Short answer. No, not on that basis alone. Article 1724 of the Civil Code says a contractor building for a stipulated price cannot withdraw or demand an increase for higher labor or material costs, unless the plans changed with the owner's written authorization and both parties fixed the additional price in writing.
What the law says
can neither withdraw from the contract nor demand an increase in the price on account of the higher cost of labor or materials, save when there has been a change in the plans and specifications
Civil Code, Article 1724 — No Price Increase Without Written Consent. Read the full provision →
The stipulated price is meant to hold
Article 1724 provides that a contractor building for a stipulated price, in conformity with plans and specifications agreed upon with the land-owner, can neither withdraw from the contract nor demand an increase in the price on account of the higher cost of labor or materials. Once you and the contractor have agreed on a fixed price for a defined scope of work, rising material costs are, as a rule, the contractor's risk to absorb, not yours to cover.
The narrow exception, and its two requirements
The article allows an increase only when there has been a change in the plans and specifications, and even then only if two conditions are both met: the change has been authorized by the proprietor in writing, and the additional price has been determined in writing by both parties. A verbal request for more money because materials cost more, with the original plans unchanged, does not fit within this exception at all.
Why the writing requirement matters
Both conditions have to be documented in writing — your authorization for the changed plans, and the parties' written agreement on the extra amount. A contractor cannot rely on an oral understanding, a text message alone, or an implied consent from your silence to justify billing more. If either writing is missing, the contractor's demand for an increase falls outside what Article 1724 permits, regardless of how the material costs actually moved.
What to do if you get such a demand
Check your contract for the original plans and specifications, and ask what specific change the contractor is pointing to. If no plan change occurred, or if you never signed a written authorization and price agreement for one, you have a strong basis to resist the increase. Keep all correspondence about the demand and bring the contract to a lawyer if the contractor persists or threatens to stop work.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Licomcen, Inc. vs. Engr. Salvador Abainza, etc, G.R. No. 199781, February 18, 2013 — read the decision on LawPhil →
- Spouses Victoriano chung and Debbie Chung vs. Ulanday Construction, Inc, G.R. No. 156038, October 11, 2010 — read the decision on LawPhil →
- Leighton Contractors Philippines, Inc. vs. CNP Industries, Inc, G.R. No. 160972, March 9, 2010 — read the decision on LawPhil →
- Powton Conglomerate, Inc., et al. vs. Johnny Agcolicol, G.R. No. 150978, April 3, 2003 — read the decision on LawPhil →