Time extensions on Mexican public works: how to request one and what backup it takes
Last reviewed: Regulations change: the text is checked against the official source at each review.
A time extension is the formal extension of the completion date of a construction contract, arising from causes that prevented the work being executed under the schedule. On Mexican federal public works it is formalised through a convenio, and article 59 of the LOPSRM governs the grounds and the limits for modifying contracts.
The practical rule that sums the whole thing up: an extension is not won when it is requested, it is won when it is documented. By the time you file the request, either the backup already exists or it can no longer be built.
What causes support one
The causes that typically ground an extension lie outside the contractor:
- Late handover of the site, of work fronts or of working areas
- Technical information that is incomplete, late or contradictory
- Agency-supplied materials that do not arrive
- Suspension of work ordered by the agency
- Design changes that alter scope or sequence
- Site conditions differing from those foreseen
- Force majeure
- Non-payment affecting execution
What does not support an extension: lack of your own resources, productivity below plan, poor planning, subcontractors who fail to perform. Those are the contractor’s risks.
The requirement almost nobody meets properly
Each cause needs three things proven, not one.
That it happened. The fact, with date, location and an objective description.
That it is not attributable to you. That the cause lies outside your sphere of control.
That it hit the critical path. This is the one that gets forgotten and the one that decides.
On the third it pays to be explicit: a delay in an activity with float does not generate a time extension. If the front that was not released to you belonged to an activity with fifteen days of float and the delay ran ten, there was no effect on the completion date. The agency will review it in exactly those terms.
That is why the backup is not just evidence of the fact: it is the schedule analysis that demonstrates the effect. You need the schedule before, the schedule after, and the explanation of how the fact moved the critical path.
The backup, in order of strength
| Element | What it proves |
|---|---|
| Contemporaneous bitácora entry | That the fact happened, on that date |
| Letter with acknowledgment of receipt | That the agency was notified in time |
| Dated photograph with location | Visual evidence of the state of the front |
| Daily report with idle crew | The effect measured in resources |
| Schedule before and after | The effect on the critical path |
| Signed meeting minutes | Acknowledgment by the other party |
The bitácora is the central piece, for a reason that goes beyond its content: it is the instrument both parties recognise as the means of communication. A fact recorded there at the time, with no objection from the other side, is hard to deny later.
The sequencing mistake
This is the pattern that repeats and that costs most of the extensions that are lost.
The project falls behind for external causes. The site engineer knows it, the supervisor knows it, everybody talks about it. Nobody records anything, because the relationship is going well and documenting feels like distrust. Work carries on. Three months later the project is not going to finish on time, liquidated damages appear on the horizon, and that is when the reconstruction begins.
By then: the fronts have been released and there is no photo of how they were, the instructions were verbal and nobody recorded them, the idle crew was never logged, and the schedule was never updated. Everybody remembers the same thing and nobody can prove it.
The solution is routine and boring: record every event the same day, with its effect measured, even when at that moment it looks like it will never be needed. Most of those entries are never used. The ones that are used pay for all the rest.
The process
While the specific deadlines depend on the contract and the applicable rules, the general sequence is:
- Record the fact in the bitácora, the same day
- Formal notification to the agency within the prescribed period
- Request for the extension with the backup assembled
- Review by the resident engineer’s office and the agency
- Determination and, where it applies, a modifying convenio
Article 59 of the LOPSRM governs the agreements that modify contracts, including their limits and conditions. It is worth reading before you negotiate, because there are restrictions on amounts and on what may be modified.
And a cash-flow note that tends to surprise: agreements entered into under article 59 do not receive an advance payment, except in the cases the law itself sets out. If your extension involves significant additional work, you finance that part without an advance.
Frequently asked questions
- Can I request an extension after the deadline has passed?
- It is a much weaker position. Contracts and regulations set deadlines to notify and to request; once they pass, the right becomes complicated even if the fact is true. Timely notification is what preserves the right, even before you have the quantification.
- Does a time extension automatically mean costs are recognised?
- No. They are different things. The extension moves the date; the unrecoverable costs arising from that extension — field overheads over the additional period, for instance — have their own treatment and their own backup.
- What if the agency denies the extension?
- There are objection and conciliation routes provided for in the regulations. What decides any of them is the file you built during the project: if it is solid, the formal route makes sense; if it is not, it rarely changes the outcome.
- Do signed meeting minutes work as backup?
- They do, especially if signed by both parties and reflecting acknowledgment of the fact. They replace neither the bitácora nor formal notification, but they strengthen the whole.
- Should I keep working while it is resolved?
- Normally yes, unless suspension is expressly instructed. Carrying on does not waive the right if you left a timely record of the fact and of the reservation. That is precisely why the contemporaneous record is so decisive.
Founder and CEO of Paladio. He has spent more than 15 years building financial products that touch the lives of millions of people. He writes about what he sees on site: how progress is really measured and where the money leaks.
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