Stud spacing is one of those specification decisions that disappears behind the wall linings and is never visible to the tenant, yet it quietly decides how the partition performs for the life of the fitout. The two standard intervals in commercial office work are 400 mm and 600 mm centres. The 600 mm option is cheaper, faster and lighter. The 400 mm option is stiffer, more acoustically cooperative, and more forgiving of services penetrations. Either can be the right answer. What makes the decision wrong is specifying one by default without asking what the wall is actually being asked to do.
In most commercial offices, the bulk of the plasterboard partition scope is general-purpose wall between meeting rooms, offices and circulation. That scope is usually best served by 600 mm centres, and the cost saving across a full floor is meaningful. The situations where 400 mm centres earn their premium are narrower and predictable: high-traffic zones, acoustically demanding rooms, walls carrying wall-mounted fixtures, and walls where future modifications are likely. Knowing which is which is the specification call that matters.
What Stud Spacing Actually Controls
A plasterboard partition is a frame of vertical metal studs with horizontal top and bottom tracks, lined on each face with sheets of plasterboard. The studs carry no structural load beyond the wall itself; their job is to hold the lining flat, hold it vertical, and give the fixings something to bite into. Stud spacing is the distance between adjacent studs, measured centre to centre.
Closer spacing does three things. It stiffens the wall against lateral load, reducing drumminess when the wall is knocked or leaned against. It reduces the span of unsupported plasterboard between fixings, which changes how the wall resonates and how tolerant it is of impact. And it provides more points to fix wall-mounted items (shelving, whiteboards, screens, joinery) without hunting for a stud or using cavity anchors.
Wider spacing saves steel, screws and labour across the partition run. On a floor with a hundred linear metres of plasterboard partition, moving from 600 mm to 400 mm centres adds roughly 30 per cent more studs and a similar proportion of installation time. The cost difference on a mid-size fitout is measurable; whether it is worth paying depends on where the partition is and what the tenant will do with it.
600 MM Centres: Where The Standard Spec Holds Up
For internal partitions in general office areas, 600 mm centres match the standard plasterboard sheet size cleanly. A 1200 mm wide sheet lands on three studs, the middle one hitting the sheet’s centre and the outer two catching the edges. The wall sits flat, the fixings are predictable, and the system works as designed.
Most commercial office partitions do not face conditions that justify tighter spacing. A meeting-room wall that carries a small whiteboard, a painted finish, and the occasional chair leaning against it will perform perfectly well at 600 mm centres. The wall feels solid when it is correctly installed, the acoustic rating meets the specification, and there is no visible or tactile indication to the occupants that the spacing is anything other than standard.
Where 600 mm sometimes gets chosen for the wrong reasons is on walls that will clearly be asked to do more than that. A meeting-room wall that will carry a large wall-mounted screen, a bank of shelving, or a video wall is not a standard-specification wall. Specifying 600 mm there because it is the default is not a cost saving; it is a problem being deferred to whoever has to retrofit a backing plate later.
400mm Stud Centres For Acoustic Office Partitions
The clearest case for 400 mm centres is a wall that has to feel stiffer than standard. Corridors with high traffic, walls between busy meeting rooms and open-plan zones, walls in training rooms where participants lean against them, and any wall that will be used as a casual leaning surface all benefit from closer spacing. The wall resists knock damage better, the lining does not dent as readily, and the general sense of solidity is noticeably higher.
The second case is acoustic. A double-stud partition in a rated meeting room relies on the two stud lines being independent, and on each line being stiff enough not to transmit vibration to its lining. The choice between single-stud and double-stud construction is a separate decision from the spacing one, but the two interact: at 600 mm centres, a single-stud rated partition can still meet the rating, but it is more sensitive to sheet weight, sealant quality and installation discipline. At 400 mm, the same wall meets the rating with more margin and is less affected by small variations in build quality. For rooms where the rating is being genuinely relied on (audio rooms, executive offices discussing confidential matters, training rooms with mixed cohorts), the extra margin is worth the cost.
The third case is walls that will carry wall-mounted equipment. Screens over 55 inches, cantilevered shelving, heavy joinery fixings, and whiteboards over 1200 mm wide all benefit from 400 mm centres. The installer can fix the bracket directly to studs at sensible spacings rather than introducing plywood backing plates retroactively, and the resulting fixing is stronger and more serviceable.
