Public Works Cost Estimating: How to Structure Quantities, Costs, BDI, and Risks

Learn how to structure public works estimates with quantities, SINAPI, SICRO, cost compositions, BDI, risks, assumptions, and procurement readiness.

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A public works estimate is the technical and economic representation of the scope the Administration intends to procure. It converts design, quantities, execution methods, productivity, inputs, logistics, labor burdens, indirect costs, risks, and local conditions into a value reference capable of supporting procurement, bid analysis, inspection, measurement, and future contract changes.

For this reason, an estimate should not be treated as a spreadsheet produced at the end of design. The quality of the estimated value depends on the maturity of the engineering that feeds it. Quantities extracted from incomplete design, cost compositions inconsistent with the execution method, unsuitable productivity rates, reference prices applied without contextual analysis, or an incoherent BDI can produce a figure that appears precise but is technically weak.

Under Law No. 14.133/2021, the previously estimated procurement value must be compatible with market prices, considering public databases, quantities, economies of scale, and site-specific characteristics. For construction and engineering services, the law establishes an order of parameters prioritizing SICRO for transportation infrastructure and SINAPI for other construction and engineering services, plus reference BDI and applicable labor burdens. The estimate is therefore simultaneously an engineering document, a procurement-planning instrument, and a control baseline.

The decisive question is not only “how much does the project cost?”. It is: does the estimate have sufficient maturity, traceability, and consistency to support the next public-investment decision?

A public works estimate is more than a price spreadsheet

The estimate is one of the central layers in the procurement control framework, connecting design, evaluation, measurement, and amendments. For the full lifecycle view, see What the TCU reviews in construction and engineering services procurement.

A spreadsheet may be mathematically correct and still represent the scope poorly. The problem arises when the estimate stops being understood as a consequence of the design and is treated as an independent collection of codes, quantities, and unit prices.

Within the logic of Capital Projects in Public Works, the estimate occupies an interface position. It receives information from the technical definition of the project and, at the same time, feeds procurement decisions, resource allocation, scheduling, risk, acceptability criteria, measurement, and control.

This means that a sound estimate needs to answer four questions together:

• what will be executed: scope, requirements, drawings, specifications, and limits;
• how much will be executed: traceable quantities and calculation records;
• how it will be executed: construction method, productivity, logistics, equipment, crews, and constraints;
• how much it costs under those conditions: unit costs, labor burdens, BDI, local prices, base date, and compatible risks.

If one of these dimensions is immature, the final value may convey a false sense of precision. It is common to find detailed spreadsheets with hundreds of items whose main uncertainty is not in the cents of each composition but in the scope definition itself or the quantities used.

The reference estimate should function as a traceable economic baseline. Each relevant item should be relatable to the design, specification, quantity record, cost composition, and corresponding measurement criterion.

The estimate needs to originate from the design and quantities

An estimate does not correct an insufficient design. It merely converts design insufficiency into cost uncertainty.

When a discipline is undefined, an interface remains open, or a field survey is incomplete, the estimator has to make an assumption to close the spreadsheet. The problem begins when that assumption is not recorded and starts to be interpreted as a contractual fact.

In the public sector, this weakness has a chain effect. An underestimated quantity may artificially reduce the procurement value. An overestimated quantity may undermine value for money. An omission may reappear as a scope change. A generic description may cause bidders to price different solutions under the same item.

For this reason, the relationship between Basic Design and the estimate is structural. The level of design definition should allow the necessary work to be identified, quantities to be measured using consistent criteria, interfaces to be understood, and a basis for cost formation to be established.

The quantity record should make it possible to identify where each relevant number came from. Depending on the scope, this may involve:

• areas, volumes, lengths, and units extracted from drawings;
• equipment and material lists;
• calculation memoranda;
• BIM models and quantity schedules;
• as-built surveys and Site Surveys;
• technically justified waste factors;
• transport distances;
• earthwork volumes;
• quantities for temporary works;
• consumption rates, productivity rates, or equipment cycles;
• phasing assumptions and interference with existing operations.

