vertical-construction

name	vertical-construction
description	Domain knowledge for the construction vertical (contractors, field crews) so architect and pm don't spec construction products naively. Covers the vocabulary (bid vs estimate, takeoff, retainage, change order, AIA G702/G703, lien waiver, draw schedule), the non-obvious money rules that incumbents like Procore price out of reach for small contractors, what a naive build gets wrong (no assemblies, ignored retainage, ungated sub payments), and the entities that must be modelled. Applied by architect when writing ARCH-{slug}.md and by pm when writing PLAN-{slug}.md for any of the four construction products (bid-builder, project-mgmt, subcontractor-portal, field-docs).
when_to_use	Apply when: - architect writes ARCH-{slug}.md for a construction product (bid-builder, project-mgmt, subcontractor-portal, field-docs) - pm decomposes a construction feature into PLAN-{slug}.md tasks - design-advisor wireframes a construction screen (estimate, billing, sub payment, daily log) - any spec touches money flow (billing, payment, retainage) in the construction vertical Do NOT apply to non-construction verticals — the money rules (retainage, lien waivers, AIA pay apps) are construction-specific and will mislead elsewhere.
effort	low
allowed-tools	Read, Write, Grep, Glob
paths	["docs/architecture/**","docs/plans/**","docs/design/**"]

Vertical: construction — don't spec it naive

Construction has its own money physics. A spec that treats a contractor's billing like a SaaS invoice will ship something no contractor can use, because the cash flow it ignores (retainage held back, draws against a schedule of values, subs gated on lien waivers) is the thing the contractor is trying to manage. This skill gives architect and pm the vocabulary and the non-obvious rules so the four construction products are specced from domain reality, not intuition.

The four products and their incumbents:

Product	Archetype	Wedge against
bid-builder	marketplace-lite	Excel (small contractors estimate in spreadsheets)
project-mgmt	crud	Buildertrend, Contractor Foreman
subcontractor-portal	marketplace-lite	Procore, manual COI/payment tracking
field-docs	crud	Procore field tools, paper daily reports

Incumbents: Procore (enterprise, ~$375+/mo minimum — too expensive and heavy for small contractors; do not fight it head-on), Buildertrend (residential-focused), Contractor Foreman, Autodesk Construction Cloud (enterprise). The opening is small contractors priced and complexity'd out of these.

Domain vocabulary (use these terms exactly in specs)

• Estimate — internal cost calculation (what the job will cost the contractor). Bid — the priced number submitted to win the job (estimate + markup). Proposal — the customer-facing document wrapping the bid with scope, terms, exclusions. Estimate → bid → proposal are three artifacts, not synonyms.
• Takeoff (quantity takeoff) — counting/measuring quantities from plans (sq ft of drywall, linear ft of pipe) that feed the estimate. Garbage takeoff = garbage bid.
• Unit cost + assembly — an estimate is built from line items priced per unit (e.g. $/sq ft). An assembly bundles several unit-cost items into one (a "door assembly" = door + frame + hardware + labor). Real estimating is assemblies, not freehand numbers.
• Markup vs margin — markup is added on top of cost (cost × 1.20). Margin is the cut of the bid price (price − cost) / price. 20% markup ≠ 20% margin. Mixing them mis-prices the job. Spec which one a field means.
• — a contracted change to scope/price after the bid is signed. Untracked COs are where margin leaks and disputes start.