The fourth case is walls that will be modified during the lease. A wall with closer stud spacing is more forgiving of adding a door, cutting in a glazed panel, or introducing a services penetration in the middle of the run. The installer has more intact studs to work with after the modification and is less likely to need to rebuild the whole partition line.
Acoustic Performance: What The Spacing Really Changes
Acoustic ratings for plasterboard partitions are typically quoted in lab conditions with ideal installation. The real-world performance usually lands a few points below the lab number because of site variation. Stud spacing is one of the factors that decides how much of that lab performance survives translation to the finished wall.
At 600 mm centres, the plasterboard panels between studs have more span. They vibrate more freely when sound waves hit them, which is how sound transmits through a partition. Adding mass to the sheets (heavier board, double-layer construction, or resilient mounting) compensates, and most standard-rated office walls achieve their target rating at 600 mm with the right sheet specification.
At 400 mm centres, the sheets have less span. They vibrate less and transmit less sound through the cavity. The rating improvement over an identical 600 mm wall is typically in the order of one to two decibels, which is modest in isolation but meaningful when stacked with other small improvements, including double-layer plasterboard construction for acoustic control, denser insulation and heavier sheet specification. On rated walls where the target rating is at the upper end of what the system can deliver, closer spacing is often what converts “theoretically compliant” into “comfortably compliant”.
The other acoustic consideration is flanking transmission through the wall itself. Closer spacing reduces the sheet area that can act as a large vibrating surface, which softens the characteristic drumminess of a lightweight stud wall. In an executive office or a boardroom where the wall is noticeable at close range, that softer response is a genuine quality difference.
Stud Spacing Decisions For Specific Room Types
A useful way to think about the decision is by room function rather than by wall. The walls around a general meeting room, standard circulation and non-acoustic private offices are comfortable at 600 mm. The walls around a boardroom, a confidential meeting room, or a rated training room usually deserve 400 mm. The walls carrying heavy wall-mounted equipment, regardless of what the room is, should be at 400 mm with timber or steel noggings at fixture height.
Reception walls are a special case. They are high-traffic, often carry signage, and are usually the first thing visitors see when they arrive. 400 mm centres with a higher-grade finish level is the straightforward specification call.
Comms room and plant room walls have their own logic. They carry cable trays, brackets and services penetrations, they often have to be fire-rated, and the common mistakes in comms and plant-space partitions almost all trace back to tight design conditions and thin stud frames. 400 mm centres with appropriate stud gauge is almost always the right answer, and attempting to save there is usually a false economy.
Kitchen and break-out area walls often get specified at 600 mm by default and then get loaded with wall-mounted cabinetry, pinboards and equipment that they were not framed for. Thinking through what the wall will carry at the design stage, rather than at the joinery stage, often leads to a small but useful move to 400 mm in those specific zones.
The Specification Conversation With The Installer
The practical path to the right stud spacing on a given fitout is a walk-through of the partition scope with the installer before the linings are quoted. Most installers default to 600 mm unless told otherwise; most tenants assume the rated walls automatically come at tighter spacing, and sometimes they do not. A twenty-minute conversation that identifies which walls are rated, which walls will carry fixtures, and which walls the tenant plans to modify during the lease is usually enough to get the spec right.
The cost conversation is straightforward. Adding tighter spacing on the walls that need it does not typically double the cost of the partition scope; it adds a noticeable but manageable increment, usually in the single-digit percentage range for most commercial fitouts. Compared with the cost of retrofitting backing plates, re-doing acoustic work, or rebuilding a damaged wall, the upfront premium is usually the smaller number.
The worst outcome is a fitout that specifies 600 mm across the board because nobody asked the question, and then discovers within a year that the boardroom wall resonates, the reception wall feels flimsy, or the screens in the training room cannot be mounted where they were meant to be. The second-worst outcome is a fitout that specifies 400 mm across the board because somebody wanted to avoid the conversation, and pays for stiffness it does not need on walls where no one will ever notice.
If you are specifying plasterboard partitions for a Sydney commercial office and want to get the stud spacing decisions right before the linings are priced, we can walk the scope with you and tighten the spec where it earns its cost. Our plasterboard partitions service covers standalone partition works as well as full fitouts, and the specification walk is the most useful place to start.
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