The link between design and estimate also facilitates review. When a quantity changes, it should be possible to identify which design revision caused the change, which item was affected, and what effect occurred on cost and schedule.

In multidisciplinary projects, the review also needs to look for overlaps and gaps among disciplines. Electrical infrastructure included simultaneously in the civil and electrical packages, excavation considered in more than one composition, supplies included in equipment and again in installation, or omitted auxiliary systems are examples of failures that are difficult to detect by looking only at the total value.

How a construction estimate is technically developed

A useful decomposition of the estimating process combines three classic stages — quantity takeoff, unit costs, and price formation — with additional design, risk, and readiness controls.

The flow appears linear, but in practice there is feedback. While developing the estimate, design gaps may emerge. A cost composition may reveal that the planned method requires access that does not exist. The price of equipment may make it necessary to revisit the technical alternative. An aggressive schedule may require more crews and alter the assumed productivity.

For this reason, estimate and design mature together.

Quantity takeoff

Quantity takeoff converts the technical solution into measurable units. It is not enough to know that there will be concrete, cable tray, fiber optics, electrical panels, paving, or automation. It is necessary to define exactly what will be measured, in which unit, under which criterion, and with what scope boundary.

A robust quantity record should state formula, source, unit, applied factor, and document reference. For relevant items, the reviewer should be able to reproduce the result without depending on informal knowledge held by the spreadsheet author.

Unit-cost composition

The composition represents the resources required to execute one unit of work. Materials, labor, equipment, and their productivity rates need to reflect the assumed execution method.

A composition should not be treated as immutable code. Reference systems are essential, but alignment between the reference and the actual work needs to be verified. A small difference in description may hide a large difference in productivity, equipment, thickness, strength, reach, logistics, or execution conditions.

Reference-price formation

After direct costs are consolidated, the elements applicable to price formation are added, including BDI, labor burdens, and scope-specific conditions. The result needs to maintain traceability so that the Administration knows not only the total value but how it was formed.

Law 14.133: the estimated value must represent market, quantity, and context

Article 23 of Law No. 14.133/2021 establishes that the previously estimated value must be compatible with market prices, considering prices in public databases, quantities, economies of scale, and characteristics of the execution site.

For construction and engineering services, the law organizes the parameters in an order of priority. The first is unit-cost composition based on SICRO for transportation infrastructure or SINAPI for other construction and engineering services. It then allows other sources, such as published research, formally approved tables, specialized websites, similar Administration contracts, and the national electronic-invoice database, subject to applicable legal conditions.

This order has a practical consequence: price research does not automatically replace Cost Engineering. For a composite service, obtaining only a final supplier quote may make it difficult to understand productivity, resources, logistics, tax incidences, and scope boundaries.

The same Article 23 provides specific treatment for integrated and semi-integrated contracting. Under these regimes, the estimate may combine a summary estimate, reference systems, and, for portions not yet sufficiently detailed in the preliminary design, rapid or parametric methods and similar procurements.

This reinforces a maturity rule: the estimating methodology must be compatible with the available level of definition. It makes no sense to demand the same precision from a preliminary design as from a detailed design; nor is it technically acceptable to present as a detailed estimate a value built on still-conceptual definitions without making uncertainties explicit.

SINAPI, SICRO, and other references: using a cost database is not copying a price

O SINAPI is Brazil’s primary national reference for construction costs and is maintained by CAIXA in partnership with price research conducted by IBGE or, according to the 2026 regulatory update, by an equivalent research agency. The system documentation includes methodology, calculations and parameters, technical booklets, input sheets, and monthly reports.

For transportation infrastructure, SICRO, maintained by DNIT, is the central reference. Its structure includes methodology, labor, pricing, site facilities, local administration, mobilization, and demobilization manuals, as well as technical booklets and mechanical-crew production rates.

