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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So assembly is a very important aspect of construction. There are 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, if you don't have to, you don't want to take off all the studs, measure out all the studs, wood studs, metal studs, the width, the spacing of them, the height, the drywall, the track at the base, the taping finish, everything associated with that partition.
Whereas you can actually have a unit cost for that assembly, which might be $2.75 a square foot, instead of pricing out 20 different items. Now keep in mind that the 20 different items are priced out at some point, and they roll up into that unit cost of $2.75. So that's where the unit costs do come from. But the whole idea is that you do not need to go to the level of detail necessary for that partition type, if you already know what all is included in an interior partition that's got stud spacing at 16 inches on center and is 10 feet high.
So assemblies are extremely helpful because they speed up the entire process. If you price them out individually, it'll take you a lot longer and you have to calculate every component individually. Whereas when you have an assembly unit cost of $70 per square foot, all you have to do is come up with the total square footage.
Now there might be exceptions. If you have an interior wall that is $70 a square foot, well it has a variable of that price is only good up to, let's just say, 10 feet high. If it's above 10 feet high, up to, let's just say, 18 feet high, it's another price, and so on.
The reason being is that the labor costs go up every time you go up another increment of 8 or 10 feet. And it requires scaffolding, safety protection, what have you. Use assemblies whenever you can.
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But make sure that you first verify and validate what that unit cost is. Have a good understanding of what's inside that assembly. Know what it's composed of.
And therefore, if you use an assembly that's slightly different for a different wall type, as an example, you could price out the assembly at $70 a square foot, and then maybe have another add-on for an extra layer of drywall.
