Rough-In Trades: Plumbing, Electrical, and HVAC
Overview
- Typical Duration: 6-10 weeks
- DIY Difficulty: ★★★★★ (5/5 - Hire professionals)
- Typical Cost: $40,000-$80,000 (2,000 sq ft house)
- When to Hire: Always (requires licensing)
- Required Inspections: Separate inspections for each trade
This is when your house gets its major systems. Three different trades (plumbing, electrical, HVAC) work simultaneously, which requires careful coordination. These are not DIY projects—all require licensed professionals and inspections.
When This Phase Happens
- Must be complete first: Framing inspection passed, roof weathertight
- Can happen in parallel: Window/door installation
- What comes after: Insulation, then drywall
Should You DIY This Phase?
Never DIY These Trades
❌ Electrical - Illegal without license, dangerous, won't pass inspection ❌ Plumbing - Requires license, specialized tools, prone to expensive mistakes ❌ HVAC - Complex calculations, requires certification, warranty issues
My recommendation: Hire all three trades. This is not where you save money through DIY. The risks (code violations, failed inspections, safety issues, insurance problems) far outweigh any savings.
Save your DIY energy for finish work where mistakes are cosmetic, not dangerous.
The Three Trades
Plumbing Rough-In (2-3 weeks)
What gets installed:
- Supply lines (hot and cold water)
- Drain, waste, and vent (DWV) pipes
- Shower/tub drain assemblies
- Toilet flanges
- Washing machine boxes
- Water heater connections
- Exterior hose bibs
CRITICAL: Tubs and shower pans must be set BEFORE plumbing rough-in. The plumber needs them in place to set drains at correct height and location. Order these early—they're often long-lead items (4-8 weeks).
Materials:
- PEX or copper for supply (PEX more common now)
- PVC or ABS for drains
- Cast iron for main stack (sometimes)
Common issues:
- Vent stacks incorrectly sized or placed
- Insufficient pitch on drain lines (needs 1/4" per foot minimum)
- Wrong pipe sizes
- Forgetting cleanouts
Electrical Rough-In (2-3 weeks)
What gets installed:
- Main service panel
- All circuit wiring
- Outlet and switch boxes
- Light fixture boxes
- GFCI and AFCI protection
- Dedicated circuits (kitchen, bathroom, laundry, HVAC)
Code requirements:
- AFCI protection on most circuits (living areas)
- GFCI protection (bathrooms, kitchen, exterior, garage)
- Dedicated 20A circuits for kitchen countertops
- Separate circuits for major appliances
Common issues:
- Insufficient circuits for modern loads
- Boxes placed at wrong heights
- Missing AFCI/GFCI protection
- Inadequate service panel size
HVAC Rough-In (3-4 weeks)
What gets installed:
- Furnace or heat pump
- Air handler
- Ductwork (supply and return)
- Registers and grilles (rough openings)
- Condensate drain lines
- Refrigerant lines (if heat pump/AC)
- Thermostats (wiring only)
Critical factors:
- Proper load calculation (Manual J)
- Adequate return air (often undersized)
- Sealed ductwork (leaks waste energy)
- Correct equipment sizing
Common issues:
- Oversized or undersized equipment
- Inadequate return air
- Leaky ductwork
- Poor duct layout
Coordination Is Critical
Why this phase is complex: Three trades competing for the same space. Electrician wants to run wire where plumber already installed pipe. HVAC ducts block both of them.
Your job as owner-builder:
- Create a clear schedule (who works when)
- Post the schedule on-site
- Hold coordination meetings
- Resolve conflicts quickly
- Don't let trades work on top of each other
Example schedule:
- Week 1-2: Plumber installs main stacks and drains
- Week 2-3: HVAC installs main trunk lines
- Week 3-4: Electrician runs main circuits
- Week 4-6: All three finish rough-ins
- Week 6-8: Inspections and corrections
Materials Needed
Plumbing Materials
| Item | Typical Cost | Notes |
|---|---|---|
| PEX tubing & fittings | $800-$1,500 | For 2,000 sq ft |
| PVC drain pipes | $600-$1,200 | DWV system |
| Valves & fixtures rough-in | $400-$800 | Shut-offs, etc |
| Water heater | $600-$1,500 | Tank or tankless |
Electrical Materials
| Item | Typical Cost | Notes |
|---|---|---|
| Service panel & breakers | $400-$800 | 200A panel typical |
| Romex wire (by the roll) | $1,500-$3,000 | 14/2, 12/2, 10/2 |
| Boxes & fittings | $600-$1,200 | Outlets, switches |
| GFCI & AFCI breakers | $400-$800 | Code required |
HVAC Materials
| Item | Typical Cost | Notes |
|---|---|---|
| Furnace or heat pump | $2,000-$5,000 | Size dependent |
| Ductwork & fittings | $2,000-$4,000 | Supply & return |
| Registers & grilles | $400-$800 | Throughout house |
| Thermostat | $100-$400 | Smart vs basic |
Step-by-Step Process
Week 1-2: Plumbing Starts
Main stack installation:
- Install toilet flanges (measure carefully!)