Reference	Primary use	Required control
SINAPI	Construction and engineering services in general	check description, state, base date, composition, labor burdens, and technical booklet
SICRO	Transportation infrastructure	check methodology, region, crew production rates, equipment, transportation, and current parameters
Officially adopted proprietary systems	Situations provided for by the entity or applicable regulation	verify regulatory basis, scope, and compatibility
Market research	Items without an adequate reference or permitted situations	equivalent specification, sample, date, freight, taxes, and commercial conditions
Similar procurements	Support for estimating where legally applicable	update date and compare scope, location, quantity, and conditions

Decree No. 7,983/2013 allows local or project-specific conditions to be considered in cost compositions, provided the relevance of the adjustment is demonstrated in a technical report prepared by a qualified professional. This provision is technically significant: the official reference does not eliminate the need for engineering; it creates a baseline that must be applied correctly.

A SINAPI price may not automatically represent a situation involving severe access restrictions, night work, an occupied environment, special safety requirements, small scale, complex lifting, unusual logistics distance, or productivity materially different from the reference. The solution is not to abandon the system; it is to technically justify the adjustment where appropriate.

In March 2026, CAIXA published an updated edition of SINAPI — Methodologies and Concepts, emphasizing that table data and examples do not replace the current values in reports, technical booklets, and specification sheets. This distinction avoids a frequent error: using old methodological material as though it were a current price table.

Quantity takeoff is a technical decision, not merely a mathematical operation

A large share of estimating risk lies in quantity, not unit price.

If an item costs BRL 100 per unit and the correct quantity is 10,000, a 1% price error represents BRL 10,000. A 20% quantity error represents BRL 200,000. In complex projects, quantity uncertainty may also be concentrated precisely in the most expensive items.

Quantity takeoff should therefore have its own controls.

A robust review verifies:

1. whether all design elements have a corresponding estimate item;
2. whether all spreadsheet items have an identifiable technical source;
3. whether units of measure are consistent;
4. whether waste, allowances, and factors have been justified;
5. whether there are no overlaps among disciplines;
6. whether the contractual measurement method is compatible with the method used for quantity takeoff;
7. whether design revisions have been reflected in the spreadsheet;
8. whether provisional or conditional items are treated transparently.

Compatibility between quantities and measurement is particularly important. If the estimate was developed in one unit and the contract intends to measure in another, the Administration may create future control difficulties or an unintended transfer of risk.

Direct costs, indirect costs, and the BDI boundary

A distinção entre direct and indirect costs is not merely an accounting distinction. It affects transparency, measurement, bid comparison, and prevention of duplication.

Costs directly related to execution and capable of identification and measurement should be treated according to the applicable methodology. Local administration, site facilities, mobilization, and demobilization require attention because they may be improperly included in BDI or simultaneously included in both the spreadsheet and BDI.

In Decision 2,622/2013-Plenary, the TCU consolidated reference parameters for BDI analysis and reinforced that costs directly related to the scope and identifiable in the direct-cost spreadsheet — such as local administration, site facilities, and mobilization/demobilization — should not be hidden in the BDI rate.

This separation improves contract governance. A direct cost may have its own measurement criterion and traceability. When everything is indiscriminately aggregated into a rate, it becomes more difficult to understand how changes in schedule, quantity, or method actually affect the price.

BDI: a reference rate is not a universal percentage

BDI — Benefits and Indirect Expenses — is an essential component of price formation, but also one of the areas where simplifications create the most errors.

There is no single correct percentage for every project. Project type, corporate structure, risk, insurance, guarantees, financial expenses, taxes on revenue, and other conditions influence its composition according to the applicable methodology.

The ranges in Decision 2,622/2013 are references for analysis, not authorization to automatically select the median of a table and apply it to any scope. The composition must be consistent with the specific procurement and current tax legislation.

This point is especially sensitive because tax and financial parameters change over time. DNIT itself updates SICRO BDI references when relevant conditions change. In August 2026, for example, there was a new update associated with the Selic rate used in the system methodology.

