Discover the efficiencies of using assembly units in construction, saving time by grouping components into a singular unit cost rather than calculating each element individually. Learn the variations in cost with assembly units and the importance of understanding the composition of each unit.
Key Insights
- Assembly units in construction are comprised of all the elements necessary for a specific unit of work. For example, an interior partition might include all the studs, drywall, and finishing work. Rather than costing each element individually, they can be bundled into a single unit cost, accelerating the pricing process.
- While unit costs simplify the pricing process, they have limitations. For instance, a unit cost might be valid only up to a certain height, with costs increasing for each increment above that due to additional labor and safety provisions needed, such as scaffolding.
- It's crucial to validate and understand the components of an assembly unit before using it. If a slightly different assembly is used, the base unit cost can be applied, with additional costs added for any extra components, like an extra layer of drywall.
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Assembly is a very important aspect of construction. There is a collection of items required to complete a particular unit of work. For example, if you have an interior partition, you don’t necessarily want to take off all the studs if you don’t have to. You don’t want to measure all the studs—wood studs, metal studs—their width, spacing, height, the drywall, the track at the base, the taping and finishing, and everything else associated with that partition.
Instead, you can use a unit cost for that assembly, which might be $2.75 per square foot, instead of pricing out 20 different items. Now keep in mind that those 20 different items are priced out at some point, which are rolled up into that unit cost of $2.75. So that's where the unit costs come from. The main idea is that you do not need to go into the level of detail necessary for that partition type if you already know everything that is included in an interior partition that has stud spacing of 16 inches on center and is 10 feet high.
So assemblies are extremely helpful because they speed up the entire process. Pricing them out individually will take much longer and require you to calculate every component individually. Whereas when you have an assembly unit cost of $70 per square foot, all you have to do is calculate the total square footage.
Now, there might be exceptions. If you have an interior wall that is $70 per square foot, the price may only be valid up to, let’s say, 10 feet high. If it’s above 10 feet—up to, let’s say, 18 feet—it may fall under a different price tier, and so forth.
The reason is that labor costs go up every time you increase height by another increment of 8 or 10 feet. It also requires scaffolding, safety protection, and other requirements. Use assemblies whenever appropriate.
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But make sure that you first verify and validate what that unit cost is. Have a good understanding of what is included in that assembly. Know what it is composed of.
Therefore, if you use an assembly that is slightly different for a different wall type, for example, you could price out the assembly at $70 per square foot and potentially include an add-on for an extra layer of drywall.
