What the tool does
Before there are drawings to measure, a budget is set from a few facts about the building. This tool turns those facts into an elemental cost plan: foundations, frame, facade, roof, interiors, services and sitework, each with a quantity, a unit, your rate and an amount. Every quantity shows how it was worked out, so the person reading the estimate can check it.
Estimates are kept in this browser on this device. Nothing is uploaded.
Where it fits in a project
Clients, architects, cost consultants and public building officers need a cost early, to decide whether to go ahead, how big to build and which structure or facade to choose. Paid cost databases charge a yearly subscription, and the estimate itself is usually kept in a spreadsheet. This tool keeps the spreadsheet logic in one place and writes it back out as a spreadsheet with live formulas.
Inputs and quantities
The building is described by its footprint (a rectangle, or an area with its perimeter), the storeys above and below ground, the storey heights, the window share of the facade, the number of exterior doors and the site area, in metric or imperial units. From these the tool works out:
- gross floor area = footprint x all storeys;
- suspended floors = gross floor area - footprint, and roof, slab on grade and standard foundations = footprint;
- exterior walls = perimeter x storey height x storeys above ground x (1 - window share), and exterior windows the window share of the same facade area;
- basement walls = perimeter x basement storey height x basement storeys, and basement excavation = footprint x basement storey height x basement storeys;
- interior construction, finishes and services per m² (or sf) of gross floor area, and sitework on the site area outside the footprint.
Any quantity can be overwritten. The elements follow UNIFORMAT II (ASTM E1557), with the element list and the quantity-per-floor-area approach of NIST IR 6389. The tool reproduces the quantities of that report's worked example of an eight-storey office building (54,000 sf of gross floor area). The same estimate can also be grouped by Korean work sections for reference.
Rates, markups and factors
Rates are entered by you, with a note on where each rate comes from, because published cost data is either paid or not licensed for reuse. Useful sources are your own past projects, a cost database you subscribe to, and public data such as the building-type costs of the Korean Public Procurement Service. A rate library keeps your rates in the browser for the next estimate.
Markups (general conditions, overhead and profit, contingency, escalation, tax or any others) are applied in order on the running total. A location factor and two cost index values move rates to another place and date: the factor is shown as location x current index / index of the rates.
Options, benchmark and sensitivity
Copy an option to try another structure, facade or height; the options are compared side by side with gross floor area, total and cost per m². Enter a low and high cost per m² from a published source to see whether the estimate falls inside the range. A small table shows the total with two storeys fewer or more.
Files
- Excel (XLSX): one sheet per option with the building inputs at the top, the derived quantities as formulas of those inputs, each element's quantity as a formula of the derived quantities, amounts, markups and totals, group subtotals, and a sheet comparing the options. Change the number of storeys in Excel and the whole estimate follows. Written with ExcelJS.
- PDF: a one-page summary per option.
- Schedule: the element groups with their amounts as activities for the schedule tool on this site, to start a cost-loaded programme.
- CSV and the project file (JSON).
Limits
A conceptual estimate is for early decisions and carries a wide range of uncertainty; it is not a bid or a contract price. Quantities from ratios assume a simple building form, so stepped, curved or very irregular buildings need overwritten quantities. The sample estimate uses illustrative rates that are not published data.
Last checked 2026-10-19