---
name: cost-report
description: Roll the assessed claim, the variation register and the commitments into a single budget versus committed versus forecast position, with the movement since last month explained. Use after claim-check and variation-log have run.
---

# Cost Report

## What it does
Produces the financial section of the monthly report: where the budget stands, what is committed, what is forecast at completion, and what moved this month and why.

## When to use
- Monthly, once the claim is assessed and the variation register is current.
- Before any client conversation about budget.

## Instructions
1. Ask for: the approved budget, the assessed valuation from claim-check, the variation register from variation-log, all consultant and supply commitments, and last month's cost report.
2. Build the position by element: budget, committed, expended to date, forecast at completion, variance.
3. Show the movement since last month for every element that changed, and give the reason for each in one sentence.
4. Keep the contingency as its own visible line. Show what was drawn this month and what remains.
5. Separate the approved position from the exposure position, carried through from variation-log.
6. Use only figures present in the source documents. Where a figure is missing, write "not provided" and do not estimate it.
7. Forecast cashflow for the remaining periods if the programme allows it.

## Output format
- Cost summary by element: budget / committed / expended / forecast / variance
- Movement since last month, with a reason per line
- Contingency: opening, drawn this month, remaining
- Exposure: claimed-but-unapproved variations and pending claims
- Forecast final cost, stated as a range where inputs are uncertain
- Assumptions and exclusions

## The one mistake to avoid
Letting the model fill a gap with a plausible number. Every figure must be traceable to a source document. "Not provided" is a valid and much safer output than an invented total.

## Where the real tools are
Open-source equivalents worth forking:
- https://github.com/datadrivenconstruction/DDC_Skills_for_AI_Agents_in_Construction/tree/main/4_DDC_Curated/Financial-Management/budget-variance-analyzer
- https://github.com/datadrivenconstruction/DDC_Skills_for_AI_Agents_in_Construction/tree/main/4_DDC_Curated/Financial-Management/cashflow-forecaster