Rough-In Trades: Plumbing, Electrical, and HVAC
Overview
Three different trades — plumbing, electrical, and HVAC — work simultaneously, which requires careful coordination. How much you can do yourself depends heavily on the trade and your jurisdiction: many states let owner-builders do their own electrical and plumbing on a primary residence they don't intend to sell, while HVAC refrigerant work requires EPA 608 certification everywhere.
| Factor | Detail |
|---|---|
| Typical Duration | 6-10 weeks |
| DIY Difficulty | Hard (varies by trade and your jurisdiction) |
| Typical Cost | $40,000-$80,000 (2,000 sq ft house) |
| When to Hire | Depends on the trade and what your state allows |
| Required Inspections | Separate inspections for each trade |
When This Phase Happens
| Timing | What |
|---|---|
| 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?
What you can legally do yourself varies a lot by trade and by state, so don't assume any of these are off-limits until you've checked with your building department.
Electrical and Plumbing — Often DIY-able for Owner-Builders
Many states let owner-builders do their own electrical and plumbing work on their primary residence, provided you pull the permit, do the labor yourself, and aren't building the home to resell. Some jurisdictions require you to pass a basic competency test, and a few still mandate a licensed professional.
These rules vary widely. See our state-by-state owner-builder rules and the dedicated electrical rough-in and plumbing rough-in guides. Both trades are highly code-regulated, so study your adopted NEC/IPC edition and local amendments before you start.
HVAC — Refrigerant Work Requires Certification
You can often do ductwork and equipment setting yourself, but sizing (Manual J), charging, and commissioning are where DIYers most often go wrong — which is why most owner-builders hire HVAC out.
This applies everywhere in the U.S. — there's no owner-builder exemption for refrigerant work.
Electrical and plumbing are realistic DIY projects for a motivated owner-builder where your state allows it; the savings can be real. HVAC is the one most worth hiring out. Whatever you take on, the risks (code violations, failed inspections, safety issues, insurance problems) are real — so study the code, work methodically, and lean on professional help where you're unsure.
Save your easiest 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
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 issue | Detail |
|---|---|
| Vent stacks | Incorrectly sized or placed |
| Drain line pitch | Insufficient pitch (1/4" per foot for pipe under 3"; 1/8" per foot permitted for 3" and larger — verify your adopted IPC/IRC edition and local rules) |
| Pipe sizes | Wrong pipe sizes |
| Cleanouts | 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 requirement | Common issue |
|---|---|
| AFCI protection on most circuits (living areas) | Missing AFCI/GFCI protection |
| GFCI protection (bathrooms, kitchen, exterior, garage) | Insufficient circuits for modern loads |
| Dedicated 20A circuits for kitchen countertops | Boxes placed at wrong heights |
| Separate circuits for major appliances | 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 factor | Common issue |
|---|---|
| Proper load calculation (Manual J) | Oversized or undersized equipment |
| Adequate return air (often undersized) | Inadequate return air |
| Sealed ductwork (leaks waste energy) | Leaky ductwork |
| Correct equipment sizing | Poor duct layout |
Coordination Is Critical
Three trades compete for the same space. The electrician wants to run wire where the 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
| Timeframe | Work |
|---|---|
| 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
Each trade gets its own inspection. The tables below show what each inspector checks and how to prepare.
Plumbing Inspection
| What inspector checks | How to prepare |
|---|---|
| Proper pipe sizing and slope | Leave all pipes visible |
| Vent stack sizing and placement | Cap all openings |
| Trap locations and types | Pressure test before inspection |
| Water test (holds pressure) | Have drawings available |
| Cleanout locations | — |
Electrical Inspection
| What inspector checks | How to prepare |
|---|---|
| Service panel installation | Label all circuits |
| Circuit sizing and protection | Have panel schedule ready |
| AFCI/GFCI compliance | Ensure all boxes are accessible |
| Box fill calculations | Ground rods driven |
| Grounding and bonding | — |
HVAC Inspection
| What inspector checks | How to prepare |
|---|---|
| Equipment sizing (may require Manual J) | Have equipment specs available |
| Duct sizing and layout | Ensure proper clearances |
| Combustion air (if gas furnace) | Condensate drain terminates properly |
| Condensate drain routing | Equipment secure and level |
| Clearances for equipment | — |
Common Mistakes
| Mistake | Problem | Solution |
|---|---|---|
| 1. Poor Coordination | Trades working on top of each other, conflicts, delays | Clear schedule, daily check-ins, resolve conflicts immediately |
| 2. Insufficient Outlets/Circuits | Not enough outlets, circuits overloaded | Add extra outlets now (cheap), dedicated circuits for high loads |
| 3. Wrong Fixture Locations | Plumbing rough-in doesn't match actual fixture placement | Have fixtures on-site before rough-in starts |
| 4. Undersized HVAC | System can't keep up with heating/cooling demands | Proper Manual J calculation, don't just guess |
| 5. Leaky Ductwork | 20-40% of conditioned air lost to leaks | Seal all duct joints with mastic (not just tape) |
| 6. No Communication Between Trades | Plumber drills through electrical, HVAC blocks plumbing access | Require trades to coordinate, mark conflicts early |
| 7. Skipping Pressure Tests | Leaks discovered after drywall is up (expensive fix) | Pressure test plumbing and HVAC before inspection |
Quality Checkpoints
Work through these before inspections.
Plumbing:
- [ ] All drains have proper slope (1/4" per foot for pipe under 3"; 1/8" per foot for 3" and larger)
- [ ] Vent stacks sized correctly per code
- [ ] System holds pressure test (water or air)
- [ ] Cleanouts in accessible locations
- [ ] Toilet flanges at correct height (flange bottom rests on the finished floor surface)
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:
| Trade | Labor only | Labor and materials |
|---|---|---|
| Plumbing | $8,000-$15,000 | $15,000-$25,000 |
| Electrical | $8,000-$12,000 | $12,000-$20,000 |
| HVAC | (Equipment is large portion of cost) | $15,000-$35,000 |
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
- 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.