Equipment & Cost Overrides

Manual override system for equipment quantities, unit costs, and cost summary line items — deployed 2026-02-23

Why Overrides?

Six retail/branch banking building blocks have no standard equipment mappings in the database. Craig manually adjusts these quantities in his Excel spreadsheet. The override system replicates this flexibility in the web app.

Equipment Overrides

Change auto-calculated equipment quantities and unit costs, or add entirely new equipment items not in the reference data.

Cost Overrides

Override any individual cell in the 15-row cost summary table (Equipment, Installation, CAPEX, OPEX, BAU columns).

Override Flow

Calculate — Auto-calculation runs the standard chain (building blocks, network design, derived items, security)

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Review Tech Breakdown — View auto-calculated equipment with quantities and unit costs

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Edit Equipment — Click any Qty or Unit Cost cell to edit inline. Add new items via form at bottom. Overridden cells turn orange

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Edit Cost Summary — Click any cell in the cost summary table to override. Also highlighted orange

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Save & Recalculate — Persists all overrides to DB, recalculates with overrides applied, refreshes view

Calculation Chain Integration

Equipment overrides slot into the existing calculation chain at step 7, after all auto-calculation but before totaling. Cost overrides apply after the 15-row summary is built.

Step	Operation	Type
1-2	Space aggregation + data points	Auto
3-6	Tech breakdown, network design, derived items, security	Auto
7	Equipment overrides applied — replace qty/cost, insert new items	Override
8	Category totals (qty x regional unit prices)	Auto
9	Cost summary (15-row table with formulas)	Auto
10	Cost overrides applied — replace individual cells	Override

API Endpoints

Method	Endpoint	Purpose
GET	/api/projects/:id/equipment-overrides	Load saved equipment overrides
PUT	/api/projects/:id/equipment-overrides	Save equipment overrides (delete + insert)
GET	/api/projects/:id/cost-overrides	Load saved cost overrides
PUT	/api/projects/:id/cost-overrides	Save cost overrides (delete + insert)

All PUT endpoints use a delete-then-insert pattern within a transaction.

Data Model

project_equipment_overrides

Column	Type
project_id	FK → projects
item_name	VARCHAR(200)
category	VARCHAR(100)
quantity_override	NUMERIC(10,2)
unit_cost_override	DECIMAL(12,2)
is_addition	BOOLEAN

Unique on (project_id, item_name)

project_cost_overrides

Column	Type
project_id	FK → projects
cost_line_item_id	FK → cost_line_items
equipment_override	DECIMAL(12,2)
installation_override	DECIMAL(12,2)
capex_override	DECIMAL(12,2)
opex_override	DECIMAL(12,2)
bau_override	DECIMAL(12,2)

Frontend Components

EditableTechBreakdown.tsx

Inline-editable equipment table replacing the read-only tech breakdown. Click any Qty or Unit Cost cell to edit. Orange highlighting for overrides. "Add Equipment Item" form at bottom with category dropdown. Per-row X button to revert overrides.

EditableCostSummaryTable

Inline in ProjectView.tsx. Click any cell in the 15-row cost summary to edit. Orange highlighting for overridden cells. Per-cell clear button to revert. Auto-formatted as currency on blur.

Visual indicator: All overridden values are highlighted with an orange background so users can instantly see what has been manually changed vs auto-calculated.

Key Files

File	Purpose
backend/src/services/calculator.ts	Override application in calculation chain (Step 7)
backend/src/routes/projects.ts	4 override CRUD endpoints
backend/src/routes/calculations.ts	Loads overrides from DB, passes to calculator
frontend/src/components/EditableTechBreakdown.tsx	Editable equipment table component
frontend/src/pages/ProjectView.tsx	Editable cost summary + save/recalculate wiring
scripts/init-db.sql	project_equipment_overrides table definition

📖 Detailed override documentation | Calculation engine | API & Data Model | Back to WIT PropTech