Services Integration in CLT Buildings

In CLT construction, planning service integration early is crucial. Because CLT panels (used for floors, walls, and roofs) are solid and often left exposed as architectural features, traditional methods of hiding services in wall cavities or above suspended ceilings often do not apply. A combination of creative strategies is used to accommodate services as follows:

Dedicated Service Cavities or Furred-Out Linings

One common approach is to introduce a service cavity by adding a secondary framing or lining. For example, furring out a low wainscot wall or building a light-frame partition on the interior side of a CLT wall creates space to locate wires and pipes out of sight. In Australia, this is often done in bathrooms, kitchens, or corridors, where a thin stud wall or batten system is installed in front of the CLT, providing a gap for plumbing and electrical conduits while also allowing for insulation or acoustic buffering. An added benefit is improved acoustics, as the partition can disrupt sound transfer. In some cases, projects use double-stud walls or double CLT walls with a gap between, effectively forming a vertical shaft or cavity for services.

Exposed Services as Design Elements

Embracing exposed services is another strategy well-suited to mass timber architecture. Instead of hiding services elements, pipes, ducts, cable trays, and sprinklers can be left visible against the timber soffits and walls, often painted in a contrasting colour to create an industrial aesthetic. Many modern Australian CLT buildings adopt this look. For example, International House Sydney features black painted chilled beams, electrical conduit, and sprinkler pipes set neatly against the blonde timber ceilings, creating a crisp visual contrast. 

Figure 1: Exposed services as design elements

This approach not only celebrates the building’s structure but also simplifies maintenance and future retrofits because services are easily accessible. This can also provide a sustainability benefit through reduced waste when reconfiguring interiors). Exposed services require careful coordination to avoid visual clutter; in practice, designers group and align runs for a tidy appearance.

Pre-Planning Routes Within Panels

With CNC fabrication common to CLT suppliers, it’s possible to embed or conceal services within the CLT panels themselves. Manufacturers can use computer numerical controlled (CNC) milling to rout channels or bore holes in panels for pipes and conduits prior to delivery. Shallow grooves can be pre-cut in a wall panel’s interior face to lay electrical cabling, later covered by finishes. Small diameter holes can be drilled through floor or wall panels for plumbing or electrical penetrations, or even hardware as shown below.

Figure 2: CLT door with locking mechanisms and handles integrated. Seed House, Fitzpatrick + Partners.

This factory-cut approach maintains a clean finish with services hidden in the body of the timber, but it requires precise design coordination upfront, including detailed consideration of structural impacts, and does not allow for subsequent re-routing. Importantly, the structural cross-section reduced by any routing must be evaluated to ensure that the panel’s strength (and fire rating, if the cut is near a fire-exposed face) remains adequate.

Leveraging Floor and Ceiling Zones

For floor panels, designers can create dedicated zones above or below the CLT to run building services. One method that can be used is the addition of a raised access floor on top of CLT slabs. Above a CLT roof panel, a services zone can also accommodate HVAC plant or insulation layers to hide rooftop conduits. Alternatively, a drop ceiling or suspended soffit can be installed beneath the CLT floor to hide ducts and pipes. This can be done selectively, for example in corridors or bathrooms that have a lowered ceiling packed with services, whereas in main areas it is possible to leave the timber exposed. In composite assemblies, services can even be embedded in toppings, e.g. electrical conduits or hydronic heating tubes cast into a thin concrete screed above the CLT floor. 

Designated Shafts and Vertical Chases

Larger services and vertical risers, including plumbing stacks, ductwork for HVAC, or electrical trunks, are typically concentrated in planned shafts or service cores. In CLT buildings, these shafts can be constructed from CLT walls themselves or from fire-rated plasterboard systems, depending on the fire requirements. For example, a CLT building may include a central services core where CLT shaft walls enclose elevators, stairwells, and risers. CLT can provide the necessary fire-separation if designed to the required Fire Resistance Level (FRL), either by using sufficiently thick panels or the use of protective claddings. In other cases, especially for retrofit of services or additional lines, designers may run vertical pipes visibly in corners or along walls, with fire-rated wrap or boxing if necessary.

