Partition Wall Thickness in mm: A Complete Guide: 1 Minute to Understand the Ideal Partition Wall Thickness for Your Space

Partition wall thickness in mm is one crucial detail that often makes the difference between a cramped, inefficient room and a functional, stylish space. Even when square footage is identical, the smart choice of partition wall thickness directly impacts how open, practical, and well-insulated a home feels. As someone deeply versed in unlocking every inch of small apartments and homes, I can say with confidence: underestimating partition wall thickness is among the most common (and costly) design mistakes homeowners make.

So, what’s the standard? And how thin is too thin? Let’s dive into the key considerations—blending style, utility, and compliance with current building standards—to ensure you get the perfect partition wall thickness for your next project.

Bottom line up front: For most residential interiors, the optimal partition wall thickness typically falls between 75 mm and 150 mm (about 3–6 inches), determined by material choice, spatial constraints, sound/privacy needs, and fixture requirements. Choosing the right thickness means maximizing usable space without sacrificing quality or comfort.

Understanding Standard Partition Wall Thickness in mm

Partition walls are non-load-bearing interior solutions crafted to define rooms, create privacy, and improve space utility. Unlike structural walls, they are not meant to support floors or roof loads. The industry standard for partition wall thickness in mm is as follows:

1. Gypsum board/drywall: 75–100 mm
2. Lightweight block (AAC, concrete): 100–120 mm
3. Brick: 100–150 mm
4. Glass partitions: 10–20 mm for panels, mounted in structural frames

Material selection drives the wall’s thickness, but so do acoustic, fire-rating, and fixture-mounting needs. 75 mm gypsum partitions are especially popular for small homes or apartments, as they create meaningful room divisions without encroaching excessively on the floor area—an approach validated by the National Association of Home Builders (NAHB).

However, more thickness isn’t always better. Extra centimeters boost performance (like sound attenuation), but can shrink livable space—an important trade-off in compact homes.

Key Factors Determining Partition Wall Thickness

When selecting optimal partition wall thickness in mm, consider:

1. Material Type: Drywall, glass, AAC block, or brick each have baseline thickness requirements for performance and code compliance (refer to American Institute of Architects [AIA] guidelines).
2. Acoustic Performance: Thicker or double-skin partitions, insulated cavities, or acoustic panels are essential where privacy or noise reduction is crucial (bedrooms, studies).
3. Fixture Load: Walls supporting cabinets, shelves, or TVs must be sturdy enough — requiring thicker stud frameworks or denser block/brick walls.
4. Fire Rating & Code Compliance: Consult local codes and refer to guidelines like HUD’s Minimum Design Standards for required fire resistance in multifamily or rental properties.
5. Space Optimization: In dense urban apartments, every millimeter matters. Strategic use of thinner walls—without compromising stability or code—can free up significant room.

Clients often regret partitions that are either too thick (wasting precious space) or too thin (insufficient privacy and flimsiness). Experience shows the sweet spot is usually between 75 mm and 120 mm, tailored to the job.

Pitfalls & Solutions: Optimizing for Small Spaces

For studios and apartments, consider 75 mm reinforced drywall systems for regular partitions, and supplement with 10–12 mm tempered glass for visual openness. Using a hybrid wall—half-glass, half-drywall—often delivers privacy, light flow, and a perception of space. Remember, a thin wall shouldn’t mean poor acoustics: request integrated insulation batts for even 75 mm systems.

Example: In a 600 sq ft New York apartment, switching from 120 mm block walls to 75 mm insulated drywall liberated over 2% more usable area (JCHS, Harvard University Homes Study 2023). That can mean an extra closet, home office nook, or more generous walkways—major upgrades in small footprint homes.

Material Comparisons: Which Partition Wall Thickness is Best?

Material Typical Thickness (mm) Best For Notes Gypsum Board/Drywall 75–100 General-purpose, fast installation Can be soundproofed, low embodied carbon (per USGBC) Glass 10–20 (pane) + frame Light transmission, visual openness Requires reinforced framing for safety/strength AAC Block 100–120 Stability, moderate sound insulation Good for kitchens/bathrooms Brick 100–150 High sound/fire protection Best for heavy-duty needs, but eats into space Choose the thinnest, code-compliant solution that delivers necessary privacy, sound, and fire protection. Never compromise safety for space: always confirm compliance with LEED and ADA standards if required.

Expert Tips: Getting Partition Wall Thickness Exactly Right

1. Factor in finishes: Paint, plaster, tile, and paneling typically add 8–12 mm per side—plan accordingly to avoid tight squeezes for furniture or openings.
2. Visualize with planning tools: Use a digital floor planner such as Coohom or SketchUp to test wall placements and thicknesses before construction—you might spot unexpected circulation bottlenecks or clearance issues.
3. Don’t cut corners on important walls: For media rooms, bedrooms, and bathrooms, prioritize thicker, well-insulated walls for peace and privacy.
4. Consult your local code or a professional: Certain fire and sound regulations may mandate minimum wall thickness—especially in multifamily/apartment buildings.

Pro tip: Always measure twice before finalizing partitions—one extra centimeter can mean the difference between a functional closet and a frustration!

FAQ

Q: What is the standard partition wall thickness in mm for US homes?

A: For most interior drywall partitions, standard thickness is 75–100 mm. Masonry partitions typically range up to 150 mm, depending on code and application.

Q: Is a thicker partition wall always better for sound or fire resistance?

A: Thicker generally improves sound/fire performance, but material composition and insulation are equally crucial. Soundproof drywall or acoustic batts in a 75 mm cavity can match a 100 mm hollow wall’s performance (per NAHB).

Q: Are glass partitions structurally safe at 10–12 mm thickness?

A: Yes—when using tempered or laminated glass and proper framing, panels between 10–12 mm (about 3/8–1/2 inch) are widely installed for office and residential interiors. Always comply with safety glazing codes.

Q: How do I balance room size with privacy when selecting partition wall thickness?

A: Assess privacy/sound needs, required fire rating, and spacings for fixtures/furniture. Use the thinnest compliant material for non-critical partitions; opt for enhanced sound insulation only where needed to save space.

Q: Does wall thickness impact ADA or local building code compliance?

A: Absolutely. Adequate clearances for accessibility, as well as minimum fire/sound ratings, may dictate your wall thickness. Always verify with your local authority or contractor architect.

Want to see how different partition wall thicknesses look and feel in your space before you build? Try Coohom’s Floor Planner for a real-time visual preview. You’re just a few clicks from smarter, more spacious living.