Note
How to Update a Maintenance Agreement When the Site Changes
A maintenance agreement is written around the installation that exists at signing. Over the life of a two or three-year agreement, additions, upgrades, and expansions change what is actually on site.
Most contractors respond by covering the new work without updating the agreement. That usually holds until something fails in the new equipment and both sides argue about coverage based on documents that describe a different installation.
Why Does Maintenance Scope Drift?
A factory’s electrical installation is not static. Common triggers for scope change during an active maintenance agreement include:
- System expansion. A factory adds a second phase to an existing rooftop solar installation, or extends an LED retrofit into a production area not included in the original scope.
- Equipment replacement. A failed inverter or distribution panel is replaced with a newer model. The replacement is covered by location but may require different service intervals or firmware procedures not in the original specification.
- New facility areas. The factory builds a new warehouse or extends a production line. The new space gets its own electrical installation and the client assumes the existing maintenance contractor covers it automatically.
- Scope reassignment. The factory’s in-house team takes on tasks that were in your scope (panel cleaning, for example), or they ask you to take on tasks they were handling themselves.
In each case, the contractor is either doing more than was agreed for no additional fee, or the client believes more is covered than the contract says.
What Actually Counts as a Scope Change?
Not every variation needs a formal amendment. The question is whether the change creates additional labor or materials obligations beyond what the original fee covers.
Clearly in scope: anything named explicitly in the original agreement, unchanged since signing.
Clearly outside scope: new equipment added after signing that was not present at the original survey.
The grey zone: replacement equipment of the same type in the same location. A failed inverter replaced with a newer model of the same capacity is still the same location and roughly the same task. But newer firmware procedures, different connector types, or an updated service schedule from the manufacturer may add time that was not in the original estimate. Worth noting in writing even when the additional work is small.
The practical test: does covering the new equipment require additional technician-days in any year of the agreement? If yes, it warrants an amendment.
How Do You Handle a Mid-Contract Scope Change?
When a scope change is identified, the process has four steps:
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Survey before pricing. Visit the new equipment or area using the same brief you would use for a pre-maintenance survey on a new site: what is the system, what are the tasks, and what access does it need?
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Draft an amendment. Write a short addendum describing the new equipment, the tasks added, the visit schedule, and the additional annual fee. A new contract is not required.
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Agree before starting the work. This is the step most contractors skip. The amendment conversation must happen before the first visit that covers the new equipment. Once you have done the work without an amendment, the expectation is set and difficult to change.
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Update the site record. Record when the new equipment was added, what was surveyed, and what the amendment covers. This is the document that answers “what is actually maintained under this agreement?” a year from now.
Worked example: a contractor holds a maintenance agreement for a 350kWp solar installation in Samut Prakan. In year two, the factory adds a 120kWp second array on a different roof section. The contractor surveys the addition in August, estimates three additional technician-days per year, gets the amendment signed before the October visit, and updates the site record to show the full 470kWp installation. When the November annual inspection covers the new array, there is no ambiguity about whether it is within scope.
What If the Factory Expects Coverage Without an Amendment?
This conversation is common. The facilities team adds a new distribution board or expands an LED zone, assumes the maintenance contractor covers it, and the first indication is a question about whether the new equipment was checked at the last scheduled visit.
The most effective response is factual rather than contractual: “The current scope covers [the specific installation at signing]. The new equipment was not in the original survey. Let me assess it and come back with what adding it properly would take.”
Avoid leading with “that is not in the contract.” It is accurate but creates friction. The facilities team raising the question typically did not negotiate the original agreement.
What matters after the conversation is the record. Send a brief follow-up message: the new equipment was identified, it is outside the current scope, a survey is planned for a specific date. That message documents the situation regardless of what happens next.
What the Site Record Has to Show
A maintenance agreement running for two years typically covers a site that has changed since signing. If the site record still reflects the original installation, it is no longer accurate.
After any scope amendment, update the site record with the current equipment list, photographs, and the amendment date. If the factory made changes without informing you and you discovered them at a scheduled visit, record the finding as an observation: what was found, the date, and a note that it falls outside the current scope. The record does not resolve coverage. It makes both questions answerable with evidence: what is on site, and what the agreement says.
FAQ
Does a verbal agreement to cover new equipment create an obligation?
A verbal agreement creates an expectation. The practical protection is to confirm what was discussed in writing before starting any additional work. A brief message by LINE or email summarizing the conversation gives both parties a record and prevents the common outcome where both sides remember the agreement differently.
How should a scope amendment be priced?
Use the same method as the original agreement: count the additional technician-days the new scope requires in a year, apply your fully loaded daily cost, and add your target margin. An amendment priced by feel carries the same risk as a contract priced by feel. It is a recurring obligation, not a one-off job.
Can scope be removed from a running agreement?
Yes, using the same process. Survey what is being removed, confirm the client’s agreement in writing, and issue an amendment that reduces the scope and adjusts the fee. The reason to formalize a reduction: if a fault occurs in the removed scope after the amendment date, the record is clear about whose responsibility it is.
If your site records still describe the original installation rather than what is on site today, that gap is worth closing before the next scheduled visit. The TRACE 30 program builds a site register from closed job records and updates it each time work is done, so the record stays current as an installation changes over time. Schedule a call if you want to see how the site register handles an installation that has grown since handover.