Note that some strategies above introduce concealed cavities, either within a dropped ceiling or a raised floor. Under building codes and fire regulations, concealed spaces in timber structures may require additional precautions. The Australian National Construction Code (NCC) typically mandates sprinkler protection in floor cavities or other measures to prevent unseen fire spread. (This parallels provisions in international codes: e.g., the US heavy timber code limits concealed spaces unless they are sprinklered or the timber is fully encapsulated with non-combustible material.) Early dialogue with fire engineers and building certifiers is essential to ensure any service integration strategy complies with fire safety provisions.

Integrating services into CLT requires careful planning of any penetrations or modifications to the timber panels. Routing refers to cutting channels or recesses in panels, usually completed in the factory with CNC machines, while drilling refers to making holes, which can be completed either in-factory or on-site. Both must be executed in a way that maintains the structural, fire, and acoustic integrity of the timber elements. 

Structural Guidelines for Openings

As every hole or notch in a CLT panel removes some wood, the structural outcome of its size and location should be accounted for. Although CLT design guides (including Australian codes that are currently in development) provide general principles, in practice engineers follow similar rules to those used for glue-laminated timber (glulam or GLT) beams and other timber elements. The main guidelines are to keep holes small and few, position them in low-stress zones, and prefer round holes over square cuts. For example, Europe’s timber code (EC5) suggests that holes be placed near the member’s neutral axis (mid-depth) rather than at areas of high bending stress, and away from supports where shear stress is high. A circular hole creates less stress concentration than a square or rectangular opening, so round penetrations are preferred, and are simpler to fabricate. In CLT floor slabs, this often means drilling openings in the middle third of the span and depth, and aligning them between major load paths (for example, through a low-moment region if the panel acts as a one-way slab). Small conduit holes (say up to 50–75 mm diameter) are usually acceptable in non-critical areas without reinforcement. Larger openings (e.g. for ducts or large pipes) typically require engineering checks and subsequent reinforcement around the opening. Reinforcement can be achieved by installing fully threaded self-tapping screws or glued-in rods around the hole to restore strength. These act like “stitches” that transfer forces around the cut-out zone. For example, if a 200 mm duct penetration is required through a CLT floor panel, the engineer will typically specify several screws angled around the opening to provide the tension and shear that would otherwise have gone through the missing wood. Many CLT suppliers publish allowable opening sizes or details for common service penetrations; when in doubt, it’s best to consult the manufacturer or a timber structural engineer early in the design phase.

Routing Channels in Panels

Routing a shallow channel into a CLT panel (for example, to recess an electrical conduit or pipe) reduces the panel’s effective thickness locally. If the routed side is not the structural tension face under bending, the effect on strength may be minor; however, if it is necessary to route the underside of a floor panel (the tension face when loaded), this could result in the bending capacity being reduced. As a general rule, avoid deep or wide chases that significantly diminish section properties. Any route deeper than, say, one lamella of the CLT should be reviewed by an engineer. Additionally, it’s important to consider the fire implication: CLT’s fire resistance comes from charring of its surface. If a channel is routed into a face that is exposed to fire, the protective char layer has effectively been thinned. In some cases, if routed grooves are on a fire-exposed side, it may be prudent to treat them with intumescent paint, or apply fire-rated coverings, to maintain the element’s Fire Resistance Level (FRL).

Moisture and Durability Considerations

Timber is sensitive to moisture, so it’s important that service installations are detailed to prevent water ingress. All plumbing lines within or near CLT should be carefully sealed: a small leak in a concealed pipe can cause wood rot over time. It’s good practice to use sleeves and sealants where pipes penetrate panels, and ensure any wet-area plumbing has appropriate waterproofing. For cold water or chilled HVAC pipes, it’s important to insulate against condensation to ensure that no moisture condenses on the wood. Similarly, avoid routing services that produce significant heat without separation: hot water pipes or light fixtures should either be kept a small distance off the timber or be outfitted with heat-resistant spacers, because continuous heat can dry or char the wood over time (though normal plumbing temperatures are usually safe).