For estimate governance, the important point is to preserve the calculation record: which components were considered, which rates were used, the base date, the assumptions, and the technical justification.

Location, logistics, and productivity can materially change cost

Two graphically identical projects may have very different costs when executed in different locations.

Supplier distance, labor availability, rainfall regime, traffic, access, accommodation needs, equipment transport, work-hour restrictions, building occupancy, operational safety, and availability of site areas affect productivity and logistics.

Law 14.133 requires site-specific characteristics to be considered; Decree 7,983 permits technically justified adjustments to references. The estimate needs to translate this legal requirement into engineering criteria.

An appropriate composition should investigate, where relevant:

• origin and transport distance of materials;
• need for special freight;
• loading and unloading restrictions;
• transport cycles;
• productivity loss due to interference with existing operations;
• work at height, classified areas, or critical environments;
• shutdown windows;
• climate seasonality;
• mobilization of specialized crews;
• need for support equipment not included in the standard composition.

These conditions do not justify arbitrary adjustments. They justify analysis and documentation.

Base date, estimate updating, and contract escalation must be distinguished

An estimate represents prices at a specific base date. This information is essential for interpreting the value and comparing it with bids received at another time.

A properly prepared estimate may become inadequate if it remains unchanged for a long period in a market subject to material variations. Governance therefore needs to record the dates of the references and assess the need for updating before tender publication.

It is also necessary to distinguish three concepts:

• estimate base date: the economic point in time represented by the costs used;
• estimate updating: review of the estimate before procurement, when necessary;
• contract price adjustment: a mechanism applied during execution according to contractual and legal rules.

Mixing these concepts can lead to incorrect comparisons among the estimate, bid, and contract.

ABC Curve: where to focus cost review

In a spreadsheet with hundreds or thousands of items, not all represent the same economic risk. The ABC Curve of inputs and services helps identify the components that account for the largest share of value.

The ABC Curve should not serve merely to produce a chart. It guides the validation effort.

Items in the highest-value range deserve deeper review of:

• quantities;
• specifications;
• cost composition;
• productivity;
• prices of relevant inputs;
• freight;
• differentiated BDI, where applicable;
• volatility risk;
• market availability;
• impact of a potential scope change.

This prioritization is consistent with the materiality logic used in auditing. Deeply reviewing what concentrates value tends to provide greater economic protection than dedicating the same effort to every item indiscriminately.

Summary, detailed, and parametric estimates serve different functions

A recurring error is comparing methodologies as though one were always superior to another. In reality, each estimate level supports a different decision.

Type	Typical function	Basis	Main limitation
Parametric	Early studies, comparison of alternatives, and permitted checks	indicators from similar projects, metrics, and typologies	lower resolution for specific items
Summary	Consolidation of work, quantities, and unit prices	design/preliminary design + reference systems	depends on the quality of compositions and quantities
Detailed	Detailed record of resources and productivity	cost compositions, inputs, labor, and equipment	requires greater maturity and technical effort

Law 14.133 allows parametric methodology in specific integrated or semi-integrated contracting situations for portions not yet sufficiently detailed in the preliminary design. Decree 7,983 also governs cases of parametric analysis in transfers involving federal funds.

The engineering principle is simple: do not assign greater precision than the available information allows.

A conceptual estimate should state its level of uncertainty and assumptions. As the design matures, the estimate needs to be replaced by one compatible with the new level of definition.

Risks, assumptions, and uncertainties need to be visible before procurement

An estimate almost always contains uncertainty. The problem is not that uncertainty exists; it is hiding it within the number.

Assumptions need to be recorded. Relevant risks need to be associated with the risk matrix and procurement strategy. Items that are not yet defined need to be resolved or treated consistently with the selected regime.

