Even the smallest oversight in a contract can lead to major disputes, delayed payments, or costly litigation. As any seasoned construction law attorney will tell you, clearly written and thoroughly reviewed contracts are the backbone of successful projects.
Unfortunately, many contractors, subcontractors, and property owners rely on handshake deals or poorly written agreements, leaving them exposed to unnecessary risk. Whether you’re building a custom home, remodeling a commercial space, or managing large-scale developments, avoiding common contract mistakes can save you time, money, and legal headaches down the road.
Below, we highlight some of the most frequent construction contract pitfalls and how a construction law attorney can help you steer clear of them.
1. Not Getting the Contract in Writing
This is, hands down, the biggest mistake in construction.
Verbal agreements are incredibly difficult to enforce. Memories fade, terms get misunderstood, and when something goes wrong, it often becomes a he-said, she-said situation. A written contract creates a legally binding record of expectations and obligations.
Example: A contractor agrees to remodel a client’s kitchen for “about $30,000,” promising to “start next month.” No written agreement. When delays happen and costs spiral to $42,000, the client refuses to pay. Without a signed contract, resolving the dispute becomes messy and expensive.
Avoid it: Always get your construction contract in writing, even if it’s a small job. Work with a construction law attorney to ensure the document is legally enforceable and covers all key details.
Note: In California, it is mandatory to have a contract in writing any time a contractor is performing a “work of home improvement.” A work of home improvement contract must comply with numerous requirements of the Business and Professions Code in California to be valid.
A “work of home improvement” encompasses activities such as repairing, remodeling, altering, converting, modernizing, or adding to residential property. It also includes the installation of home improvement goods or the furnishing of home improvement services.
Specific examples of home improvement include the construction, erection, installation, replacement, or improvement of driveways, swimming pools (including spas and hot tubs), terraces, patios, awnings, storm windows, solar energy systems, landscaping, fences, porches, garages, fallout shelters, basements, and other improvements to structures or land adjacent to a dwelling house and/or the installation of home improvement goods or the furnishing of home improvement services.
These goods and services are defined as those bought in connection with the improvement of real property, such as carpeting, texture coating, fencing, air conditioning or heating equipment, and termite extermination. Goods that are affixed to real property and become part of it, whether severable or not, are also included in the definition. Cal Bus & Prof Code § 7151.
It also includes landscaping activities like seeding, sodding, or planting, as well as site preparation activities such as filling, leveling, or grading of real property. Cal Civ Code § 8050.
2. Vague or Missing Scope of Work
A common cause of conflict is a scope of work that’s incomplete or unclear.
Without a clearly defined scope, disagreements are inevitable. What’s included? What’s not? Who’s responsible for permits, cleanup, or material sourcing?
Example: A homeowner hires a builder to renovate their bathroom. The contract just says “Bathroom remodel: $15,000.” No mention of demo work, plumbing rerouting, or tile selection. Later, the homeowner insists that all tile should be marble. The builder assumed ceramic. Now there’s a standoff.
Avoid it: Spell out the scope of work in detail. List materials, finishes, tasks, and any exclusions. Better yet, include diagrams or plans.
For guidance on how to write clear and enforceable construction contracts, check out our guide here.
3. Not Including a Payment Schedule
A well-structured payment schedule is essential for cash flow and managing expectations. Without it, you risk non-payment, delayed funding, or work stoppages.
Example: A contractor completes 70% of a home addition but receives only a 30% deposit. The client drags their feet on making the next payment, claiming they’re “waiting to see the final product.” The contractor has no leverage or timeline to enforce payment and ends up in court.
Avoid it: Break down payments into stages tied to specific milestones, such as deposit, framing completion, drywall installation, or final inspection. Include due dates, acceptable payment methods, and penalties for late payment.
4. Skipping Essential Legal Provisions
Many construction contracts leave out key clauses that would otherwise provide clarity and legal protection. These include:
- Change order procedures: What happens if the client wants to add a patio mid-project?
- Dispute resolution methods: Will issues go to mediation, arbitration, or court?
- Termination clauses: What happens if either party wants out?
Example: A subcontractor walks off the job halfway through due to lack of payment. There’s no clause explaining what happens next, and the GC is left scrambling and vulnerable to a lawsuit from the property owner.
Avoid it: Include these provisions from the start. A construction law attorney can help you build a standard contract template with these built in, saving you from legal scrambling later.
5. Failing to Comply with Local Laws and Licensing Requirements
Construction laws vary by state and city. Using a generic template found online can lead to non-compliance with local regulations or building codes, which may void parts of the contract.
Example: A contractor in California uses a contract template from an East Coast company. It doesn’t include required consumer notices, fails to reference local lien laws, and doesn’t meet state licensing disclosure rules for a work of home improvement with a homeowner. The client uses this to challenge payment in court—and wins.
Avoid it: Have your contracts reviewed by a construction law attorney familiar with your jurisdiction. This ensures compliance with state-specific licensing, lien rights, and consumer protection statutes.
Preventing Mistakes Starts with Legal Support
Poorly written or incomplete contracts are one of the leading causes of legal disputes in construction. But most of these issues are preventable with proper planning and legal guidance.
Whether you’re a contractor, builder, investor, or homeowner, working with a qualified construction law attorney can make all the difference. They’ll help you draft, review, and negotiate contracts that are clear, fair, and legally enforceable.
Need help with your construction contracts? Our team at The Mellor Law Firm specializes in business and construction law. We help clients across California build contracts that stand up in court and keep projects on track. Get in touch if you’d like a second set of eyes on your contracts!