residential-cad

name	residential-cad
description	Room standards, zoning, and layout rules for residential buildings — houses, apartments, villas, flats, bungalows, duplexes, row houses, independent houses, 1BHK, 2BHK, 3BHK, 4BHK, penthouse, farmhouse, cottage, townhouse, studio apartment, granny flat, annexe. ALWAYS use this skill when the user mentions any residential dwelling. Composable with cad-core for coordinate generation.
version	1.0
composable_with	["cad-core"]

Residential Layout Skill

Residential layouts prioritize livability — clear zoning between public, private, and service areas; efficient wet-area clustering for plumbing; and compliance with Indian NBC minimum room sizes. Every room has strict minimum dimensions that MUST be met.

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REFERENCES TO LOAD

• Always load: references/room_standards.md — minimum sizes for every residential room type
• Always load: references/floor_planning.md — ground/upper/terrace floor composition
• Load for worked example: references/example_layout.json — complete 2BHK reference

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DOMAIN-SPECIFIC RULES

RULE R1 — Zoning.

• PUBLIC zone (living, dining, entrance foyer) MUST be near the main entrance, typically at the front (south side) of the plot.
• PRIVATE zone (bedrooms, study) MUST be away from the entrance, toward the back or upper floors.
• SERVICE zone (kitchen, utility, servant room) MUST be accessible from dining but away from bedrooms.

RULE R2 — Wet area clustering. WET areas (kitchen, bathrooms, utility) MUST be clustered together for efficient plumbing routing. Do NOT scatter bathrooms across opposite corners of the plot.

RULE R3 — Kitchen-dining adjacency. Kitchen MUST be directly adjacent to the dining room. They must share a wall or be separated by only the wall_thickness gap.

RULE R4 — Master bedroom attached bathroom. If space permits, the master bedroom MUST have an attached bathroom accessible through a door on the bathroom's wall facing the bedroom.

RULE R5 — Staircase consistency. For multi-story buildings, the staircase MUST be at the same x position and same width on EVERY floor. Minimum clear width 900mm per NBC.

RULE R6 — Corridor connectivity. Every room must be reachable from the entrance through doors. Corridors connect rooms that don't share direct walls. Avoid rooms accessible only by passing through another private room.

RULE R7 — At least one bathroom per floor.

RULE R8 — Entrance foyer connects to living room.

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UNKNOWN ROOM HANDLING

If the user requests a room not in room_standards (e.g., "meditation room", "home theater"), estimate its size using domain knowledge:

• Use the closest comparable room as a baseline
• Set estimated: true on the room
• Add the room name to flagged_estimated_rooms in your output
• Never make an unknown room smaller than 2000×2000mm

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LAYOUT PRINCIPLES

Ground Floor Typical Composition

• Parking/garage OR entrance foyer at front
• Living room + dining room (open or semi-open)
• Kitchen (adjacent to dining)
• 1 bedroom with attached bathroom (optional for guest/elderly)
• Staircase (if multi-story)
• Utility/store room

Upper Floor Typical Composition

• Master bedroom with attached bathroom
• 2–3 additional bedrooms
• Common bathroom
• Study room/family room (space permitting)
• Balcony off master bedroom or along front
• Staircase (same position as ground floor)

Terrace Floor

• Terrace/open area (most of footprint)
• Utility room for water tank/AC units
• Optional covered sit-out area
• Staircase head room

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CODE COMPLIANCE REFERENCES

IBC Section 1107 — Accessibility (Multi-Family):

• 4+ dwelling units: ALL units must be Type B (basic mobility features)
• 2% of units (min 1): Type A (fully accessible — 32" clear doors, 60" turning in bathrooms)
• Accessible units MUST be dispersed among unit types and floors — do NOT cluster on one floor
• Visitability: accessible path from parking to unit entrance (slope max 1:12)

ANSI A117.1 — Dimensional Requirements:

• Type A: door clear width 815mm (32"), bathroom turning diameter 1525mm (60")
• Type B: door clear width 815mm, 36" halls, reinforced walls for grab bars
• Kitchen: 1016mm (40") clearance between opposing counters

IBC — Egress:

• Max travel distance within dwelling: 38m (125ft) sprinklered R-2
• Two exits required when > 4 stories or > 16 dwelling units
• Exit stair width: min 1100mm (44") serving > 50 occupants

Sound Transmission (IBC 1207):

• STC 50 minimum between dwelling units (airborne)
• IIC 50 minimum between floors (impact)
• Note: affects wall placement between units

Indian NBC 2016 (for Indian projects):

• Habitable room: min 9.5m² with min 2.4m dimension
• Kitchen: min 5.0m² with min 1.8m width
• Bathroom: min 1.8m²
• Corridor: min 1.0m width
• Staircase: min 900mm clear width, max 150mm riser, min 250mm tread