An estimate risk analysis should look for, among other points:

• incomplete or outdated design;
• quantities without supporting records;
• relevant items without an appropriate reference;
• market prices based on different specifications;
• productivity inconsistent with the site;
• omitted freight or logistics;
• double counting between direct cost and BDI;
• failure to consider interfaces among disciplines;
• long-lead equipment without a pricing strategy;
• schedule inconsistent with assumed productivity;
• outdated taxes or labor burdens;
• risks transferred to the contractor without sufficient information for pricing;
• measurement criteria inconsistent with price formation.

The connection with Engineering Risk Management is direct. Cost and risk are not independent disciplines: uncertainties in scope, quantity, schedule, and execution method become economic exposure.

The schedule is also an input to the estimate

Cost and schedule interact.

Local administration, rented equipment, site facilities, mobilization, support crews, and financial expenses may change when duration changes. At the same time, an attempt to shorten the schedule may require parallel crews, additional shifts, or different construction methods.

For this reason, estimate and schedule need to share the same assumptions.

A frequent inconsistency occurs when the estimate assumes productivity compatible with one crew while the schedule requires three simultaneous work fronts to meet the date. The calculated cost belongs to one strategy; the schedule belongs to another.

In more complex projects, integration between Cost Engineering and Project Controls makes it possible to verify whether quantity, duration, resources, and disbursement form a coherent baseline.

Estimate readiness: when is it ready to support procurement?

Having a spreadsheet, cost compositions, and BDI does not mean the estimate is ready for procurement.

Readiness needs to assess the package as a system. Design, estimate, schedule, risk matrix, Terms of Reference, measurement criteria, and tender documents need to tell the same story.

Check	Expected evidence
Scope	design and specifications with clear boundaries
Quantities	reproducible records linked to the correct revisions
Cost compositions	alignment with execution method and the reference used
Prices	base date, source, and location recorded
SINAPI/SICRO	codes and technical booklets compatible with the work
Special items	technically justified market research or custom composition
BDI	calculation record and incidences without duplication
Labor burdens	current parameters and compatible regime
Risks	open assumptions identified and addressed
Schedule	productivity and duration consistent with cost
Measurement	units and criteria compatible with the spreadsheet
Tender documents	consistent acceptability criteria and documentation

This review is a genuine gate. If critical information is missing, the technically correct answer may be do not publish yet.

The Technical Review of Tender Documents and Attachments is particularly useful at this boundary because it cross-checks the estimate against the design, Preliminary Technical Study, Terms of Reference, schedule, risks, qualification, measurement, and acceptance.

The estimate influences bid analysis

After publication, the reference estimate ceases to be merely an internal planning instrument and becomes part of the economic evaluation logic of the procurement.

Under Law 14.133, the analysis of feasibility and overpricing in construction and engineering services considers the total price, quantities, and relevant unit prices, according to the criteria established in the tender documents. This makes baseline quality decisive.

If the estimate contains poorly described items or weak quantities, comparing bids becomes more difficult. A bid may appear more economical because it interpreted the scope differently, excluded a necessary resource, or adopted incompatible productivity.

For this reason, Technical Support for Procurement and Engineering Bid Analysis should look beyond the final price. Technical analysis can verify consistency among the bid, scope, quantities, solutions, documentation, and execution conditions.

The estimate baseline remains active during execution

The estimate does not lose usefulness after contract signature. It becomes a reference for measurement, change control, analysis of new prices, amendments, and trend monitoring.

When a design change arises, the first question should be: which technical and economic baseline is being modified?

Good governance records:

1. origin of the change;
2. affected design revision;
3. changed items and quantities;
4. price impact;
5. schedule impact;
6. effect on risks and interfaces;
7. responsibility for the change;
8. approval before execution, when applicable.

This linkage reduces the possibility of the contract accumulating changes without a consolidated view of their impact on the investment.

The service of Technical Analysis of Amendments, Scope Changes, and Claims uses exactly this logic: compare the contracted condition, modifying event, evidence, quantities, costs, and contractual effects.

Recurring errors in public works estimating

The most dangerous errors are not necessarily broken formulas. Many are interface errors.

