Structured 10-stage methodology for planning bathroom layouts with focus on ergonomics, functionality, and safety. Use when planning bathroom furniture placement, optimizing bathroom space, arranging bathroom fixtures (toilet, sink, bathtub, washing machine), or solving bathroom layout challenges. Applicable to large bathrooms (10+ square meters) with flexible plumbing.
This skill provides a systematic 10-stage algorithm for planning bathroom layouts from scratch. It emphasizes ergonomics, functionality, and safety as primary considerations, helping you make data-driven decisions about furniture placement in large bathrooms where plumbing can be flexibly routed.
The methodology follows an "anchor points" approach: start with objects that are most expensive to move (fixtures tied to plumbing), then fill in flexible elements around them.
Core Workflow
The 10-stage process:
Gather baseline information - Measure room, locate utilities, identify constraints
Define fixed points - Identify which objects are hardest to move
Divide into functional zones - Wet, sanitary, hygiene, utility zones
Apply ergonomic rules - Distances, heights, trajectories, safety
Optimize storage - Organize by frequency of use
Create layout variants - Generate 2-3 different arrangements
Evaluate and select - Score variants against criteria
Related Skills
Detail the solution - Specify exact dimensions and materials
Field verification - Test with tape on floor before construction
Flexibility and adjustments - Allow for 10% deviation during implementation
Stage 1: Gather Baseline Information
Measure and Document
Physical boundaries:
Exact room dimensions (length × width × height)
Door location (opening direction, clearance needed)
Heated towel rail location (if connected to heating system)
User parameters:
Who uses the bathroom (height, physical characteristics, left/right-handed)
Special needs (elderly, children, mobility limitations)
Tip: Use the measurement template in assets/measurement_template.md to ensure nothing is missed.
Stage 2: Define Fixed Points
Priority Logic
Objects ranked by cost to relocate:
Level 1 - Immovable objects:
Toilet - Must be very close to sewage standpipe (1-1.5m maximum)
Bathtub/shower - Needs drainage with proper slope, can be up to 3-5m from standpipe
Washing machine - Requires water + sewage + electrical outlet
Decision criterion:
What does it cost to move an object 1 meter?
Toilet: Expensive (complex sewage routing)
Bathtub: Medium (needs slope, but pipe can be longer)
Washing machine: Medium (water + electricity)
Sink: Cheap (flexible hoses)
Cabinets/bench: Free (not tied to utilities)
Start planning with the most expensive items first.
Stage 3: Divide into Functional Zones
Four Primary Zones
Wet zone (bathtub/shower):
Requires waterproofing
Good lighting needed
Steam ventilation required
Minimum 70 cm clearance to other objects
Sanitary zone (toilet):
Privacy desirable (visual separation or niche)
Access requirements: 60 cm in front, 25 cm on each side
Should not be the first thing visible from entrance
Hygiene zone (sink):
The "command center" - most activity happens here
Mirror, lighting, electrical outlet
Easy access to storage (toothbrushes, cosmetics)
Minimum 30 cm from toilet
Utility zone (washing machine, storage):
Can be farther from center
Machine noise should not disturb
Access for loading/unloading laundry
Stage 4: Apply Ergonomic Rules
Movement Trajectories
From door to each object: free passage minimum 70 cm wide
"Action triangle": sink → toilet → bathtub (should be convenient)
No trajectory intersections (e.g., open door shouldn't block toilet access)
Critical Distances
In front of sink: 70-90 cm (to bend over)
In front of toilet: 60 cm minimum
In front of bathtub: 70-100 cm (for drying, dressing)
In front of washing machine: 90-100 cm (to bend with laundry)
Installation Heights
Sink: 80-85 cm from floor (or customized to user height)
Mirror: lower edge at 120 cm (to see face)
Shelves above sink: 170-190 cm (easy reach)
Towel hooks: 140-150 cm (comfortable height)
Light switches: 90 cm from floor
Dominant Hand Considerations
If user is right-handed → towel to the right of sink
Faucet more convenient on right or center
Bench next to bathtub on the exit side
Safety Requirements (Your Priority)
No slippery zones in movement paths
Electrical outlets minimum 60 cm from water sources
Heated towel rail should not burn (not closer than 60 cm to toilet)
Sharp furniture corners not at child's head level
Anti-slip flooring in wet zone
Stage 5: Optimize Storage
Organization by Frequency of Use
Very frequent (multiple times daily):
Towels → hooks/towel rail near bathtub and sink
Toothbrushes, soap → sink countertop or wall shelf
Toilet paper → holder 60-70 cm from floor, within arm's reach
Frequent (once daily):
Shampoos/gels → shower shelf or bathtub niche at 100-120 cm height
Hairdryer, cosmetics → drawer under sink or wall cabinet
Infrequent (weekly):
Supplies (cleaning products, paper) → lower cabinet or closed niche
Laundry detergent → next to washing machine
Access criterion:
Can you reach the item without moving away from where you're using it?
Storage Types
Under sink - Cabinet for cleaning supplies (doors hide clutter)
Above sink - Mirror cabinet for daily cosmetics
Tall cabinet - For towels and supplies (saves floor space)
Open shelves - For decorative items and plants (decor + function)
Wall niche - If construction allows (doesn't steal floor space)
70% Rule:
Don't fill storage more than 70% - leave room for maneuvering and new items.