- Run main drain stack
- Install branch drains
- Test fit all drain assemblies
Supply line installation:
- Run main water lines
- Branch to fixtures
- Install shutoff valves
- Pressure test system
Week 2-4: Electrical Rough-In
Service and panel:
- Install meter base
- Set service panel
- Run main feeders
- Install grounding system
Branch circuits:
- Run all circuit wiring
- Install boxes at correct heights
- Label all circuits clearly
- Separate dedicated circuits
Week 3-6: HVAC Installation
Equipment placement:
- Set furnace/air handler
- Position correctly for service access
- Connect to condensate drain
- Install vibration isolation
Ductwork installation:
- Install main trunk lines
- Branch to each room
- Seal all joints
- Insulate ducts in unconditioned spaces
Inspection Requirements
Plumbing Inspection
What inspector checks:
- Proper pipe sizing and slope
- Vent stack sizing and placement
- Trap locations and types
- Water test (holds pressure)
- Cleanout locations
How to prepare:
- Leave all pipes visible
- Cap all openings
- Pressure test before inspection
- Have drawings available
Electrical Inspection
What inspector checks:
- Service panel installation
- Circuit sizing and protection
- AFCI/GFCI compliance
- Box fill calculations
- Grounding and bonding
How to prepare:
- Label all circuits
- Have panel schedule ready
- Ensure all boxes are accessible
- Ground rods driven
HVAC Inspection
What inspector checks:
- Equipment sizing (may require Manual J)
- Duct sizing and layout
- Combustion air (if gas furnace)
- Condensate drain routing
- Clearances for equipment
How to prepare:
- Have equipment specs available
- Ensure proper clearances
- Condensate drain terminates properly
- Equipment secure and level
Common Mistakes
1. Poor Coordination
Problem: Trades working on top of each other, conflicts, delays Solution: Clear schedule, daily check-ins, resolve conflicts immediately
2. Insufficient Outlets/Circuits
Problem: Not enough outlets, circuits overloaded Solution: Add extra outlets now (cheap), dedicated circuits for high loads
3. Wrong Fixture Locations
Problem: Plumbing rough-in doesn't match actual fixture placement Solution: Have fixtures on-site before rough-in starts
4. Undersized HVAC
Problem: System can't keep up with heating/cooling demands Solution: Proper Manual J calculation, don't just guess
5. Leaky Ductwork
Problem: 20-40% of conditioned air lost to leaks Solution: Seal all duct joints with mastic (not just tape)
6. No Communication Between Trades
Problem: Plumber drills through electrical, HVAC blocks plumbing access Solution: Require trades to coordinate, mark conflicts early
7. Skipping Pressure Tests
Problem: Leaks discovered after drywall is up (expensive fix) Solution: Pressure test plumbing and HVAC before inspection
Quality Checkpoints
Before inspections:
Plumbing:
- [ ] All drains have proper slope (1/4" per foot minimum)
- [ ] Vent stacks sized correctly per code
- [ ] System holds pressure test (water or air)
- [ ] Cleanouts in accessible locations
- [ ] Toilet flanges at correct height (floor height + thickness)
Electrical:
- [ ] All circuits labeled in panel
- [ ] GFCI protection in required locations
- [ ] AFCI protection on required circuits
- [ ] Proper wire sizes for loads
- [ ] Boxes at correct heights (outlets 12", switches 48")
HVAC:
- [ ] Equipment sized correctly (Manual J calculation)
- [ ] Adequate return air (often 2x supply)
- [ ] All duct joints sealed with mastic
- [ ] Equipment has proper clearances
- [ ] Condensate drain has trap and terminates outside
Subcontractor Considerations
What to look for in subs:
All trades:
- Licensed and insured (verify!)
- References from recent jobs
- Understands code requirements
- Communicates well
- Willing to coordinate with other trades
Typical pricing:
Plumbing:
- Labor only: $8,000-$15,000
- Labor and materials: $15,000-$25,000
Electrical:
- Labor only: $8,000-$12,000
- Labor and materials: $12,000-$20,000
HVAC:
- Labor and materials: $15,000-$35,000
- (Equipment is large portion of cost)
Red flags:
- Won't provide license number
- Quotes significantly lower than others
- Doesn't ask about coordination
- Can't explain code requirements
- No insurance certificate
Timeline Tips
Critical path items:
- Rough-in inspections must pass before insulation
- All three trades must finish before moving forward
- Failed inspection = entire project delayed
How to stay on track:
- Schedule inspections 2-3 days in advance
- Don't schedule insulation until ALL rough-ins pass
- Have subs fix failures within 24 hours
- Keep other trades informed of delays
Budget Breakdown
Example for 2,000 sq ft home:
| Trade | Materials | Labor | Total |
|---|---|---|---|
| Plumbing | $3,000-$5,000 | $12,000-$20,000 | $15,000-$25,000 |
| Electrical | $3,000-$5,000 | $9,000-$15,000 | $12,000-$20,000 |
| HVAC | $8,000-$15,000 | $7,000-$20,000 | $15,000-$35,000 |
| **TOTAL** | **$42,000-$80,000** |
What Comes Next
After rough-ins pass inspection:
- Insulation (wait for ALL rough-ins to pass)
- Drywall installation
- HVAC trim out (registers, grilles)
- Electrical trim out (outlets, switches, fixtures)
- Plumbing trim out (fixtures, faucets)
Typical gap between phases: 1 week (immediately after rough-in inspections pass)
Related Resources
Need help coordinating multiple trades? Our subcontractor management guide covers scheduling, communication, and conflict resolution.