Nothing seems to get the short-shrift in the construction industry like interior fit-out scheduling. It’s natural for developers and general contractors to focus on core and shell, but that focus is too often at the expense of fit-out. A common assumption is that a contractor can breeze through fit-out, with the heavy lifting safely behind him, but this is seldom the case.

Core and shell contractors have a bit more latitude in how meticulous they need to be as compared to interior trades, which is why many only do one or the other. It can be said that many capable core and shell contractors take on interior work, as well, work they are not well suited to. Even when they parse the interior work out to specialty trades, they don’t always manage the work in a way that facilitates best practices.

This is often due to an underestimation of the complexities of coordinating finishes, and allowing proper duration and lag to perform adjoining work. Another way of saying the same thing is that ‘many contractors can’t get out of their own way’ or ‘they step on their own shoes. Indeed, much of the delay and budget shortfalls in the industry are driven by poor planning and decision making for interior fit-out scheduling. 

Competent schedulers will have enough field experience to know how to properly plan fit-out. As fit-out program increases in complexity, they aim to increase duration and lags. But contractors who sign up for overly aggressive schedules don’t always listen to their schedulers, or don’t have the luxury to.

“Although core and shell facilitates fit-out, discontinuity ensues when they are not closely coordinated. This is the rule rather than the exception.

Why don’t contractors don’t always allow sufficient duration in their interior fit-out scheduling to complete fit out? This may be a function of too much time devoted to getting out of the ground, or it may even be willful arrogance that drives the belief that fit-out can always and easily be accelerated to fit most any time frame – no matter how implausible. More often than not, the owner is driving an overly ambitious schedule that is unrealistic.

I’ve seen too many interior fit-out scheduling efforts that seemed needlessly accelerated: trades were stacked and resources pushed to extremes, even when there was ample float available to space out the work properly. As float evaporated, EOTs were rejected, as contractors were beholden to their contractual deadlines or baseline schedules. Since duration was already foreshortened, there was no more compression to be squeezed out.

Coordination Strategies 

Many  parameters that facilitate fit-out don’t lend themselves well to rushing through by mindlessly trade-stacking and overlapping activities. Diligent interior fit-out scheduling can minimize such disruptions:

• MEP roughing has a standard sequence of installation that must be observed in walls, and especially ceilings. Failure to observe this methodology is one of the most prevalent out of sequence operations a contractor can get disoriented with. The most common problem is trades blocking access to each other’s work in progress with their respective work-in-place, tradespeople, or both. Sadly, MEP coordination drawings are critical for design and fabrication, but do not provide sequence of installation unless someone deigns to refer to them as working drawings.
• Architectural woodwork, and wood doors and flooring need to acclimatize in a dry and heated area before being installed. Optimally, all wet work – plaster, stone setting, or floor leveling has cured before product reaches site. Otherwise, the product can be damaged or compromise its manufacturer warranty.
• Axes lines need to be planned such that they are not lost forever below floor leveling or plywood. If there is floor leveling, bridging between studs will need to be installed, as the leveling rises up the edge of the floor plate allowing for wallboard to be fastened.

The list goes on, and contractors have their own lessons learned which must be considered for interior fit-out scheduling. 

Interior fit-out scheduling sequence of operations

Interior work can commence before a space is waterproof or climatized. This includes MEP riser and branch work and rough framing. The caveat is that such work does not obstruct traffic, for example, a curtain wall system dropped from inside. However, if there is no control for storm water issuing from above, early fit out work can become inundated with water and dangerous to work around. Cast iron pipe risers and branches will quickly oxidize in a wet environment, creating more work. For this reason, contractors will plan to install temporary waterproofing every ten floors, or so, to limit infiltration.

From surveyor axes lines on the floor, lines will be transferred plomb, and a top plate will be fastened to the underside of the slab. Surveyor benchmarks will indicate the high point of the floor or slab, from which elevations will be referenced. This measurement is critical for top and bottom of duct and pipe, as well as alignments and clearances for door openings, electrical outlets, and plumbing valves.

Tin knockers will shoot anchoring for their hangers, and proceed to hang their duct using the top plate for reference, and benchmarks on the walls. This may be done as main sprinkler, and sanitary and vent lines are brought across from risers, and hung from Kindorf and clevers previously anchored in place.

Once duct is hung, carpenters frame down to floor plate and infill studs and door openings. . Optimally, ducts are pressure tested and insulated before electricians, fitters, and plumbers do their branch work, but this is seldom possible. Hopefully, trades have left room for insulators to access the duct.

As light-gauge framing reaches the perimeter, the firestop at edge-of-slab/curtain wall transition needs to be integrated. This can prove to be a time consuming stumbling block if it isn’t coordinated properly.

Testing and inspections for MEP are needed before walls and ceiling may be insulated, or receive blocking. Duct is supposed to be pressure tested but seldom is. Work in the wall is typically completed, and the walls closed well before the ceiling is ready to be closed.

Once walls and ceilings are closed they may receive compound coats. These must be applied in a dust free climatized space. Many designers specify Level IV and V finish criteria for their partitions –  a nuance that is categorically ignored by contractors at their own peril, if surfaces are not flat.

Other wet work, such as mud sets and stone tile should be installed while compound is being applied to the walls and ceilings, so to minimize overall wet-work duration. As stated above, wet-work prevents moisture sensitive goods from being delivered and acclimatized. However, some millwork – such as door jambs, may be needed as guidelines or taping-edges for partitions.

Once an interior is taped and sanded, it is vacuumed and made ready to receive finishes. Wood or other flooring material can be installed and protected, doors may be hung, and trims applied. Subsequently, prime and first coat of paint may be applied. It’s best practice not to endeavor to complete final top coat too soon, as it always seems to get scarred: better to apply the final top coat when most of the trades have demobilized.

Cabinetry and countertops are installed over the finished floor. Appliances and fixtures are connected. At this time, final painting may be planned. Optimally, switch plates and escutcheons do not need to be masked or cut-in, as their installation awaited final paint coat.

Lastly, window treatments, carpet, and other FFE are delivered and installed to the site, which is now free from debris and orphaned tradespeople hanging around performing endless punch-out work. Finally, a contractor shouldn’t advise substantial completion too early, as that will engender the never-ending punch-list phenomenon.

Interior fit-out scheduling is both an art and a science in which contractors must be fluent or possess working knowledge. It’s fairly elementary to separate those who do from those who don’t, as it is to assign them corresponding risk profiles.