Mechanical and Electrical Equipment Compatibility

It’s important to consider how equipment will be fixed to timber and any vibrations or noise that could be transferred. Heavy services, including air handling units or pipes full of water, require secure mounting, which is typically achieved using coach screws or specialty timber anchors into the CLT. The structural engineer should confirm that the panel can carry these point loads, potentially adding blocking or thicker areas where necessary (some CLT suppliers can locally thicken or reinforce regions that will receive heavy connections). Vibration isolation is another important factor: timber floors are lighter than concrete, so they are likely to transmit mechanical vibrations more readily. Using resilient mounts for pumps/fans and flexible connections for piping can mitigate against vibration travel. Electrical compatibility is generally straightforward, but it is important to follow Australian wiring rules (AS/NZS 3000) regarding cables in insulated enclosures. If cables run through a drilled hole in wood, derating might be required, as is the case in a stud wall. Also, ensure metal conduits or pipes penetrating through CLT are properly fire-stopped (as metal can conduct heat through an assembly if not insulated at the penetration).

Summary

One of CLT’s advantages is that, unlike concrete, it is possible to cut or drill it relatively easily on-site if adjustments are required with regular woodworking tools. However, every penetration must be considered: it should be planned with structural input, coordinated in size/location, and executed with proper sealing for acoustic, moisture, and fire performance. By observing the guidelines above and consulting relevant standards (for example, AS 1720.1 for timber engineering principles and AS 4072.1 for service penetration fire stopping), designers can integrate services without compromising the integrity of the timber structure.

Penetrations are defined as any openings cut through CLT panels for services, from small holes for pipes to larger openings for ducts or cable trays. Proper detailing of these penetrations is critical to maintain fire safety, acoustics, and structural performance. Meanwhile, risers refer to vertical runs of services between floors (often accommodated in shafts or aligned openings), and service zones are designated spaces in the building layout for routing multiple services in parallel (either horizontally or vertically). This section describes how to detail these elements correctly.

Fire-Safe Penetrations

When a service penetrates a fire-rated timber wall or floor, the opening must be sealed to prevent fire and smoke from passing through. Australian Standard AS 1530.4 sets out the testing requirements for fire-resistant assemblies, and AS 4072.1 provides guidance for installing penetration seals. In practice, this means using proprietary fire-stopping systems that have been tested and approved for use in CLT or timber assemblies. Fortunately, as mass timber construction has grown, so have the number of solutions available. Manufacturers like Trafalgar, Hilti, and others offer fire collars, wraps, sealant systems, and fire-rated sleeves specifically tested on CLT walls and floors. For example, Trafalgar’s documentation lists various tested passive fire penetration systems to maintain the FRL of service penetrations through CLT wall systems. These include intumescent pipe collars that swell and seal a plastic pipe hole in a timber wall during a fire, flexible fire batts or sealant for cable bundles, and fire-rated wraps for ducts. Many of these systems achieve up to 2 hours fire resistance (Integrity and Insulation) when installed as per the test configuration. The essential design requirement is to coordinate penetration sizing with available firestop systems, i.e. design your pipe openings to match a fire collar size that’s been tested for timber. Each penetration should be detailed on drawings with a reference to an approved fire-stopping method. Additionally, it’s important to maintain adequate edge distances: a penetration too close to the edge of a CLT panel or another penetration might invalidate a fire test, so follow the manufacturer’s guidelines (which often require a certain minimum timber thickness around the opening).

