How to Contract the Construction of an Industrial Building

Two companies can build the same industrial facility, in the same park and from the same design, yet end with very different financial results. The difference is rarely the price shown in the first proposal: it lies in who absorbed what had not yet been resolved on the day the contract was signed. The geotechnical study that arrived later. The equipment load that operations had not yet confirmed. The electrical service that depended on the industrial park rather than the contractor.

None of that disappears when a number is written into a contract; it merely changes owners. Contracting well means deciding, before signing, who owns each issue and what happens when an assumption fails. That requires separating two decisions that meetings almost always treat as one.

Two different decisions that are often confused

The contracting discussion commonly combines two independent questions:

The delivery model. Who is responsible for design, who is responsible for construction, how many contracts are involved, and when the contractor joins the project.
The payment arrangement. How compensation is calculated: a fixed sum, payment per completed unit of work, documented cost plus a fee, or a capped combination.

They are separate layers. The Construction Management Association of America treats them precisely that way: compensation methods do not belong to any single delivery model and may apply to professional services as well as construction. Confusing them produces invalid comparisons because the proposals being contrasted actually describe different allocations of risk.

Delivery models and what changes for the owner

Many variations are used, but almost all derive from a few basic configurations.

Design-bid-build. The owner first contracts for the construction documents and, once they are complete, bids the work. This is the most linear arrangement and makes it possible to compare proposals against a common scope; in return, the contractor provides no input during design, and the owner remains at the center of any discrepancy between the drawings and execution.
Multiple prime contractors. The owner signs directly with several specialty contractors. The owner gains control and cost visibility by work package while assuming coordination among them, which is where sequencing and interface conflicts commonly arise.
Construction manager at risk. The builder joins as an adviser during design—estimating, scheduling, and constructability review—and later assumes the role of general contractor, normally committing to a price ceiling before the design is fully complete.
Design and construction under a single contract. One party is responsible for both design and construction. This reduces contractual interfaces and allows stages to overlap; it requires a much firmer owner's project requirements document because that will be the reference against which the completed work is judged.
Integrated delivery. Owner, designer, and builder share an agreement with aligned incentives and collaborative decision-making. It requires contractual maturity and a willingness to manage the project jointly.

None is inherently superior. What changes is when the owner receives reliable cost and constructability information and how much coordination remains under the owner's responsibility. The Build-to-Suit model and the capability review described in how to choose an industrial construction company rely on the same logic.

Payment arrangements: the risk transferred by each one

Within Mexico's public-works framework, Article 45 of the Law of Public Works and Related Services establishes that payment terms may be agreed on the basis of unit prices, a lump sum, or a mixed arrangement. That law governs public procurement, not private construction, but it established the vocabulary the Mexican industry uses every day, and that vocabulary should be used precisely.

For private construction—which is the case for practically every industrial building in Querétaro—the applicable framework is not that law but the lump-sum construction contract regulated by civil codes. The Federal Civil Code devotes a complete chapter to it beginning with Article 2616, with rules worth understanding before negotiations begin: the risk of the work remains with the contractor until delivery, except when the owner is in default for failing to receive it or the parties expressly agree otherwise; a fixed-price agreement for real property must be in writing, with a detailed description and, where required, a drawing, design, or budget; and a contractor who undertook the work for a fixed price is not subsequently entitled to demand an increase, even if material costs or wages rise. That final rule expressly extends to changes or additions to the drawings unless the owner authorizes them in writing and expressly identifies the price.

It is worth pausing over those rules because they explain much of what follows in this article: Mexican civil law already assumes that a lump sum rests on a detailed description, and it assumes that every change is documented in writing at an agreed price. What feels like bureaucracy in practice is actually the condition that makes the fixed price enforceable. Private contracting in Querétaro is governed by the state's civil code and, when the transaction is commercial, by commercial law; the articles applicable to each case must be verified with legal counsel.

Payment arrangements and their allocation of risk
Arrangement	How payment is made	Who absorbs the variance	What it requires from the owner
Lump sum	A fixed sum for fully completed work within the agreed period	The contractor, within the contracted scope	A closed, documented scope before signing
Unit prices	Per unit of completed work, based on a bill of quantities	The owner, because quantities are measured in the field	The ability to measure, verify, and control quantities
Mixed	One part as a lump sum and another at unit prices	Allocated according to the work item	Clear definition of which activity belongs to each method
Construction management or cost-reimbursable	Documented cost plus a fixed or incentive fee, or payment for time and materials	The owner	Cost auditing and explicit substantiation rules
Guaranteed maximum price	Documented cost subject to a ceiling that cannot be exceeded	The contractor above the ceiling; the owner below it	Define the disposition of savings and the content of included allowances and contingencies

The table combines two vocabularies, which should be made explicit: the first three rows use the terminology of the Law of Public Works and Related Services, while the final two use terminology from international practice. They are not equivalent taxonomies. In the Construction Management Association of America's classification, for example, unit prices are themselves a type of cost-reimbursable contract, together with cost plus a fixed fee, cost plus an incentive fee, and time-and-materials payment. They are separated here because unit prices operate as their own category in Mexico, with measurement rules and a bill of quantities.

