The Real Cost of Design Changes During Construction
“Can we just move this wall?”“Can we make the kitchen bigger?”“I changed my mind about the tiles.”
These may sound like simple requests during construction. But once workers are already on site, even a small design change can affect much more than the item being changed.
For homeowners building or renovating a house in the Philippines, understanding this is important. A change made during construction can add materials and labor costs, cause delays, create additional professional fees, and sometimes require previously completed work to be redone.
The real cost of a design change is therefore not always the price of the new material or the additional work.
It is the chain reaction that the change can create.
Why Design Changes Become More Expensive During Construction
During the design stage, changing a wall, window, electrical outlet, or room layout may simply mean revising a drawing.
During construction, that same change can involve several people and several trades.
For example, imagine that you decide to move a bedroom door after the wall has already been constructed.
The change may involve:
dismantling part of the existing wall;
additional masonry or drywall work;
relocating electrical wiring;
modifying switches or outlets;
adjusting ceiling or lighting locations;
repainting affected areas;
purchasing additional materials;
paying additional labor;
revising drawings or construction instructions; and
potentially affecting the construction schedule.
What looked like a ₱5,000–₱10,000 decision can therefore become a much larger project adjustment.
This is why construction changes should be evaluated based on their total impact, not simply the visible cost of the new item.
The Five Costs Behind a “Small” Change
A useful way to understand construction changes is to look at the different layers of cost they can create.
1. The Direct Cost
This is the most obvious cost.
You may want to upgrade:
floor tiles;
bathroom fixtures;
doors;
windows;
countertops;
cabinets;
lighting fixtures; or
other finishes.
The additional material itself may cost more.
For example:
Original tile: ₱800/m²New tile: ₱1,200/m²Difference: ₱400/m²
If the affected area is 30 m², the material difference is approximately ₱12,000.
But that may only be the beginning.
2. The Removal and Rework Cost
If construction has already progressed, something may have to be removed before the new work can begin.
This is where a relatively inexpensive design change can become costly.
Consider changing a bathroom floor tile after installation.
You may now have to pay for:
Remove → Dispose → Prepare → Reinstall → Finish
The owner is effectively paying for part of the work twice.
The same principle applies to walls, ceilings, cabinetry, plumbing, electrical installations and other completed work.
The earlier you make the change, the cheaper it usually is.
A change made while the project is still on paper is fundamentally different from a change made after the work has already been built.
3. The Impact on Other Trades
Construction is interconnected.
One decision can affect several trades.
For example, moving a kitchen sink may require changes to:
Cabinetry → Plumbing → Countertop → Electrical → Wall finishes
Moving an air-conditioning unit may affect:
Electrical → Drainage → Ceiling → Wall opening → Exterior appearance
Moving a window may affect:
Masonry → Waterproofing → Electrical → Curtains → Interior finishes → Exterior finishes
This is why an architect or contractor should evaluate the knock-on effects of a proposed change before work proceeds.
A change should not be priced based only on the item that the homeowner wants to modify.
4. The Cost of Delay
Time is another cost that homeowners sometimes overlook.
A change may require:
a revised drawing;
a contractor's quotation;
owner approval;
material ordering;
delivery;
coordination with subcontractors; and
additional construction work.
If the new material is not immediately available, the affected work may have to stop or be resequenced.
That can create additional project costs.
For example, a special-order tile may take several weeks to arrive. While waiting, the contractor may have to move workers to another area of the project.
In some cases, this can affect the overall completion date.
For homeowners renting another property while waiting for their new house, even a few additional weeks can have a real financial impact.
5. The Professional and Administrative Cost
A design change can also require professional work.
Depending on the change, the architect or other consultants may need to:
revise drawings;
prepare additional details;
coordinate with the contractor;
review alternatives;
check structural implications;
coordinate electrical or plumbing changes;
update specifications;
review the contractor's quotation; and
document the approved change.
This work takes time.
A properly managed construction change should therefore be treated as a project decision—not simply as an informal instruction given at the job site.
Professional construction contracts commonly use written change-order procedures precisely because changes can affect both contract price and construction time.
