Builders who do not know what each unit really costs are flying blind. The materials that go into a shed add up quickly: every stick of lumber, every tube of caulk, and every sheet of sheathing has a price, and the difference between a profitable job and a loss often comes down to a quarter sheet of plywood. Accurate cost tracking starts with understanding how direct and indirect construction project costs behave differently as volume changes.
Manufacturers that track costs seriously build a breakdown for every style, size, and model they produce. One manufacturer in North Carolina offers 120 different sizes and styles, from an 8 by 8 storage unit to a 14 by 40 building, and accounts for everything down to the nails and screws in the roof. Another shop keeps a bill of materials for every model, with quantity and cost listed for each component. That level of detail turns pricing from a guess into a calculation.
Three cost questions frame the whole exercise: what does the material cost, what does the labor cost, and what does it cost to run the plant while the work happens? Answer all three per model and pricing becomes arithmetic. Skip one and the numbers drift, which is why the most detailed trackers account for every part of every building, right down to the fasteners.
Why Every Model Needs Its Own Cost Breakdown
A 10 by 12 shed and a 14 by 40 garage use completely different ratios of lumber, sheathing, and labor. Blending them into one average cost hides which models carry the business and which ones quietly lose money. A model-level breakdown lets a builder set percentage targets for materials, manufacturing, delivery, and overhead, then measure every build against them.
The discipline scales with the company. A one-person shop can run the numbers in a spreadsheet, while a larger operation moves to software built for the job. Builders who grow past a handful of models typically adopt formal job cost systems and percentage-of-completion accounting to keep the same level of detail as the business gets more complex.
Model-level detail also exposes the models that should not be sold at all. A 12 by 24 building with heavy custom trim may consume 55 percent of its retail price in materials while a plain 12 by 24 runs at 46 percent. Without separate breakdowns, the custom version looks profitable in the averages and quietly drags the margin down. Builders who catch that pattern either raise the price on the custom build or simplify the trim package.
Building a Bill of Materials for Every Size
A bill of materials, or BOM, lists every component that goes into a building, organized by the order the work happens. One manufacturer in South Carolina organizes materials by build process: floor, wall framing, siding, roof framing, roof covering, doors, paint, and miscellaneous items, with quantity and cost recorded for each. The list is spreadsheet-based because of limitations in the company’s enterprise resource planning system, a common workaround for small manufacturers.
- Floor: joists, sheathing, fasteners, and skids
- Wall framing: studs, plates, headers, and hardware
- Siding: panels, trim, and fasteners
- Roof framing and covering: rafters, sheathing, shingles or metal, and flashing
- Doors and windows: units, hardware, and caulk
- Paint and finish: primer, topcoat, and touch-up supplies
- Miscellaneous: caulk tubes, nails, and consumables
The BOM answers pointed questions: how many sheets of floor sheathing does a 10 by 20 building need? How many coils of nails go into a 10 by 16 shed? How many tubes of caulk does a 10 by 12 building use? A builder who cannot answer these questions is like a shepherd who cannot count sheep before nightfall: the numbers only get harder to find later.
- List every material by build process, in the order it is installed.
- Record the quantity per unit, down to quarter-piece counts for lumber.
- Add the unit cost and extend it to a line total.
- Add manufacturing overhead, sales commission, shop labor, and installation, averaged across the buildings produced each year.
- Review the BOM whenever a material price changes.
Waste belongs in the BOM too. Cut lumber produces offcuts, sheathing produces edge drops, and caulk tubes never empty completely. Tracking waste per model, rather than guessing at a flat percentage, shows which designs cut efficiently and which ones leave money in the scrap bin. It also catches theft and damage, because a model whose material consumption climbs while its build count stays flat has a problem somewhere between the lumber rack and the loading dock.
