A construction estimate needs to explain what you are going to execute, how much work there is and how its price is formed. A global figure without scope may be useful for an initial conversation, but it leaves open questions when the client compares proposals or changes appear during execution.
This tour helps you convert plans, measurements and quotes into a valued catalog. You can apply it to a remodeling or a larger budget, adjusting the detail to the information available.
1. Define the scope and starting information
Gather plans, specifications, site visit and client requirements. Note access restrictions, schedules, working height, hauling and delivery conditions.
It also establishes what is left out: non-visible repairs, third-party work or customer supplies. If information is missing, record the assumption and its effect. For example: «The quote considers an existing support suitable to receive the finish; Additional repairs will be budgeted after evaluation.
Do not present a budget based on a preliminary project with the same degree of certainty as one supported by executive plans and verified measurements.
2. Organize chapters and line items
The chapters group related works: preliminaries, masonry, finishes and installations, for example. The line items describe activities that you can measure and value.
A useful line includes key, description, unit, quantity, unit price, and amount. An academic work hosted in the UNAM repository shows this structure in its section on elements of a construction budget. Source: academic document, section 3.2.
How to write a line item that can be priced
“Floor placement” leaves too many decisions open. Specify the type of finish, preparation of the support, adhesive, joints, cuts, cleaning and resources included, according to the work you will actually offer.
If a supply is quoted separately, indicate this. If you include it in the installed line item, check that it also appears in your analysis. The description and the unit price analysis must represent the same scope.
3. Measure quantities and retain supporting records
For each line item, record where the quantity came from: plane, axis, local, level, section or on-site measurement. The generators allow the dimensions and operations that support it to be left visible.
In a rectangular surface of 5 × 5 m, the area is 25 m². However, gaps, encounters and measurement limits are resolved according to agreed specifications and criteria. Do not adopt a discount rule without confirming that it applies to line item.
Maintain version and date of the plan. If dimensions change, you'll be able to identify how much needs to be updated without remeasuring the entire project.
4. Integrate unit prices with construction data
Analyzes the necessary resources per unit: materials, labor crew, machinery, tools and auxiliaries. Get comparable quotes and check to see if they include delivery, unloading and taxes.
Record prices in units compatible with consumption. If you buy a bucket and the analysis consumes liters, carry out the conversion with the effective presentation of the product.
The productivity rate deserves a review of its own. A labor crew can produce different quantities in a new construction with free fronts and in an occupied remodel with restricted access.
The unit price analysis example shows how to go from resources to selling price.
5. Integrate charges and define how to display taxes
After direct cost, determine the overhead, financing, profit and corresponding charges. Defines the basis of each percentage and preserves its support.
There are two presentations that you must distinguish: a catalog at direct cost with subsequent integration, and a catalog whose prices are already for sale. If your unit prices already includes overhead and profit, adding them back to the total doubles the charge.
Explicitly presents the currency and tax treatment. A proposal without VAT and another with VAT are not comparable solely by their total.
6. Calculate the amount and review the catalog
Line item amount = quantity × unit price.
The budget results from adding the line items within the defined scope, with the integration and taxes that you have established.
Example bill of quantities for a renovation
All the following values are hypothetical, expressed in MXN. The prices are assumed sales prices, already integrated and without VAT; They do not represent a quote or a market reference.
| Key | Line item summarized | Unit | Quantity | P.U. for sale | Amount |
|---|---|---|---|---|---|
| PRE-001 | Removal of floor finish, scope defined in specifications | m² | 25.00 | $90.00 | $2,250.00 |
| ACA-001 | Floor installed, with supply and placement of the exercise | m² | 25.00 | $450.00 | $11,250.00 |
| ACA-002 | Application of primer and paint on surface ready for coating | m² | 80.00 | $123.42 | $9,873.60 |
| Total of line items, without VAT | $23,373.60 |
The descriptions are abbreviated to explain the calculation. In the deliverable budget they must be expanded with their specifications. The price of paint takes up the didactic APU of the article on unit price analysis; The other two prices are assigned only to practice multiplication and addition. In this example, neither overhead nor profit are added back because the prices are presented as sales amounts.
7. Validate, deliver and retain a version
Before sending, please check:
- That each line item has a supported quantity and price.
- That the catalog and analysis units match.
- That there are no duplicate supplies or jobs.
- That scope, exclusions, validity and payment conditions are clear.
- That the total of the project file matches the report delivered.
Maintain a version of the submitted proposal. If the customer changes a finish, update the affected line item and document the difference from that version.
If you are choosing a tool for this process, consult what to check in software for construction estimates.
How to follow this workflow in KOSAN
In KOSAN you can create the work, organize chapters and line items, complete resources and build your APUs. Then you configure the economic integration, recalculate the project and prepare PDF or Excel reports.
Its versions and scenarios help maintain references before changing prices or scope. To continue during execution, the system includes estimation and work monitoring modules.
Frequently asked questions
What is the difference between a bill of quantities and an estimate?
The catalog orders line items, units and quantities. By incorporating prices and amounts, it becomes a valued catalog that is part of the budget. Check if the document also includes integration, taxes and commercial conditions.
Can I start with a budget per square meter?
It can serve as an approximation if you define type of work, quality, surface and exclusions. To value a specific scope and control changes, it is useful to break down line items and quantities in greater detail.
Should I add waste to the catalog quantities?
Distinguishes quantity of work and consumption of resources. If you budget 25 m² of finished floor, the waste of parts can be considered in the APU. Also inflating the m² of the catalog by the same waste can double it.
Discover how KOSAN works to organize the catalog, analyze prices and prepare reports for your next budget.
From unit price analysis to a construction estimate
Calculate the daily cost of labor with the labor burden factor (FSR) calculator. Then check how it integrates into a example work budget in PDF and Excel, with catalog, unit price analyses APU and resource breakdown.