A Simple Example: Moving a Wall
Let's say a homeowner decides to make the living room larger by moving a partition wall by one meter.
At first glance, the change might appear straightforward.
But consider what could already be affected:
Possible Impact | What May Need to Change |
Wall | Demolition and reconstruction |
Electrical | Outlets, switches and wiring |
Ceiling | Ceiling layout or lighting |
Flooring | Additional flooring or repair |
Paint | Repainting affected areas |
Doors | Door location and swing |
Furniture | Built-in cabinetry or furniture layout |
Air-conditioning | Location of indoor unit or piping |
Construction schedule | Additional work and coordination |
Professional services | Revised drawings and instructions |
The cost of the change is therefore not simply:
“How much does one meter of wall cost?”
It is:
Cost of new work + cost of removing completed work + cost of affected trades + cost of delay + professional/administrative costs
That is the real cost of the decision.
Not All Changes Are Bad
This does not mean that homeowners should never make changes during construction.
Some changes are completely reasonable.
Construction can reveal conditions that were difficult to anticipate during design. Site conditions can differ from expectations, materials can become unavailable, and practical issues can emerge once work begins.
Philippine construction guidance recognizes that certain field conditions and changes may require formal change orders or variations.
The important distinction is between:
Necessary changes
These may result from:
unforeseen site conditions;
material availability;
technical requirements;
coordination issues;
regulatory requirements; or
corrections to actual construction conditions.
Preference-based changes
These happen because the owner simply changes their mind.
Examples include:
“I think I prefer another tile.”
“Can we make this room bigger?”
“Let's move the kitchen.”
“I want a different window.”
“Can we add another bathroom?”
Preference-based changes are not necessarily wrong—but they should be evaluated carefully because the owner is usually paying for their consequences.
Design Changes vs. Design Errors
There is another important distinction.
A homeowner-requested change is different from correcting a genuine design error or omission.
If a properly documented project requires correction because of an error or omission attributable to the design or construction process, the financial responsibility depends on the circumstances, the professional agreement, and the construction contract.
This is one reason why owners should avoid assuming that every additional cost is automatically a homeowner change.
It is worth asking:
Why is this change necessary, and who is responsible for the underlying issue?
Clear documentation helps answer that question.
Philippine public-sector construction guidelines, for example, distinguish between changes arising from contractor errors or omissions and changes resulting from owner-side requirements or other causes. Private residential projects will have their own contractual arrangements, so the specific contract should always be reviewed.
Why “We'll Just Fix It Later” Can Be Expensive
One of the most dangerous phrases in construction is:
“Let's build it first and decide later.”
This approach may feel flexible, but it can create expensive uncertainty.
Suppose you are unsure about the location of:
electrical outlets;
lighting fixtures;
plumbing fixtures;
kitchen cabinets;
bathroom niches;
windows;
doors; or
built-in furniture.
If these decisions are postponed until construction is underway, the project may have to accommodate them through revisions and rework.
Good design is partly about making important decisions before they become expensive decisions.
The Cheapest Time to Change a Design
There is a simple principle homeowners can remember:
The earlier the change, the cheaper it usually is.
Think of the project in stages:
Concept stageChange = relatively easy
↓
Detailed designChange = manageable
↓
Construction documentsChange = possible, but requires revisions
↓
ProcurementChange = may involve cancellation or replacement costs
↓
ConstructionChange = may involve rework
↓
Completed workChange = potentially demolition + replacement
The same design decision can therefore have very different costs depending on when it is made.
How Homeowners Can Control Change Costs
You do not need to eliminate all changes.
Instead, manage them.
1. Finish the design before construction starts
Spend more time making decisions while the project is still on paper.
Review:
floor plans;
furniture layouts;
elevations;
electrical layouts;
lighting;
plumbing;
cabinetry;
doors and windows;
materials; and
key exterior details.
The more complete the design, the fewer expensive surprises you are likely to encounter.
2. Think about how you will actually use the house
Don't choose finishes or layouts simply because they look good in a rendering.
Ask:
Where will furniture go?
Where will appliances go?
Where will storage be needed?
How will doors open?
Where will people walk?
Where will electrical outlets be needed?