Breaking Down Cost of Goods Sold
Cost of goods sold, or COGS, covers everything spent to produce a building. Manufacturers typically factor in materials, labor including doors, trusses, and finish work, and plant overhead. Plant overhead includes facility maintenance, repairs, electricity, plant management, rent or lease, waste removal, supplies, and insurance. This split mirrors the standard division of direct and indirect project costs used across construction accounting.
| COGS component | What it includes | Example target |
|---|---|---|
| Materials | Lumber, sheathing, fasteners, paint, doors | Under 50 percent of retail price |
| Shop labor | Cutting, assembly, doors and trusses, finish work | Under 12 percent of retail price |
| Plant overhead | Rent, utilities, maintenance, insurance, waste removal | Tracked separately, held flat per unit |
| Sales and delivery | Commissions, fuel, crew time | Under 10 percent each of retail price |
Plant Overhead Versus Office Overhead
Keeping plant overhead separate from office overhead follows generally accepted accounting principles. Plant overhead belongs to production: the building, its utilities, and the management time spent on the floor. Office overhead is the true overhead account for administration, sales support, and management above the plant level. Mixing the two makes it impossible to see what a building actually costs to produce, and it makes the percentage targets meaningless.
Labor gets tracked the same way. Shops with commission-based sales and build teams find it easy to budget labor as a percentage of revenue, because the expense moves with the work. Shop labor covers cutting, assembly, doors and trusses, and finish work, and it needs its own line so a slow week in the shop does not get buried in a general labor account.
Setting Percentage Targets for Every Cost Category
Percentage targets give a quick health check for any model. One manufacturer in North Carolina works to keep material costs under 50 percent of the retail sales price, shop labor under 12 percent, and both sales expenses and delivery under 10 percent each. The targets get evaluated every quarter, and more often when material prices are volatile. Accounting rules also change the categories themselves; new lease accounting standards now reshape contractor balance sheets, so the tracking system has to keep pace with the rules.
Why Material Cost Targets Matter Most
Materials are the biggest single line in a shed’s cost, which is why the 50 percent ceiling matters. When lumber prices spike, a model that sat at 48 percent materials can jump to 55 percent overnight, wiping out the profit margin unless the retail price moves with it.
Adjusting Targets When Prices Spike
Volatile markets call for reviews more often than once a quarter. A builder who checks material percentages monthly can raise prices or swap components before a bad month turns into a bad quarter. The spreadsheet behind every model makes those checks a five-minute job.
Percentage targets also guide pricing decisions. If a model’s materials climb from 47 percent to 52 percent of retail, the builder can raise the price, switch to a cheaper component, or accept a thinner margin to keep volume. The target makes the trade-off visible, and the quarterly review turns it into a decision instead of an accident.
Delivery: Inside the Cost or Outside It?
Manufacturers disagree on where delivery belongs. One camp includes delivery in the building cost, arguing that if you are not factoring in delivery, you do not know where the company stands financially. The other camp keeps delivery out of shed costs because delivery teams work on commission with a budget based on percent, which keeps the expense predictable without muddying the production number. Either approach works, as long as delivery gets measured somewhere. Delivery exposure deserves the same attention as builders risk insurance for the structures themselves: both are risks that can wipe out a thin margin if ignored.
Delivery costs break into fuel, crew time, mileage, and permits, plus the occasional soft-ground call that needs a second truck. A percent-based delivery budget works when the delivery area stays stable; dealers who expand their radius have to recheck the percentage, because a 90-mile delivery costs far more than a 10-mile one even when the building price is identical.
Reviewing Costs on a Schedule
A cost system only pays off when someone reviews it on a regular schedule. Quarterly reviews catch drift in material prices, labor efficiency, and overhead before it becomes a pricing problem. The review compares actual percentages against targets, model by model, and triggers action when a line breaks its band.
Cost surprises hide in the details, and site conditions hold some of the biggest ones; steep site foundation costs show how quickly an estimate can miss when the ground fights back. Builders who track every model, review every quarter, and adjust every target keep those surprises small and their prices honest.