For many homeowners, starting a construction project feels exciting  –  but it can also be overwhelming. Between permits, budgets, and design choices, even the smallest misstep can cost thousands of dollars and months of delays.

The truth? 90% of construction projects go over budget or off-schedule. But it doesn’t have to be that way.

At Berg Development, we’ve worked with California homeowners long enough to recognize the most common mistakes people make. Better yet, we’ve built a system to help you avoid them altogether.

In this guide, we’ll cover:

• The most frequent (and costly) mistakes homeowners make 
• Real-world examples of how these mistakes play out 
• Berg’s proven strategies for keeping projects on track 
• Why working with a design-build partner changes everything 

Mistake #1 – Starting without a clear budget

Many homeowners jump into construction with a “ballpark” number in mind, but without a detailed financial plan.

What happens:

• Unexpected costs pile up (permits, materials, labor increases). 
• Scope creep  –  adding features mid-project without adjusting budget. 
• Financial stress or even incomplete builds. 

Berg solution: We start with transparent estimates that factor in permits, materials, labor, and contingencies. No guesswork, no surprises.

Mistake #2 – Underestimating timelines

TV shows make construction look quick  –  but real life is different. Homeowners often expect a 2-month ADU build when it might realistically take 4 – 6 months.

What happens:

• Frustration when deadlines slip. 
• Poor coordination with rental moves or financing schedules. 
• Cutting corners to “speed things up.” 

Berg solution: Our timeline planning process includes permitting realities, inspections, and supply chain delays. We communicate clear milestones upfront and adjust proactively when needed.

Mistake #3 – Skipping the design phase

Some homeowners rush straight into construction, thinking it saves money. In reality, poor planning creates costly mistakes later.

What happens:

• Rooms that don’t flow well. 
• Light placement that feels wrong once walls are up. 
• Redoing work (tearing down walls, moving plumbing). 

Berg solution: We follow a design-led process with 3D modeling and walkthroughs before construction begins. This minimizes guesswork and ensures the final product matches your vision.

Mistake #4 – Choosing the cheapest contractor

It’s tempting to choose the lowest bid  –  but in construction, you often get what you pay for.

What happens:

• Hidden costs surface mid-project. 
• Inferior materials or shortcuts in workmanship. 
• Warranty issues or lack of accountability after the project ends. 

Berg solution: We’re not the cheapest, and that’s intentional. We focus on quality, transparency, and long-term value  –  backed by warranties and ongoing client support.

Mistake #5 – Ignoring permits and legal requirements

California has strict building codes, especially for ADUs and energy efficiency (Title 24). Some homeowners skip or delay permits, hoping to save time or money.

What happens:

• Fines and stop-work orders. 
• Difficulty refinancing or selling the home. 
• Safety risks from uninspected work. 

Berg solution: We handle the entire permitting process, ensuring your project is 100% compliant with California regulations.

Mistake #6 – Forgetting about long-term costs

A shiny new kitchen or ADU might look great  –  but what about maintenance, energy costs, and ROI over time?

What happens:

• High utility bills due to poor insulation or inefficient HVAC. 
• Quick material wear leading to costly repairs. 
• Missed opportunities for rental income or resale value. 

Berg solution: We design with sustainability and ROI in mind  –  recommending energy-efficient upgrades, durable materials, and layouts that add long-term value.

Mistake #7 – Not communicating with the builder

Construction is a partnership. When homeowners check out of the process, things get missed.

What happens:

• Misunderstandings about finishes, layouts, or budgets. 
• Frustration when expectations aren’t met. 
• Costly rework. 

Berg solution: We pride ourselves on constant communication. Clients have regular updates, milestone meetings, and full transparency on progress.

Why a design-build approach avoids these mistakes

Traditional construction often separates design and build into different companies. This creates gaps where mistakes thrive.

Berg’s design-build approach means:

• One team handles everything  –  from design to permits to construction. 
• Budgets and timelines are coordinated from day one. 
• Communication is streamlined, reducing errors and delays. 

It’s not just about building structures. It’s about building trust, clarity, and efficiency.

Conclusion

Homeowners don’t set out to make mistakes in construction  –  but without the right guidance, it’s easy to fall into traps that cost time, money, and peace of mind.

At Berg Development, we’ve built a system that helps clients avoid these pitfalls, ensuring every project runs smoothly from dirt to design.

📞 Ready to build without the stress? Contact Berg Development today for your free consultation.