The guaranteed maximum price deserves careful reading. It usually combines a base cost with allowances and contingencies that, depending on how they are used, may leave the final cost below the cap; whether those remaining amounts belong to the owner or are shared is a matter for negotiation and must be stated in writing. A cap without savings rules is not really a cap: it is a ceiling with ambiguous incentives.

A fixed price is fixed only when the scope is fixed

The most frequent cause of conflict is not the selected arrangement but a request for a firm commitment based on an immature definition. AACE International's Recommended Practice 56R-08—which applies to building and general construction, rather than the process-industries practice that excludes this type of work from its scope—classifies cost estimates into five classes and establishes that the maturity of the project definition deliverables is the defining characteristic of the class. The percentage of definition often used to summarize that maturity is merely an approximate indication, not the criterion. Intended use of the estimate, estimating methodology, and expected accuracy range are secondary characteristics: they correlate with maturity but do not replace it.

The practical consequence is direct. Estimates with minimal definition are used to screen concepts and size functional areas. Intermediate-definition estimates accompany design development, feasibility analysis, and budget authorization. Only advanced-definition estimates are appropriate for control, bidding, or a check estimate.

The middle point deserves emphasis because it is the one most often misunderstood: in building construction, feasibility is not resolved with minimal definition. It already requires an intermediate level, the same level at which the budget is authorized. When management asks for a number “to see whether the project is viable” based on a site-layout sketch, it is not asking for a feasibility estimate; it is asking for concept screening and treating it as something else. Requesting a lump sum from a concept design does not eliminate uncertainty; it turns uncertainty into assumptions the contractor must cover in the price or into claims that will appear later.

When the required start date forces design and construction to overlap, the honest approach is not to pretend there is a fixed price. It is to choose an arrangement that manages uncertainty—mixed, guaranteed maximum price, or packages closed as they mature—and clearly state which part of the scope remains undefined.

What must be defined before requesting a firm price

The list varies by project, but a bid package for an industrial building is unlikely to support a firm commitment without resolving these points:

Operations and layout. Process, flows, storage, planned growth, and support areas, following the criteria of the validated industrial layout.
Structural geometry. Clear height, spans and column grid, roof loads, suspended loads, and provisions for equipment.
Site conditions. Geotechnical study, topography, elevations, and earthwork quantities that define the foundation solution.
Floor. Loads, flatness, joints, and finish, decided against actual use rather than unit cost, as explained in the guide to industrial floors.
Building systems and capacities. Electrical demand and point of supply, water, drainage, compressed air, fire protection, and data infrastructure.
Envelope and roof. Systems, insulation, natural lighting, stormwater drainage, and sealing details.
Boundary with the industrial park. Which site infrastructure, utility service points, access, and exterior work are included and which are the developer's responsibility.
Regulatory and approval framework. Which procedures each party assumes, as described in permits and procedures in Querétaro.
Acceptance criteria. The tests, evidence, and documentation that will define technical handover.

A project coordinated in BIM helps detect clashes before they become extra work items, but it does not replace operations' decision about what the building requires.

Where the money actually moves: scope changes

Final cost is rarely decided at signing; it is decided through change management. Typical causes are recognizable and largely foreseeable:

Incomplete definition at the time of contracting.
Site conditions that differ from those anticipated in the studies.
End-user changes driven by evolution of the process, equipment, or commercial program.
Requirements from authorities, insurers, or corporate teams that emerge during review.
Availability of long-lead materials or equipment that forces substitution or resequencing.

A controlled project is distinguished not by the absence of changes but by a procedure agreed upon from the beginning: who may request them, who prices them, which pricing basis applies, how quickly a response is required, how the schedule effect is documented, and who authorizes them. Unit-price analyses for the most likely work items and the rule for adding extra items should be agreed in advance; negotiating them while construction is stopped puts the owner in the worst possible position.

A change authorized verbally and executed without a record creates two problems: no one knows exactly what is being paid for, and no one knows exactly what is being received. Both surface at closeout, when there is no longer room to correct them.

Estimate contingency and the owner's reserve are not the same

It is useful to separate two funds with different owners and rules:

Estimate contingency. This covers variability inherent in an already defined scope: productivity, unresolved details, and identified risks within the contracted work. It sits within the construction budget and is released against verifiable events.
Management reserve. This covers matters that do change the scope: business decisions, new requirements, and improvement opportunities. It is managed by the owner and should not be consumed to conceal execution variances.

Mixing them produces a familiar result: contingency is exhausted in the first few months, and every later change becomes a dispute over responsibility instead of an investment decision. A monthly report showing committed amount, amount spent, approved changes, pending changes, and the balance of each fund is worth more than a detailed budget that no one updates.

