Preliminary Cost Estimate Report

Use this skill when a quantity surveyor, cost manager, owner's representative, or project estimator needs to produce a preliminary (Class D / Schematic Design level) construction cost estimate for a new building, renovation, or civil works project. Covers elemental cost breakdown, location and contingency factors, exclusions and assumptions log, and a cost manager review block.

Converts project brief information into a DRAFT Class D (Schematic Design / Order-of-Magnitude) construction cost estimate report with an elemental cost breakdown, location and market-condition adjustments, tiered contingencies, and a clearly documented assumptions and exclusions list. Produces a report for the cost manager or QS to verify before presenting to the owner or design team.

Flow

Phase 1 — Project Intake

Ask one question at a time. Wait for each answer before proceeding.

1. Project identification: project name, client/owner name, location (city and country/region), and intended use date for the estimate.
2. Project type: select the primary category:
   • New construction vs. renovation/addition (state percentage of existing building affected if renovation)
   • Building type: office, retail, residential multi-family, residential single-family, industrial/warehouse, healthcare, education, hospitality, mixed-use, civil/infrastructure, other (specify)
3. Gross floor area: total GFA in m² or ft² (specify unit). For multi-building projects, list each building separately.
4. Construction type: structural system (wood frame / light gauge steel / structural steel / cast-in-place concrete / precast concrete / masonry / other) and number of above-grade and below-grade storeys.
5. Occupancy and code basis: intended occupancy classification and applicable building code jurisdiction (e.g., IBC 2024, NBCC 2020, AS 1170, Eurocode).
6. Scope inclusions: which of the following are in scope? (Confirm each) — site preparation and earthworks, foundations, structural frame, exterior envelope, roofing, interior fitout, mechanical (HVAC), electrical, plumbing, fire protection, elevators, site services (utilities), landscaping and site works, demolition.
7. Scope exclusions and owner-supplied items: list items the client will supply directly or are excluded from the GC's scope (e.g., FF&E, owner-procured equipment, telecom, security, art).
8. Project quality level: economy / standard / mid-range / high-end / premium (affects unit-rate selection).
9. Available reference data: has the user provided a design brief, area schedule, concept drawings, or comparable project costs? If yes, ask the user to share them now.

Confirm the scope summary with the user before proceeding.

Phase 2 — Location and Market Adjustment

Apply location cost indices to base rates:

1. Identify the cost index region for the project location (use Rider Levett Bucknall, Turner & Townsend, or RSMeans regional indices as the reference framework — state the reference used).
2. Apply a location multiplier relative to the base index city (e.g., 1.00 = national average; note that actual index values must be verified by the cost manager).
3. Note the current market-conditions factor: hot market (escalation > 5% p.a.) / stable / soft. Flag if the estimate is being used more than 6 months from the estimate date — cost escalation should be reapplied.

Phase 3 — Elemental Cost Build-Up

Produce a table of cost elements. For each element, state: Element | Description of Scope Included | Unit Rate ($/m² GFA or $/ft² GFA) | Quantity | Total Cost | Notes/Assumptions.

Standard elements (include all; mark N/A if confirmed out of scope):

#	Element
1	Demolition and site preparation
2	Substructure (excavation and foundations)
3	Superstructure (frame and upper floors)
4	Roof construction
5	External walls and cladding
6	Windows, doors, and glazing
7	Internal partitions and doors
8	Floor finishes
9	Ceiling finishes
10	Wall finishes
11	Fittings, fixtures, and equipment (built-in only)
12	Plumbing and sanitary
13	HVAC and mechanical ventilation
14	Electrical and lighting
15	Fire protection (sprinkler and detection)
16	Vertical transportation (elevators, escalators)
17	Hydraulics and specialty piping
18	Communications and security rough-in
19	External works and landscaping
20	Site services and utilities connections

After each element, note the assumed unit rate source: comparable project data / published cost guide / regional benchmark / cost manager adjustment.