Quantity without traceability

The spreadsheet presents a value, but no one can reproduce its origin. When the design changes, there is no way to know what must be updated.

Similar but non-equivalent reference code

The SINAPI or SICRO item appears close to the designed work, but it has different materials, productivity, equipment, or execution conditions.

Market research without technical equivalence

Three commercial quotations are not comparable when each supplier quoted a different specification, warranty, freight condition, lead time, or supply boundary.

BDI used as a repository for unresolved costs

Costs that could be directly identified are embedded in the rate, reducing transparency and increasing the risk of duplication.

Schedule inconsistent with the cost composition

The productivity used for pricing does not allow the assumed schedule to be met.

Low-quantity, high-criticality items ignored

An item may represent a small share of CAPEX and still control energization, safety, integration, or system acceptance.

Estimate updated without updating assumptions

Applying a monetary index to an old spreadsheet does not resolve changes in scope, technology, market, design, or input availability.

Technical responsibility and document governance

Engineering estimating requires technical competence and sufficient documentation to demonstrate the reasoning used. Federal regulation of reference costs itself provides for a technical report prepared by a qualified professional when local or project-specific adjustments are required.

In addition to the spreadsheet, the estimate package may include:

• quantity takeoff records;
• detailed cost compositions;
• BDI calculation record;
• labor-burden calculation record;
• market-research criteria;
• quotation comparison map;
• ABC Curve;
• base date;
• assumptions and exclusions;
• justifications for custom cost compositions;
• justifications for adjustments to references;
• linkage to design documents;
• applicable professional responsibility documentation.

The topic of ART, RRT, and TRT in public works should be addressed together with document governance for the package, respecting professional attributions and the instrument corresponding to the responsible professional.

How to procure a Cost Engineering service

When the public entity lacks sufficient internal capacity, engaging specialized estimating support may be more efficient than trying to correct the spreadsheet after the tender documents have been published.

The scope should be defined in a verifiable way. “Prepare an estimate” is insufficient as a service description if there is no clarity about inputs, level of detail, and deliverables.

The robust scope may include:

Inputs

• design or preliminary design and their respective revisions;
• design narratives and specifications;
• field surveys;
• schedule or schedule assumptions;
• risk matrix;
• location and execution conditions;
• applicable reference basis;
• requirements of the entity and funding program.

Activities

• audit of the inputs;
• quantity takeoff or validation;
• selection and review of cost compositions;
• price research for special items;
• productivity analysis;
• calculation of labor burdens and BDI;
• ABC Curve;
• cross-check against design and schedule;
• recording of assumptions and gaps;
• independent review of the estimate.

Deliverables

• summary estimate spreadsheet;
• detailed cost compositions;
• quantity takeoff record;
• BDI and labor-burden calculation record;
• price research and quotation map;
• ABC Curve;
• assumptions and justification report;
• inconsistency report;
• revised version after comments;
• editable files and controlled PDF;
• professional responsibility documentation where applicable.

Acceptance criteria

Acceptance should not be limited to delivery of the file. It is possible to verify whether quantities are reproducible, whether cost compositions correspond to specifications, whether references are identified, whether incidences are consistent, whether gaps were recorded, and whether the final version aligns with the approved design.

The Cost Engineering for Construction and Engineering Services can support both preparation and independent review of this economic baseline.

How A3A Engenharia structures estimating within the investment lifecycle

Within Engineering for Public Investments, the estimate is not treated as an isolated service. It is one of the pieces of evidence used to assess investment maturity.

The Assessment · Advisory · Assurance logic can be applied as follows:

• Assessment: verify design, quantities, documents, references, assumptions, and gaps that affect cost;
• Advisory: structure quantities, cost compositions, market research, BDI, schedule, and economic documentation;
• Assurance: independently review traceability, consistency, risks, and readiness before the next gate.

This model connects the estimate to the Preliminary Technical Study (ETP), Basic Design, Terms of Reference, risk matrix, tender documents, inspection, and acceptance.