Acoustic Sealing

Service penetrations can also be weak points in acoustic separation between rooms or floors. Sound can travel through small gaps around a pipe (flanking noise). Thus, after fire-stopping is installed, it’s important to ensure the opening is also acoustically sealed: usually the fire seal (such as an intumescent sealant or mineral wool) doubles as an acoustic seal if properly installed. For critical cases, for example a plumbing riser in a residential building, additional acoustic wrap or insulation around the pipe within the cavity can help dampen sound. In Australian apartments, a waste pipe might be enclosed in a small shaft with insulation and multiple layers of fire-rated plasterboard, to meet both FRL and acoustic requirements of the NCC. Detailing should specify that any gaps are fully treated and that materials used have the necessary acoustic attenuation (many fire-rated sealants are also tested for sound reduction).

Grouping and Lining of Risers

A riser typically extends vertically through successive floor panels. The most straightforward approach is to design a vertical shaft that aligns through the building, into which pipes or ducts can be installed. In a CLT structure, this can necessitate the creation of a stacked opening in each floor panel, essentially a straight chase through the CLT floors, often boxed out with a steel sleeve or formed by CNC-cut holes that line up when panels are erected. These openings must be large enough to allow for the service plus insulation/fire-stopping around it. An alternative is to route the riser within a timber or plasterboard shaft that runs alongside the CLT structural elements (for example, a service riser could run adjacent to an elevator core or at the corner of a room). Multiservice risers (i.e.several pipes/cables together) should be approached with caution: mixing too many services can complicate fire-stopping, and electrical and wet services are usually separated for safety. It’s often preferable to provide multiple smaller penetrations grouped by service type (e.g. one for plumbing, one for electrical) than one very large opening. Each floor penetration in a riser requires a fire seal where it passes through the floor. There are tested systems where a fire-resistant board or seal is installed at each floor level inside a CLT shaft to compartmentalise it. In Australian practice, it’s necessary to consider NCC provisions for fire isolation of vertical shafts. Garbage chutes, stairwells, and duct shafts are required to have specific FRLs. A CLT wall can form the shaft wall if it meets the requisite FRLs, often achieved by adding gypsum board layers or using thicker panels calculated with char rates.

Service Zones and Coordination

The concept of service zones is predicated on the reservation of certain areas for routing Mechanical, Electrical, Plumbing (MEP) without clashing with structure. Horizontally, this could mean a defined ceiling zone (as discussed earlier) or a raised floor plenum where all services run so that the rest of the space is clear. Vertically, it could mean clustering pipes and ducts in a few aligned vertical zones rather than spread through every bay. In mass timber buildings, the early design should identify where these zones will be located. For example, an engineer could designate a 300 mm strip along a corridor ceiling as the main duct route and avoid running beams there, or provide a “utility band” in an apartment layout where plumbing from all wet areas aligns floor-to-floor. Multidisciplinary coordination will typically map out these zones in the BIM model. A general requirement is to keep as many services as possible in shared pathways, thereby reducing the number of penetrations needed in the structural panels. One possible strategy is to use prefabricated service modules: for example, a bathroom pod or a vertical utility module that contains all necessary pipes, which can be dropped into a pre-framed shaft in the timber structure. This confines complex pipework to a controlled zone and simplifies on-site connections.

Finally, it’s important to document the penetration details in models, on plans and in coordination drawings. By clearly indicating where holes will be located and of what size, the CLT supplier can incorporate them into fabrication to exact dimensions, for a neat fit on site and thereby avoiding ad-hoc core drilling. The detailing phase should involve discussions between the architect, engineer, and services consultants to agree on each penetration. This level of upfront detail is often higher for CLT projects, but it typically results in improved construction efficiency.

