CSI Division 03 cost codes, explained for concrete subs

If your cost codes don't map to Division 03 MasterFormat, your bids don't roll up cleanly into the GC's budget. Here's a plain-English map of every code and how to use them.

When a GC opens your bid, they're not reading line by line. They're rolling your numbers up into their own budget — and that budget is organized by CSI MasterFormat. If your cost codes don't map to Division 03 cleanly, you make their estimator's life harder, and you get fewer call-backs.

This isn't bureaucracy for its own sake. The contractors who win consistently send bids that drop cleanly into a GC's budget without translation.

03 10 00 — Concrete Forming and Accessories. Formwork, edge forms, bulkheads, formliners, embeds, anchor bolts. If it shapes the pour, it lives here. 03 20 00 — Concrete Reinforcing. Rebar (LB or TON), welded wire mesh (SF), post-tensioning. This is the steel inside the concrete. 03 30 00 — Cast-in-Place Concrete. The actual concrete material (CY) plus placement labor and finishing. Footings, walls, slabs, columns, beams. 03 40 00 — Precast Concrete. Plant-cast panels, double tees, precast stairs. Different supply chain, different code. 03 50 00 — Cast Decks and Underlayments. Lightweight insulating concrete on metal deck, gypsum underlayments. 03 60 00 — Grouting. Non-shrink grout under base plates, epoxy grout for equipment pads. 03 70 00 — Mass Concrete. Heat-controlled large pours — usually only on heavy civil and tall foundations. 03 80 00 — Concrete Cutting and Boring. Saw cutting, core drilling.

1. Lumping rebar into 03 30 00. Rebar is 03 20 00. Always. Even if you self-perform both, code them separately so the GC's budget rolls up clean. 2. Putting waterstop into 03 30 00. Waterstop is a forming accessory — 03 15 00. 3. Burying labor in material codes. When labor and material live on the same code, you can't analyze productivity. Bedrock's typed cost codes (material/labor/equipment/sub) keep them separate but rolled up to the right Division. 4. No code for embeds. Anchor bolts, weld plates, and inserts are 03 15 00 — and they're often the line item that causes RFIs at submittal time. 5. Inventing your own numbers. "Code 1003-A" means nothing to a GC's preconstruction team. Stick to the standard.

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