The objective is to preserve continuity between what was technically defined and what will be contracted and paid.

Readiness checklist before approving the estimate

Before considering the estimate complete, it is worth answering objectively:

• is the design revision used identified?
• is the scope sufficiently defined for the procurement regime?
• is there a record of the relevant quantities?
• were the highest-impact items reviewed in depth?
• were SINAPI, SICRO, or another reference used according to applicability?
• do items without a reference have a technically justifiable custom composition or market survey?
• are the base date and location clear?
• do labor burdens and BDI have calculation records?
• were direct costs kept from being duplicated in BDI?
• are schedule and productivity consistent?
• are risks and assumptions recorded?
• are measurement criteria compatible with the spreadsheet units?
• are the design, Terms of Reference, estimate, risks, and tender documents consistent with one another?
• are editable files and evidence organized for future inspection?

If several answers are negative, the problem is not “spreadsheet formatting.” The package has not yet reached sufficient maturity.

Final considerations

Public works estimating is an engineering and governance discipline. Its value lies not only in estimating the procurement price, but in translating the design into a verifiable economic baseline capable of guiding decisions before and during execution.

SINAPI and SICRO provide fundamental references, but they do not replace surveys, design, quantities, execution-method analysis, local context, schedule, and technical judgment. BDI does not correct scope gaps. Market research does not correct insufficient specifications. A detailed spreadsheet does not correct an immature design.

The greater the commitment being made — reserving funds, publishing tender documents, awarding a contract, mobilizing, or approving a change — the greater the confidence required in the information supporting the decision.

The estimate is ready when it stops being merely a plausible number and becomes a traceable representation of what will be executed, under which conditions, with which resources, assumptions, and risks.

Technical references

[1] BRASIL. Lei nº 14.133, de 1º de abril de 2021. Public Procurement and Administrative Contracts Law. Disponível em: [Planalto — Lei nº 14.133/2021](https://www.planalto.gov.br/ccivil_03/_ato2019-2022/2021/lei/l14133.htm).

[2] BRASIL. Decreto nº 7.983, de 8 de abril de 2013. Establishes rules and criteria for preparing reference estimates for construction and engineering services contracted and executed with federal budget resources. Disponível em: [Planalto — Decreto nº 7.983/2013](https://www.planalto.gov.br/ccivil_03/_ato2011-2014/2013/decreto/d7983.htm).

[3] BRASIL. Decreto nº 12.867, de 5 de março de 2026. Amends Decree No. 7,983/2013 regarding maintenance of SINAPI and price research. Disponível em: [Planalto — Decreto nº 12.867/2026](https://www.planalto.gov.br/ccivil_03/_ato2023-2026/2026/decreto/d12867.htm).

[4] CAIXA ECONÔMICA FEDERAL. SINAPI — National System for Construction Cost and Index Research. Methodologies, technical documentation, and monthly reports. Disponível em: [CAIXA — SINAPI](https://www.caixa.gov.br/poder-publico/modernizacao-gestao/sinapi/Paginas/default.aspx).

[5] CAIXA ECONÔMICA FEDERAL. SINAPI — Methodologies and Concepts. Brasília, March 2026. Disponível em: [Livro SINAPI — Metodologias e Conceitos](https://www.caixa.gov.br/Downloads/sinapi-metodologia/Livro_SINAPI_Metodologias_Conceitos.pdf).

[6] DEPARTAMENTO NACIONAL DE INFRAESTRUTURA DE TRANSPORTES. SICRO — Reference Cost System for Works. Manuals, booklets, regulations, and reports. Disponível em: [DNIT — SICRO](https://www.gov.br/dnit/pt-br/assuntos/planejamento-e-pesquisa/custos-referenciais/sistemas-de-custos/sicro).