A fundamental decision in mass timber construction is how much of the service routing to pre-fabricate (pre-cut or cast-in) versus leaving to on-site installation. CLT panels are made to order, so there is an opportunity to precision-cut all service penetrations in the factory. However, doing so requires a high level of coordination before manufacturing begins. Let’s compare the approaches and see how projects balance them:

Pre-Routing and Factory Cut-Outs

The preferred option in a fully integrated project is to have the CLT manufacturer cut all openings, chases, and penetrations as part of the CNC machining process. This yields extremely accurate and clean openings: holes are in the exact specified locations, at the correct size, with no field drilling errors. Pre-cut panels also have a better aesthetic finish, with no ragged holes or patching required on site. From a program perspective, having penetrations pre-cut can speed up on-site works, since trades can immediately run their services through the provided holes without delay. For example, on a six-story CLT office project in Seattle, early coordination enabled the factory to include every HVAC sleeve and conduit penetration in the panels, resulting in a 20% faster rough-in time for services. Pre-routing also means less noisy, dusty work on site (important since one goal of mass timber is to achieve quieter, cleaner construction).

However, pre-cutting requires that the design of all services be complete and clash-free at the time of panel fabrication, often months before CLT assembly and many months ahead of services installation. A high level of design coordination is therefore essential. If a penetration was overlooked or was misaligned, contractors can face the tricky task of cutting a new hole through finished timber elements on site which can delay work and would likely require engineering approval. Consequently, design teams often build in a safety margin: for example, cutting a few extra spare conduits or slightly oversized shafts to allow for future needs or minor adjustments. Another tactic is prefabricated MEP modules: assembling pipes or ducts in a rack that matches the CNC-cut openings, to guarantee fit. 

On-Site Drilling and Adaptation

Inevitably, some service coordination may be required on site, especially in renovation or when final equipment selections happen late. CLT allows a degree of on-site alteration, and contractors can use conventional carpentry tools (drills, hole saws, routers) to cut timber panels. There’s no rebar to avoid, and no silica dust as with concrete coring. For example, if an extra data conduit is needed, an electrician can surface-run it or drill a small hole through a CLT wall with a spade bit and then fire-caulk it – tasks that are far simpler than drilling through concrete. That said, unplanned field penetrations should be minimised. Each on-site cut potentially voids the manufacturer’s warranty or the tested fire system if not appropriately accounted for. This type of on-site remediation also risks hitting embedded connections (if near a panel joint) or causing structural issues if a large hole is placed in the wrong spot. Therefore, any hole added in the field should be assessed by the engineer for approval. In construction of Australia’s mid-rise timber buildings, strict protocols are often set: the locations of any core drilled holes must be signed off, and often the CLT supplier will advise on how to reinforce or seal them. Contractors might use special drilling templates or guides to ensure a straight, clean hole through thick panels.

Balancing the Two Approaches

A pragmatic approach is to use “as much prefabrication as possible, but plan for contingency.” This requires a significant amount of coordination in the early stages of a project, using BIM to locate major penetrations, sleeves, and hangers, and pre-cutting those in the panels. Many teams include a MEP coordination phase before panel fabrication, where the model from each discipline is merged and every clash resolved. Given CLT’s limited adjustability, involving the services engineers at this stage is vital. As WoodWorks (USA) notes, drilling or coring after fabrication is highly discouraged and penetrations should be pre-planned and coordinated with structural and fire consultants. Once on site, a few minor adjustments may be needed (perhaps a missed wiring hole or an enlargement of an opening due to a spec change). By anticipating this, the design team can build in a margin for error. For example, it might be possible to leave a couple of floor joist bays intentionally free for future ducts or include an empty conduit run in the design for extra cables. Some projects even coordinate spare penetrations: a closed-up opening that can be utilised later if required.

Another consideration is the construction tolerance and actual placement. Pre-cut penetrations assume that the CLT panels and the connected services will all fit perfectly. Unfortunately, there may occasionally be some slight deviations on-site. For example, a pre-cut hole in a CLT floor for a pipe might be offset by a few centimeters if the pipe routing in the slab below shifted. To mitigate this, contractors can use layout techniques like surveying the as-built panel positions and slightly oversising openings for flexibility. If a hole is not used or is bigger than needed, it must be properly fire sealed or filled, which can be done with fire-rated mortar or timber infill as appropriate.