Stage 6: Create Layout Variants
"From Anchor" Method
Step 1: Draw room plan to scale (graph paper: 1 square = 10 cm)
Step 2: Mark "anchor points":
Door (with opening radius)
Water supply and sewage standpipes
Windows
Ventilation
Step 3: Place toilet (most demanding):
Maximum 1.5m from sewage standpipe
Not visible immediately from entrance (if possible)
60 cm clear in front, 25 cm on sides
Step 4: Place bathtub:
Often along long wall (standard 170 cm)
Drainage can be 3-5 meters from standpipe
Account for curtain or partition space
Step 5: Sink between or opposite them:
"Command center" - in center of activity
Mirror should be well-lit (window or fixtures)
Can have cabinet or washing machine underneath
Step 6: Washing machine:
Where there's access to water + sewage + outlet
Often under sink countertop or adjacent
Noise - away from bedroom (if shared wall)
Step 7: "Soft" elements (cabinets, bench):
Fill remaining space
Bench next to bathtub (to sit after shower)
Cabinets where space remains, but within reach
Generate 2-3 Variants
Variant A: Classic (bathtub along wall, everything else opposite)
Variant B: Zoned (toilet in niche/behind partition, bathtub and sink in open zone)
Variant C: Island (if space allows - sink on island, rest around perimeter)
Stage 7: Evaluate and Select
Evaluation Questions for Each Variant
Functionality:
Can you open door without hitting furniture?
Can you freely approach each object?
Is there space to dry off after shower/bath?
Can you use sink when someone is in bathtub?
Is there adequate space for loading washing machine?
Ergonomics (Your Priority):
Are there unnecessary steps between related actions?
Is towel within arm's reach from bathtub and sink?
Is mirror at comfortable height and well-lit?
Can you easily reach frequently used items?
Will you need to bend/stretch in awkward positions?
Safety:
Is there risk of slipping on wet floor when exiting bathtub?
Are outlets away from splashes?
Is there enough space to avoid hitting corners?
Is floor level without thresholds (tripping hazard)?
Is there something to grab when exiting bathtub? (handrail or wall)
Technical Feasibility:
Does pipe routing fit the budget?
Is there sufficient drainage slope?
Is water pressure adequate for all fixtures?
Can electricity be safely routed to washing machine?
Future-proofing:
What if a child arrives? (need space for baby bathtub)
What if elderly relative moves in? (need handrails, shower seat)
Is layout easy to change without redoing plumbing?
Scoring Method
Rate each variant:
Convenience: 1 (inconvenient) to 10 (excellent)
Ergonomics/Safety: 1 to 10
Implementation cost: 1 (expensive) to 10 (cheap)
Aesthetics: 1 to 10
Multiply "Convenience" and "Ergonomics" scores by 2 (your priorities).
Variant with highest total score is optimal.
Tip: Use the evaluation checklist in assets/evaluation_checklist.md for systematic scoring.
Stage 8: Detail the Solution
After Selecting Variant - Specify
Technical dimensions:
Exact location of each object (distances from corners)
Installation heights (sink, mirror, shelves)
Furniture dimensions (to order or purchase)
Plumbing plan:
Water supply schematic (pipe taps)
Sewage schematic (diameters, slopes)
Electrical layout (outlets, switches, fixtures)
Ventilation (exhaust location)
Shopping list:
Fixtures (with exact model numbers and dimensions)
Furniture (dimensions, color, material)
Faucets, siphons, flexible hoses
Mounting hardware (for wall cabinets, mirror)
Accessories (hooks, holders, soap dishes)
Lighting plan:
General lighting (ceiling, is one fixture enough?)
Task lighting at mirror (sconces or mirror lighting)
Night light or emergency lighting
Switches (where convenient - by door or near mirror)
Stage 9: Field Verification
Before Starting Renovation
Painter's Tape Method:
Tape floor outlines of all objects at full scale
Walk through room, simulating real actions:
Enter, close door
"Approach" sink, sit on "toilet"
Imagine exiting bathtub - where do you step?
Try "loading" washing machine
Is it comfortable? Are there places where knees bump, head hits?
Temporary Furniture Method:
If possible - bring cardboard boxes sized like future furniture into room. Live with it for a day or two, observe comfort level.
Third-party Review:
Show plan to a familiar plumber or designer - fresh eyes will catch mistakes.
Stage 10: Flexibility and Adjustments
During Renovation
10% Deviation Rule:
Allow ability to shift objects 10-15 cm in any direction:
Don't tile walls BEFORE installing bathtub (what if it doesn't fit)
Make pipe outlets with extra length
Place outlets so extension cord can be used if needed
Triggers for Plan Changes:
If during process you discover:
Standpipe not where expected (sometimes behind a box)
Water pressure weaker (need pump or relocate fixtures)
Found hidden niche (can use for storage)
Budget decreased (simplify solution)
Don't fear corrections - better to change during rough-in than live with inconvenience.
Decision Principles
When in Doubt
"Occam's Razor":
If two solutions are roughly equal - choose simpler and cheaper.
"Reversibility Rule":
If it's easy to redo - don't fear mistakes. If irreversible (pipes in concrete) - verify three times.
"Future Me Rule":
Ask yourself: "In 5 years, will I be glad I made this decision?" If yes - do it.
"Testing Rule":
Any decision that can be verified in advance (tape, boxes, 3D planner) - MUST be verified. Assumptions are the enemy of comfort.
Common Mistakes to Avoid
❌ Forgot about door - it opens and takes up space
❌ Sink too close to wall - hard to clean floor, elbows hit wall
❌ Toilet first thing visible from entrance - psychologically unpleasant
❌ Washing machine blocks passage - need to squeeze through
❌ Heated towel rail above toilet - burns back
❌ Mirror opposite window - glare, can't see face
❌ All cabinets wall-mounted - psychologically oppressive, "looming"