Where will maintenance equipment go?
How will the family use the space five or ten years from now?
Good design reduces the temptation to redesign the house while it is being built.
3. Ask for the total cost before approving a change
Don't ask only:
“How much more is this tile?”
Ask:
“What is the total cost and schedule impact of this change?”
A proper evaluation should consider:
Materials + Labor + Demolition/Rework + Other Trades + Professional Services + Schedule Impact
That gives you a much more realistic basis for deciding.
4. Put changes in writing
Avoid relying entirely on verbal instructions.
A properly documented change should identify:
what is changing;
why it is changing;
additional or reduced cost;
effect on construction time;
affected drawings or specifications; and
approval by the appropriate parties.
The Construction Industry Authority of the Philippines notes that written change orders are used to authorize changes or variations in construction work.
Documentation protects both the homeowner and the project team.
Keep a Construction Contingency
Even with excellent planning, construction projects can encounter unexpected conditions.
A reasonable contingency can provide financial breathing room.
However, contingency should not become an excuse for constantly changing the design.
A useful distinction is:
Contingency = money reserved for reasonable unknowns and unforeseen conditions.
Change budget = money intentionally reserved for owner-requested improvements or modifications.
Keeping these concepts separate can make project finances easier to control.
AIA guidance similarly emphasizes that contingency is intended as a risk-management tool and should not simply become a fund for late design decisions.
Before You Approve a Construction Change, Ask These Questions
Before saying “Go ahead,” ask:
Design
What exactly is changing?
Cost
What is the total additional or reduced cost?
Rework
What work already completed will have to be removed or modified?
Coordination
What other trades will be affected?
Schedule
Will this change delay the project?
Materials
Are the new materials readily available?
Professional services
Will drawings or technical documents need to be revised?
Contract
How will the change be formally documented and approved?
These questions can prevent a small decision from becoming a major budget problem.
Good Design Is Also Cost Control
Architecture is often viewed primarily as aesthetics.
But good design is also about planning, coordination and reducing unnecessary decisions during construction.
A well-developed set of drawings and specifications gives the homeowner, architect and contractor a clearer basis for building the project.
It also makes changes easier to evaluate when they genuinely become necessary.
The goal is not to create a project where nothing ever changes.
The goal is to make sure that when something does change, everyone understands:
What is changing.Why it is changing.How much it will cost.What else it will affect.And how it will affect the schedule.
The Bottom Line
A construction change is rarely just a change.
It can trigger a chain of costs:
Design revision → demolition → new materials → additional labor → coordination → rework → delay → additional professional services
That is why the cheapest time to make most design decisions is before construction begins.
For homeowners, the lesson is simple:
Don't ask only, “How much will this change cost?”
Ask:
“What will this change affect?”
That question can save much more money than simply negotiating the price of the new material.
At KDA Design + Architecture, we believe that good architectural planning is not only about creating a beautiful house. It is about helping homeowners make better decisions before those decisions become expensive on-site changes.
The more carefully a project is designed and coordinated before construction, the greater the opportunity to protect the budget, schedule and overall quality of the finished home.
References
Construction Industry Authority of the Philippines (CIAP) — Frequently Asked Questions, including provisions relating to written change orders, changes in work, contract price and contract time.
Department of Public Works and Highways (DPWH) — Department Order No. 111, s. 2021, including supporting documentation and requirements for Variation Orders and proposed design changes.
Department of Public Works and Highways (DPWH) — Revised bidding documents and provisions concerning changes in design, errors, omissions and variation orders.
American Institute of Architects (AIA) Contract Documents — Construction Change Orders: Fundamentals Every Party Should Know, discussing change-order procedures, cost and schedule impacts, documentation and review.
American Institute of Architects (AIA) — A No-Drama Approach to Changes and Change Orders, discussing the nature of construction changes, documentation, client communication and contingency planning.
American Institute of Architects (AIA) — Managing the Contingency Allowance, discussing construction contingencies, unforeseen conditions, design changes and management of change-order costs.
Note: Construction contracts vary. For private residential projects, the actual contract between the owner and contractor should be reviewed to determine how changes, additional costs and schedule adjustments are handled.
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