In summary, pre-routing maximises efficiency and precision, aligning with the overall prefabrication philosophy of CLT construction, while on-site adjustments provide some level of flexibility where necessary. The best outcomes occur when the team invests in early coordination, leveraging BIM and early contractor involvement where possible, so that virtually all services are accounted for in the factory drawings. Australian architects and builders have quickly learned that “measure twice, cut once” is particularly appropriate: or perhaps “model many times, CNC cut once” in the CLT context. By front-loading the coordination work, it is possible to avoid expensive rework later and fully capitalise on CLT’s undoubted off-site manufacturing potential.

Building a successful CLT project with smoothly integrated services is truly a multidisciplinary undertaking. It requires breaking down the traditional barriers between architects, structural engineers, services engineers, fire consultants, and contractors. Coordination is not a linear process, but a collaborative, iterative one, enabled by digital tools and early contractor involvement. Below are key coordination practices and recommendations observed in contemporary Australian timber projects:

Early Design Collaboration

From the schematic design phase, it is important to bring all disciplines together to discuss the implications of a mass timber structure on service layout. Timber systems have different constraints than concrete or steel. By ensuring the mechanical, electrical, plumbing (MEP) designers and the structural engineer are brainstorming together early, it is possible to align the structural grid and panel layout with the needs of HVAC and pipe distribution. In practice, this might involve the structural engineer adjusting beam placements to create a clear route for a duct, or the architect allocating a thicker floor buildup to allow acoustic insulation plus a conduit zone. Early collaboration helps identify and resolve conflicts when it’s still easy to amend the design.

Use of BIM and Digital Coordination

Mass timber projects in Australia nearly always use Building Information Modeling (BIM) as a coordination tool. The 3D BIM model isn’t optional, it’s essential for clash detection and precise documentation. Teams should establish a shared model (or well-coordinated linked models) between architecture, structure, and MEP. Regular coordination meetings where everyone reviews the combined model help identify potential problems or conflicts. With CLT, millimeter-level accuracy is achievable, and the model should reflect that, teams often model even the screw connections and exact conduit diameters to avoid any surprises. During coordination, particular attention should be paid to intersections of disciplines: for example, how do fire walls and floor panels interface with ducts and pipes? Are there any concealed spaces inadvertently created? Are all penetrations addressed with a specified detail? The digital model is used to answer these questions, and the output is a coordinated penetration schedule and set of shop drawings that the CLT fabricator and subcontractors will follow.

Defined Zones and “Rules of Engagement”

An effective practice is to identify MEP zone allocations and rules early in the design phase. For example, the design team might agree that “all piping on plan Level 3 will run within 200 mm of Gridline B between Grids 1 and 5” or “no conduits to cross the exposed ceiling in the lobby, they will route via the adjacent room”. By clearly defining such zones, each discipline knows where they can and cannot put their components, simplifying the layout. Similarly, define load limits on the timber for the services engineers, such as the maximum allowed weight of services per meter that can hang off a CLT panel (the structural engineer can provide this). The integrated MEP zones approach keeps systems organised and minimises on-site improvisation. In tall mass timber buildings, vertical shafts are one such zone, often clustered at the core. For horizontal distribution, some projects use a ceiling zone within a band near corridors. Whatever the solution, it is important to document these zones in the drawings and enforce them during coordination reviews. It essentially becomes a game of 3D Tetris to pack ducts, pipes, and cable trays into a confined area, but once solved in the model, it greatly de-risks construction.