Economic clauses that define the relationship

Beyond the payment arrangement, the contract's behavior depends on a handful of clauses that should be reviewed with legal counsel and finance, not only the technical team. They do not all carry the same weight, and treating them as a uniform checklist is the most common way to negotiate poorly: some govern cash flow every month, others activate only when something goes wrong, and one determines what remains with the owner after the project ends.

Those that operate every month. Advance payment, its permitted use, and amortization; frequency of payment applications, supporting-document requirements, and payment period; retainage or warranty fund and the conditions for its return; and, if the project permits it, treatment of cost adjustments when input prices vary. These are the provisions the field and finance teams use from the first payment application, so they deserve the highest level of detail. An ambiguous rule here does not wait for a dispute: it creates friction every month and wears down the relationship before the first real technical problem appears.

Those that matter only if something fails. Warranties, surety bonds, or equivalent instruments for the advance payment, performance, and latent defects; liquidated damages and their relationship to delay causes attributable to each party; builder's risk and liability insurance, with verified coverage and effective periods; and the rules for suspension, early termination, and dispute resolution. They are negotiated quickly precisely because no one expects to use them, and that is the risk. Liquidated damages without an agreed method for attributing delays are often unenforceable in practice. A bond that expires before the latent-defect period does not cover what it was purchased to protect.

The one that survives the project. Ownership and use of drawings, models, and technical information. It is the clause that attracts the least discussion at signing and carries the greatest weight later: without it resolved, an expansion, operator change, or audit begins by reconstructing information the company already paid for once.

These clauses must be drafted for the specific project and in accordance with applicable law; their specific content is for each party's advisers to define.

How to select: price, qualifications, or best value

CMAA describes three award approaches: price-based, qualifications-based, and best value, which combines both. It also distinguishes one-stage from two-stage processes, in which qualifications are evaluated first and the price proposal is received afterward.

The selection method must correspond to scope maturity. Awarding to the lowest price makes sense when the technical package is complete and every proposal prices exactly the same work. When the scope remains open to interpretation, the lowest price tends to come from the bidder who read the project least carefully, and the difference reappears as change orders. A two-stage process makes it possible to screen for actual capability—equivalent industrial experience, staffing, quality control, financial strength, and safety—and then compare prices among comparable proposals.

When proposals are tabulated, they should be normalized: the same scope, exclusions, site and utility assumptions, payment terms, and schedule. A table that compares totals without reviewing exclusions compares nothing.

A practical decision path

Define operational requirements and the level of flexibility the business needs to retain.
Assess honestly the maturity of the technical definition and what remains to close it.
Select the delivery model according to how much coordination the company can and wants to manage.
Select the payment arrangement—or combination—that matches that maturity, not the desire for a fixed number.
Prepare a bid package with scope, specifications, acceptance criteria, and schedule.
Select on qualifications and price using normalized proposals.
Establish the change procedure, cost report, and separation of contingency and reserve from day one.
Finalize the contract with acceptance and documentation rules already agreed upon.

Common mistakes

Requesting a fixed price for an open design. This moves uncertainty into hidden assumptions or future claims.
Comparing totals without comparing exclusions. The least expensive proposal is often the one that includes the least.
Failing to agree on pricing bases for extra work. This forces negotiation at the worst possible moment.
Using contingency to fund scope changes. This leaves the project with no cushion for actual risks.
Authorizing changes without a record. This breaks traceability of cost and of what was actually built.
Treating the contract as a filing document. A contract no one consults during construction protects neither party.

Contracting well is not about transferring every risk to the contractor or retaining every risk for the sake of control. It is about placing each risk where the best information exists to manage it and documenting that allocation before the risk occurs. That decision is made during the construction process, shapes the project's actual cost, and determines whether a future expansion begins with a reliable record or with an effort to reconstruct the project's history.

To define a design and construction proposal, review the scope with Grupo COB’s sales team. The technical discussion helps clarify deliverables and exclusions; legal drafting and contract review remain the responsibility of each party’s advisers.

Technical references consulted

Chamber of Deputies: Law of Public Works and Related Services, Article 45 (last amended in the Official Gazette of the Federation on November 14, 2025).
Chamber of Deputies: Federal Civil Code, chapter on Lump-Sum Construction Contracts, Article 2616 et seq. (last amended in the Official Gazette of the Federation on November 14, 2025).
Construction Management Association of America: An Owner's Guide to Project Delivery Methods (2012).
AACE International: Recommended Practice 56R-08, Cost Estimate Classification System – As Applied in Engineering, Procurement, and Construction for the Building and General Construction Industries (rev. August 7, 2020).

These references were consulted as process guides. The Law of Public Works and Related Services governs federal public procurement and is cited here for its conceptual and terminological value; private contracting is governed by applicable civil and commercial law, which at the local level means each state's civil code. The Federal Civil Code is therefore cited as a reference for the contractual concept, not as a rule directly applicable to private construction in Querétaro. The contractual, technical, and tax criteria for each project must be defined with the appropriate advisers and authorities.