Historic Window Restoration and Change Orders: How to Reduce Surprises
Why the Best Historic Restoration Projects Aren't the Ones Without Change Orders—They're the Ones That Manage Them Well
Few phrases create more tension on a construction project than "change order."
Owners worry about budgets. General contractors worry about schedules. Architects worry about scope. Subcontractors worry about documenting conditions that no one could have reasonably anticipated.
On historic rehabilitation projects, these concerns are amplified because the building itself often reveals new information only after work begins. Unlike new construction, historic restoration rarely starts with perfect information. Layers of paint conceal repairs made decades earlier. Moisture damage may not become visible until glazing is removed. Steel corrosion can hide beneath coatings that appear intact.
That reality doesn't mean change orders are inevitable—or that they should be expected on every project. It does mean that the most successful historic restoration projects are those that reduce uncertainty before construction and communicate effectively when genuine unforeseen conditions arise.
The objective isn't to eliminate every change order. The objective is to eliminate the unnecessary ones.
Historic Buildings Don't Read the Drawings
Construction documents represent the best understanding of a building at a particular point in time. Historic buildings, however, often contain conditions that no drawing can fully capture.
A window scheduled as "repair" may reveal:
concealed structural deterioration
extensive previous modifications
insect damage
deteriorated glazing rabbets
failed Dutchman repairs
hidden steel corrosion
moisture damage beneath paint
None of these conditions may have been visible during a visual survey. That isn't a failure of the architect or consultant. It's simply the nature of working with buildings that may have stood for more than a century.
Recognizing this reality early helps establish realistic expectations for everyone involved.
Not Every Discovery Should Become a Change Order
One of the biggest misconceptions surrounding historic restoration is that every unexpected condition justifies additional cost.
It doesn't.
Experienced restoration contractors typically anticipate a reasonable amount of routine deterioration within the original scope.
Examples might include:
localized glazing repairs
minor wood repairs
replacing broken sash cords
adjusting hardware
isolated paint failure
These are common restoration activities. They should generally be expected. The conversation changes when conditions exceed what could reasonably have been anticipated during preconstruction.
Examples include:
extensive concealed rot
structural failure
widespread insect damage
missing components
significant previous alterations
major steel section loss
Those conditions often require additional evaluation and, in some cases, additional scope. The distinction is important.
The Best Change Orders Begin Long Before Construction
Ironically, many successful change orders begin during preconstruction.
How? By documenting assumptions.
Well-prepared proposals frequently identify:
anticipated repair limits
excluded conditions
replication thresholds
access assumptions
glazing assumptions
finish expectations
This isn't about protecting one party at the expense of another. It's about creating transparency. When assumptions are clearly documented, later discoveries become easier to evaluate objectively.
Condition Assessments Reduce Surprises
One of the best investments a project team can make is a thorough condition assessment before pricing is finalized.
Representative investigations often reveal:
recurring deterioration patterns
previous repair methods
moisture issues
hardware conditions
glazing failure rates
The more representative information collected during preconstruction, the fewer surprises tend to emerge during production. No assessment eliminates all uncertainty. But good assessments dramatically reduce it.
Mockups Are More Than Quality Control
We've discussed mockups previously as a quality assurance tool. They're also an excellent risk management tool.
Mockups help identify:
repair feasibility
hidden deterioration
restoration methodology
production rates
owner expectations
Sometimes a mockup reveals that restoration will be more straightforward than expected. Other times, it uncovers conditions that justify revisiting the budget before full production begins. Both outcomes benefit the project.
Define Restoration Thresholds Early
One area where change orders frequently originate is the transition between restoration and replication.
Imagine a specification that simply states:
"Restore existing windows."
What happens when one sash proves impossible to restore? Without predefined criteria, every difficult window becomes a discussion. Instead, project teams should establish objective thresholds during preconstruction.
Examples might include:
percentage of material loss
structural integrity
repair feasibility
preservation requirements
operational safety
When everyone understands those thresholds in advance, field decisions become more consistent.
Documentation Matters
Historic restoration is one of the most document-intensive construction scopes. Good documentation protects everyone.
When unexpected conditions arise, contractors should provide:
photographs before intervention
written condition descriptions
proposed repair options
schedule implications
cost impacts
preservation considerations
This allows architects and owners to make informed decisions based on evidence rather than assumptions. Clear documentation often prevents disagreements before they begin.
Communication Is the Best Risk Management Tool
Perhaps the most effective way to reduce contentious change orders is simple: Communicate early.
Don't wait until twenty windows have been opened before raising concerns. If a recurring condition appears, involve the project team immediately.
Historic restoration succeeds when information flows quickly between:
owners
architects
preservation consultants
general contractors
restoration specialists
Early communication creates options. Late communication creates urgency.
Understand the Difference Between Unknown and Unknowable
This distinction is worth making. Some conditions are unknown because they were not investigated. Others are unknowable without dismantling historic fabric.
Those are not the same.
Historic preservation often discourages unnecessary demolition during investigation. As a result, some conditions simply cannot be confirmed until restoration begins. Recognizing that limitation helps everyone approach discoveries more reasonably.
Unit Pricing Can Simplify Decision-Making
On larger projects, predetermined unit prices can reduce administrative delays.
Examples might include:
additional glazing per lite
rail replacement
stile replacement
Dutchman repairs
hardware replacement
replicated sash
steel section repair
Rather than negotiating every occurrence individually, project teams can agree on pricing mechanisms in advance. This keeps production moving while maintaining cost transparency.
Change Orders Should Solve Problems, Not Create Conflict
The purpose of a change order is often misunderstood. A well-managed change order is not a sign that the project failed. It is simply the contractual mechanism used to address work outside the original agreement.
The best historic projects treat change orders as collaborative problem-solving tools. Not adversarial negotiations. That mindset benefits everyone.
Early Collaboration Reduces Late Surprises
Many avoidable change orders stem from assumptions made in isolation.
Projects tend to perform better when restoration specialists are involved during:
design development
budgeting
mockups
specification review
constructability discussions
Early collaboration often reveals issues before they become field problems. That saves time, protects budgets, and improves relationships across the project team.
Final Thoughts
Historic rehabilitation projects are built on discovery. Every building contains a story that only becomes fully visible as restoration progresses.
The goal is not to eliminate every unknown. It is to reduce uncertainty through thoughtful planning, clear communication, and realistic expectations.
When project teams invest in condition assessments, mockups, documentation, and collaboration, change orders become less frequent—and far less disruptive. Ultimately, the most successful historic restoration projects are not those where nothing unexpected happens. They are the ones where the unexpected is handled professionally, transparently, and with the shared objective of delivering the best possible outcome for the building.
(Image by Magnific)
