan Missing striping

Both assets still explain the Great Hall direction, but both lag the latest floor system. Regenerate the render and update cad/source/gym_plan.py before treating the visuals as current.

Status

🟡 Yellow — LOCKED DESIGN INTENT v1.0. Peter's spec is internally coherent and the Great Hall thesis is correct. Promotion to 🟢 LOCKED v1.1 requires:

1. Hoop Spine structural sizing with structural engineer (decision #18).
2. Four-clerestory dimensional coordination with LDD-04 + PEMB girt rhythm (decision #16).
3. Destratification fan model selection (decision #10).
4. Urethane gym floor vendor + warranty confirmation (decision #25).
5. NCAA half-court basketball striping geometry + beach volleyball coexistence sample (decision #27).
6. Spin-out of LDD-31 (Destratification fans) and LDD-32 (Overlook edge + deployable nets). (LDD-30 is now Central Mechanical Core Master Strategy; the gym spinoffs have been bumped accordingly.)

None of these block bidding the focused LDDs (04/08/12/22/25/26/27); they DO block bidding gym ceiling rough-in, west wall structural detailing, and the gym floor pour.