Prefabrication and Modular Services

The philosophy of prefabrication in CLT can extend to the services themselves. Australian contractors increasingly explore prefabricated service modules that can be rapidly installed on site, aligning with the quick installation of CLT structure. For example, a restroom “cassette” may come with all plumbing pre-fitted, connecting via a few points to the building’s mains. On a larger scale, multi-trade racks where electrical conduit, plumbing, and sometimes ductwork are mounted on a frame which can be built off-site and lifted into place, especially in repetitive corridors or plant rooms. These assemblies need to be designed to fit the CLT openings and support conditions precisely, which is linked to meticulous coordination. The main advantages are significant time savings on site and higher quality (since the assemblies are built in a controlled environment). Coordinating modular MEP elements in the design phase also forces the team to resolve spatial issues early in the design phase.

Fire and Life Safety Coordination

Integrating services in a timber building requires close involvement of the fire engineer or code consultant. All penetrations and service enclosures must meet stipulated performance requirements. The fire engineer will advise on where fire-resistant enclosures are needed. For example, they might require that certain plastic pipes be run within non-combustible shafts, or that an intumescent paint be applied to exposed CLT surfaces within a return air plenum. A practical coordination step is to create a penetration register listing each opening, its fire rating requirement, and the proposed fire-stopping method, and have it reviewed by the fire consultant and building certifier. Services designers must also plan for fire sprinkler integration from the start – mass timber buildings in Australia generally require sprinklers throughout (often as a trade-off for other concessions). Sprinkler mains and drops should be coordinated such that sprinkler heads can be installed without unsightly surface conduit; often this is done by recessing sprinkler pipework slightly or grouping it with other services runs. In terms of life safety, also consider smoke detection in areas with exposed timber (fire engineers will need to ensure that sensor placement accounts for the different thermal properties of wood structures) and ensure emergency electrical systems (like fire alarm cables) are appropriately protected when routed through timber.

Acoustic and Vibration Teamwork

Acoustic consultants play a key role in service integration for sensitive projects where noise is a particular concern (e.g. hotels, apartments, offices). The structural-acoustic-service triad will need to work out floor build-ups (for impact sound) and details like pipe isolation. The acoustic engineer might specify, say, a 50 mm insulation layer under a raised floor; the mechanical engineer is then aware that it is possible to run flat ducts in that space but must not compress the insulation. Similarly, if the acoustic design calls for no rigid contact between a waste pipe and the timber structure (to prevent structure-borne noise), it may be necessary to use rubber grommets in the penetration sleeve. By resolving these issues in coordination meetings, the design team can avoid scenarios where, for example, a contractor might otherwise rigidly clamp a pipe to a CLT beam that was meant to be vibration isolated.

Documentation and Construction Phase Coordination

Once designs are finalised and construction commences, maintaining coordination is still imperative. It can be beneficial to conduct a services coordination workshop on site just before CLT installation begins, reviewing the panel drawings with the relevant tradespeople. This ensures everyone on site is aware of the installation sequence (e.g. which panels have to be installed before certain pipes can be connected, etc.). As panels are erected, it is important to survey and confirm that critical penetration locations are correct. A technique that has been used in some projects is to require the services contractor to be on site when the first panels with major openings are installed. In this way they can immediately verify that, for example, the prefabricated duct will align with the curb provided. Any minor adjustments can then be communicated quickly (e.g. “we need to slightly ovalise this particular hole to accommodate a coupling”). During construction, if unforeseen changes occur, perhaps an electrical change order adds a conduit, the team should reconvene to assess how to integrate it without compromising the timber (it might be routed externally or in a manner that avoids new cuts to structure).

Summary

In essence, early and regular communication is key. The integrated design and delivery process for CLT and services is perhaps best summarised by the mantra: “proactive planning, not reactive fixing.” By engaging all disciplines early, leveraging precise modeling tools, and establishing clear zones and responsibilities, Australian project teams have been able to regularly deliver timber buildings where services coexist elegantly with structure. The result should be both technically sound (meeting structural, fire, acoustic demands) and architecturally pleasing. As mass timber construction becomes more mainstream, these coordination practices are increasingly becoming standard professional conduct, ensuring that the vision of a clean, sustainable timber space is matched by the reality of functional, well-serviced buildings.