Phase 4 — Contingency and Risk Loading

Apply three tiers of contingency:

Tier	Purpose	Typical Range	Applied Rate
Design contingency	Incomplete design definition at schematic stage	15–25% of construction cost	State applied %
Construction contingency	Unforeseen conditions and minor scope changes	5–10% of construction cost	State applied %
Escalation contingency	Cost movement between estimate date and tender/award	Depends on program	State applied % and basis period

State the reasoning for each applied rate. If the user has provided a project schedule, compute escalation to the midpoint of construction.

Phase 5 — Cost Summary and Report Assembly

Produce the DRAFT report:

DRAFT — FOR COST MANAGER REVIEW
PRELIMINARY COST ESTIMATE REPORT

Project:         [PROJECT NAME]
Client:          [CLIENT NAME]
Location:        [CITY, COUNTRY]
Building Type:   [TYPE]
GFA:             [X] m² / ft²
Estimate Class:  Class D — Schematic Design / Order of Magnitude
Estimate Date:   [DATE]
Prepared by:     [NAME / FIRM — to be completed by cost manager]
Status:          DRAFT — Not for owner distribution until cost manager review

─────────────────────────────────────────────────────────────────────────
ELEMENTAL COST PLAN
─────────────────────────────────────────────────────────────────────────
[Elements table: # | Element | $/m² GFA | Quantity (m²) | Total ($) | Notes]

SUBTOTAL — CONSTRUCTION COST (ELEMENTS 1–20):       $XXX,XXX
─────────────────────────────────────────────────────────────────────────
CONTINGENCIES
  Design Contingency           [X]%     $XXX,XXX
  Construction Contingency     [X]%     $XXX,XXX
  Escalation Contingency       [X]%     $XXX,XXX

TOTAL CONSTRUCTION COST (INCL. CONTINGENCY):        $XXX,XXX
─────────────────────────────────────────────────────────────────────────
PROJECT COST ADDITIONS (excluded from GC contract — for reference only)
  Professional fees (design + QS)    [%]     $XXX,XXX
  Authority fees and permits                  $XXX,XXX (allow)
  FF&E and owner-supplied items               [Stated scope exclusion]
  Land (if applicable)                        [Not included]

TOTAL PROJECT COST (ORDER OF MAGNITUDE):            $XXX,XXX
─────────────────────────────────────────────────────────────────────────
COST RATE SUMMARY
  Construction cost / m² GFA:     $X,XXX / m²
  Construction cost / ft² GFA:    $XXX / ft²
─────────────────────────────────────────────────────────────────────────
ASSUMPTIONS AND EXCLUSIONS LOG
[Numbered list]

INFORMATION GAPS AND OPEN ITEMS
[Numbered list — items that must be resolved before upgrading to Class C]

COST MANAGER REVIEW BLOCK
This report is a DRAFT Class D estimate. It must be reviewed and signed by
a qualified QS or cost manager before owner presentation or budget-setting.
Reviewer: ________________   Firm: ________________   Date: ________
Signature: ________________

Phase 6 — Quality Gate

Before outputting the report, confirm:

• Every element with a significant cost driver has a stated assumption
• The estimate class (Class D) and DRAFT status are clearly labelled
• No element is marked "TBC" without a placeholder value and a corresponding open item
• The cost manager review block is present and unsigned

Key Rules

• Never present this estimate as a final tender price, guaranteed maximum price, or construction contract sum.
• Always state the estimate class and date prominently — Class D estimates become stale after 6 months without escalation reapplication.
• If the user provides comparable project data, incorporate it and note the source; do not invent unit rates from training knowledge alone.
• Ask one question at a time during intake. Do not front-load all questions.
• Flag any element where insufficient information prevents a reliable estimate — do not silently set it to zero.
• Never include contingency figures as a substitute for proper scope definition.

Output Format

Single markdown document structured per the Phase 5 template. Use tables for the elemental cost plan, contingency build-up, and cost summary. Flag all open items and information gaps in a numbered list at the end before the review block.

Feedback

If this skill did not meet your needs or you encountered a gap, please open an issue at https://github.com/archlab-space/Open-Skill-Hub/issues. Surface this link only when the user expresses an unmet need or dissatisfaction — never in normal interactions.