[7] DEPARTAMENTO NACIONAL DE INFRAESTRUTURA DE TRANSPORTES. Normative Instruction No. 10/DNIT Headquarters, October 9, 2024. Use of SICRO parameters to estimate the value of transportation-infrastructure construction and engineering services. Disponível em: [DNIT — IN nº 10/2024](https://www.gov.br/dnit/pt-br/central-de-conteudos/atos-normativos/tipo/instrucao-normativa/2024/instrucao-normativa-no-10-2024).

[8] TRIBUNAL DE CONTAS DA UNIÃO. Guidelines for Preparing Public Works Cost Estimate Spreadsheets. Brasília: TCU, 2014. Methodological reference; the legal basis should be read together with current legislation. Disponível em: [TCU — Planilhas Orçamentárias de Obras Públicas](https://portal.tcu.gov.br/publicacoes-institucionais/cartilha-manual-ou-tutorial/orientacoes-para-elaboracao-de-planilhas-orcamentarias-de-obras-publicas).

[9] TRIBUNAL DE CONTAS DA UNIÃO. Decision No. 2,622/2013-TCU-Plenary. Reference BDI parameters for construction and engineering services. Disponível em: [TCU — Acórdão 2.622/2013-Plenário](https://pesquisa.apps.tcu.gov.br/documento/acordao-completo/%2A/NUMACORDAO%3A2622%20ANOACORDAO%3A2013%20COLEGIADO%3A%22Plen%C3%A1rio%22/DTRELEVANCIA%20desc%2C%20NUMACORDAOINT%20desc/0).

Frequently asked questions

What is a public works estimate?

It is the technical and economic representation of a construction project or engineering service that consolidates scope, quantities, cost compositions, input prices, labor burdens, BDI, assumptions, and execution conditions to form the procurement reference value.

Is SINAPI mandatory for every public works project?

Not indiscriminately. Under Law 14.133, for construction and engineering services, Article 23 prioritizes SICRO for transportation infrastructure and SINAPI for other construction and engineering services. States, the Federal District, and municipalities without federal funds may use other cost systems adopted by the respective entity, subject to applicable law and regulations.

What is the difference between a summary estimate and a detailed estimate?

A summary estimate presents work items, units, quantities, and unit prices in consolidated form. A detailed estimate breaks down the resources and coefficients forming each unit cost, such as materials, labor, equipment, and productivity.

What is BDI in a public works project?

BDI is the Benefits and Indirect Expenses component applied in price formation. Its composition should consider the components applicable to the procurement and avoid duplication with costs directly identifiable in the spreadsheet.

Can a SINAPI or SICRO cost composition be adjusted?

Where technically appropriate and legally permitted, references may require adjustment to local or project-specific conditions. Under Decree 7,983/2013, the relevance of adjustments must be demonstrated in a technical report prepared by a qualified professional.

When is an estimate ready for procurement?

When the design, quantities, cost compositions, prices, BDI, labor burdens, risks, schedule, measurement, and procurement documents have sufficient consistency and traceability for the market to understand and price the scope on a comparable basis.

Who can prepare or review a public works estimate?

Responsibility must respect professional attributions and regulations applicable to the scope. For engineering services, the Administration should ensure technical capability, methodology documentation, and professional responsibility compatible with the work performed.

Complementary technical materials

Related services

• Cost Engineering for Construction and Engineering Services
• Technical Planning for Engineering Procurement
• Technical Review of Tender Documents and Attachments for Engineering Procurement
• Design Review in Engineering Projects
• Engineering Risk Management
• Technical Support for Procurement and Engineering Bid Analysis

Main content on the topic

• Capital Projects in Public Works: structuring public investments from need to operation
• Reference Estimates and Price Research for Construction under Law 14.133
• SINAPI: what it is, how it works, and how to use it in construction estimates
• Direct and Indirect Costs in Construction
• ABC Curve of Construction Inputs

Related technical content

• Preparatory Phase of Public Works Procurement
• ART, RRT, and TRT in Public Works
• Public Works Management: preventing stoppages, protecting investment, and reducing manager risks
• 7 Maturity Gates for Public Engineering Investments