A client called me last spring, pretty upset, waving around a set of drawings and asking why the number he was holding was forty percent higher than the one I’d given him three months earlier. Same house. Same architect, even. I asked him one question before I answered anything else: is that the same set you had in March?<\/p>\n
It wasn’t. He’d been holding a schematic sketch back then. What he had in his hand now was a full construction document set, stamped, dimensioned, ready to permit. Nobody had explained to him that those two things aren’t really the same drawing at different stages of neatness. They’re closer to two different documents that happen to show the same building.<\/p>\n
That mix-up costs more goodwill than almost anything else in this business, and it’s completely avoidable once you know what you’re actually looking at.<\/p>\n
In this guide:<\/strong><\/p>\n Architects move through design in stages for good reason. Nobody wants to spend six weeks detailing a stair that gets deleted in the next round of client feedback. The problem is that every one of those stages produces a drawing set that looks, to somebody outside the industry, basically finished. Lines, dimensions, a north arrow, maybe even some shading. It reads as done.<\/p>\n It isn’t. And the estimate that comes off it shouldn’t read as done either.<\/p>\n I’ve watched contractors get burned both directions on this. Some quote off an SD sketch like it’s a CD set and eat the difference when scope firms up. Others get so cautious about early drawings that they price in so much contingency the client walks. Neither one is really a pricing problem. It’s a not-knowing-what-you’re-holding problem, and it’s worth ten minutes to fix permanently. If you haven’t already, it helps to pair this with how to read construction blueprints<\/a> first, since that guide covers the mechanics of a set once you know which one you’ve got.<\/p>\n Schematic design is the earliest stage that gets put on paper, and it’s meant to answer one question: does the general idea work. Room sizes are rough. Walls might not even be walls yet, more like zones where walls will probably go. Systems like HVAC and electrical usually aren’t shown at all, or they’re a single note that says “mechanical TBD.”<\/p>\n I tell people to think of SD as the stage where the architect is still arguing with the client about whether the kitchen should face the street. Nothing about the plumbing rough-in matters yet if the kitchen might move.<\/p>\n What you’ll typically find on an SD set:<\/p>\n What’s missing, almost always: structural sizing, MEP routing, finish schedules, door and window schedules, and anything resembling a dimension you’d want to cut lumber against.<\/p>\n An estimate off an SD set is a budget number, not a bid. Say that out loud to whoever’s asking for it. In writing, ideally.<\/p>\n DD is the stage where the vague zones from SD turn into actual rooms with actual dimensions, and the building starts committing to choices it can’t easily walk back from. Structural systems get a first pass. Major equipment gets located, even if it’s not fully sized. Materials start getting named instead of implied.<\/p>\n This is usually where a contractor gets pulled in for the first real budget conversation, and it’s also where the most expensive kind of assumption creeps in: treating a DD set like it’s locked. It isn’t. Finishes shift. Equipment gets value-engineered out. A wall that was masonry in DD sometimes comes back as metal stud in CD because somebody looked at the number and flinched.<\/p>\n What generally shows up by DD:<\/p>\n A DD-stage estimate is closer to real than SD, close enough that most owners start treating it as gospel. Worth reminding them it isn’t, the same way you’d flag a rough framing inspection isn’t the final walk-through.<\/p>\n By CD, the arguing is supposed to be over. This is the stamped, permit-ready set: full dimensions, structural calculations behind the framing plan, complete MEP drawings with actual routing, door and window schedules, finish schedules, and a full spec book sitting behind the drawings even if nobody in the field ever opens it.<\/p>\n This is the only stage where an estimate should carry real confidence, and even then, only if the set is current. Revision clouds still happen at CD. Value engineering still happens at CD, sometimes more aggressively than at DD, because now the owner’s looking at real bid numbers instead of a budget range and reacting to sticker shock.<\/p>\n What a complete CD set includes:<\/p>\n If someone hands you a set and calls it “final,” check the title block for a permit stamp before you believe them. A stamp is the difference between a set that’s actually final and one that’s final until the plan reviewer sends it back.<\/p>\n This is the part nobody explains well, and it’s the actual source of that phone call I mentioned at the top. The swing between SD and CD isn’t a sign that anyone did their job badly. It’s the design process working exactly as intended, and it typically moves in one direction: up. Rarely does more scope get discovered on the way down.<\/p>\n A rough industry rule of thumb, and it really is rough, not a promise: expect an SD-stage number to land somewhere in the neighborhood of plus or minus twenty to thirty percent off the eventual CD price. DD tightens that gap to something closer to plus or minus ten to fifteen percent. CD is where you’re finally pricing the actual building instead of a placeholder for one.<\/p>\n The reason it moves is almost always the same handful of things. Structural sizing comes in heavier once an engineer actually calculates loads instead of eyeballing them. MEP systems get fully routed and suddenly need more duct, more conduit, more labor hours than a single note implied. Finish selections upgrade as the client falls in love with samples. And code requirements that got waved off early, accessibility, fire rating, energy compliance, show up in full once someone’s actually stamping the set.<\/p>\n None of that means the early number was wrong. It means the early number was answering a different question.<\/p>\n\n
Why This Confusion Keeps Happening<\/h2>\n
Schematic Design (SD): The Napkin Sketch With Better Handwriting<\/h2>\n
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Design Development (DD): Where the Building Starts Making Decisions<\/h2>\n
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Construction Documents (CD): The Set You Actually Build From<\/h2>\n
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How the Numbers Move Between Stages<\/h2>\n
A Side-by-Side Comparison<\/h2>\n