When you’re building an ADU, every choice matters. You’re not just trying to pass inspections, you’re trying to build something that feels solid, safe, and permanent. Drywall is one of those details that seems small, but it affects fire rating, sound control, durability, and the final look of your space.
One of the most common questions we get is:
Should I use 1/2″ drywall or 5/8″ drywall for my ADU?
Technically, 1/2″ drywall is slightly cheaper. But in real-world ADU projects, that difference is usually so small that it doesn’t justify giving up the benefits of 5/8″.
What’s the Real Price Difference Between 1/2″ and 5/8″ Drywall?
From a good supplier, the difference is usually about $1–$2 per sheet.
Most ADUs use well under 300 sheets, which means:
- The total material difference is often just a few hundred dollars
- Labor stays the same
- The performance benefits far outweigh the cost difference
Unless your project is:
- Over 500 sheets
- Or requires carrying drywall up multiple flights of stairs
You typically won’t notice a meaningful price change by choosing 5/8″.
Why 5/8″ Drywall Is Better for ADU Builds
1. Better Fire Rating
5/8″ drywall has a higher fire resistance rating than 1/2″.
This matters in ADUs where:
- Fire separation is critical
- Structures are close together
- Safety requirements are stricter
It adds protection without complicating the build.
2. Stronger, More Solid Walls
5/8″ drywall is denser and stiffer.
That means:
- Walls feel more solid
- Less flexing
- Better long-term durability
It gives your ADU a “real home” feel instead of a temporary structure feel.
3. Helps Hide Framing Imperfections
Framing is never perfectly straight.
5/8″ drywall absorbs minor inconsistencies better, which means:
- Cleaner lines
- Less shadowing
- Smoother final appearance
Especially important in small ADU spaces where lighting hits walls harder.
4. Improved Sound Control
ADUs are all about privacy.
Thicker drywall reduces sound transfer between:
- Rooms
- Units
- Main house and ADU
It makes a noticeable difference in daily comfort.
Do You Pay More for Labor With 5/8″ Drywall?
No.
We don’t charge extra labor for installing 5/8″ drywall versus 1/2″.
Hanging drywall is hanging drywall. The process is the same.
The only times labor might change slightly:
- Large commercial-size projects
- Multiple flights of stairs
- Extremely limited access
For standard residential ADUs, labor stays the same.
Why We Recommend 5/8″ Drywall for Most ADUs
Because it:
- Improves fire safety
- Improves sound control
- Improves finish quality
- Makes walls feel stronger
- Costs very little more
It’s one of the few upgrades that improves multiple parts of the build at once.
This is why we don’t see 5/8″ drywall as “overkill.”
We see it as doing things right the first time.
Drywall Finish Matters Just as Much
ADUs usually have:
- Strong lighting
- Smaller rooms
- Tighter spaces
That means drywall finishing quality matters more.
Most ADUs work best with:
- Standard smooth (imperfect smooth)
- Level 4 finish
- Or light hand texture depending on style
5/8″ drywall gives us a better base to work from, which means:
- Cleaner corners
- Better ceiling lines
- A finish that looks intentional
Drywall for ADUs Is About the Full System
Drywall isn’t just sheets on studs. It’s part of a system that includes:
- Insulation
- Fire separation
- Sound control
- Finish quality
- Long-term durability
We often bundle insulation and drywall together for ADU projects because:
- It simplifies scheduling
- Keeps costs tighter
- Ensures the wall system performs correctly
The Short Answer
If you’re building an ADU:
- 5/8″ drywall should be your default choice
- The price difference is minimal
- Labor doesn’t increase
- Fire safety improves
- Sound control improves
- Finish quality improves
Unless you’re working on an unusually massive project or extreme access conditions, 5/8″ drywall is simply the smarter option.
It’s a small decision that pays off for the life of the building.
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