Choosing a custom home builder is a massive decision, but many homeowners don’t realize that the type of contract they sign is just as critical as the builder they hire. The contract dictates your visibility into costs, how your budget is managed, and ultimately, how your interests are protected during the year-long journey.

In the Raleigh-Durham area, you’ll typically encounter three ways contracts are structured. Here is a breakdown of how they work in the real world.

1. The Fixed Price Contract: The Illusion of Certainty

A fixed price contract sounds simple: a builder says they will build your house for a set dollar figure. It feels safe, but in today’s market, it is often an illusion.

• The Allowance Trap: These contracts are built on allowances, estimates for things like tile, appliances, and lighting.  This means you have to become the expert and know if the allowances given will work for you.  Additionally, if prices increase from contract signing to purchasing, your allowance bucket just shrunk.
• Shifting Risk: With the volatility of material prices, many builders now move categories that were traditionally not allowanced (for example framing and siding materials) into allowance items with a defined max cost. That means if prices spike, that fixed number isn’t so fixed anymore, and the risk may transfer right back to you, depending on what you and your builder agreed to.
• The Conflict of Interest: Fixed price builds can be tough to navigate because the builder is incentivized to come in at or below the bid amount.  This may lead clients to question decisions that are being made by the builder, even if those decisions are perfectly logical and in the clients’ best interest.  But every dollar saved by the builder is a dollar earned in a fixed price contract.

2. Cost-Plus Percentage: The Ticking Clock

This is the most common model in custom building. You pay the cost of the project, plus an agreed to percentage amount that is added to the costs.  This offers transparency on costs for the client and full margin protection for the builder.

• The Foot in the Door Risk: A builder might underestimate the total cost just to win the job, knowing their fee will grow as the project inevitably hits the real numbers later.
• Profit Motivation: Because the fee is a percentage, the builder makes more money if you spend more. Additionally, depending on the arrangement you negotiate, you could be on the hook for paying the builder fee on things that no one saw coming.  For example, if lumber prices suddenly spike by 10% right before your builder orders the material, you may be paying a percentage increase to your builder for that as well.  No fault of anyone, but an example of a sleeping bear.  Additionally, a builder who is compensated on a percentage may have a more difficult time giving what he or she knows is good advice when that advice comes at a higher cost than what was budgeted.  You don’t want to be wondering if advice has a profit motive behind it.
• Performance vs. Time: The builder is typically paid on every monthly invoice. Their compensation is tied to the ticking of the clock, not necessarily to hitting major milestones.

3. The Fixed Fee Hybrid: Cost-Plus a Fixed Fee

At Grau Building Company, we take a different approach. Instead of a percentage-based fee that fluctuates, we use a Cost-Plus Fixed Fee model. This structure is designed to give you the transparency and flexibility of cost plus model while assigning our compensation to a fixed dollar amount.  You know what you pay us up front.

To make this work, our process is broken into two distinct stages:

Stage 1: The Letter of Engagement (The Planning Phase)

The Letter of Engagement (LOE) isn’t just a document you sign; it outlines a dedicated period of time, typically 3 to 12 months, where we work side-by-side with you and your architect before construction even begins.

• Working Off the Deposit: You provide a nominal deposit, and we work off that deposit money as we refine the plans and nail down the scope of work. We are actively using this time to build a budget that reflects the reality of your vision and that takes a meaningful amount of time and effort.
• The Homework Period: This is when we help you get out into the real world to make selections on appliances, countertops, and tile.  There’s no better time to make selections than before you start.  We’ve seen how well it works and while it can feel like swallowing the ocean at times, you’ll be in such a better position when it comes time to start.
• Confidence in the Calendar: We use this time to see how much of the project is figured out. For example, if you finish your homework and have 80% of the project nailed down during the LOE, we can reward that with a more competitive fixed fee because we have 80% confidence we can hit our schedule.

New to the process? Read our guide on hiring a custom builder and navigating those first estimate meetings.

Stage 2: The Construction Agreement (The Execution Phase)

Once the planning is done, we move into the formal construction agreement. Because we’ve used the LOE phase to pull back the curtain on the unknowns, the build is smoother and faster.

• Milestone-Based Payments: Our fixed fee isn’t taken as the clock ticks; it’s paid out when we hit specific milestones on the job site. If we aren’t performing, we aren’t getting paid.
• Zero Profit Motivation: Since our fee is a set dollar amount agreed upon at the start, it stays the same regardless of minor  adjustments. We don’t make more money if you choose a more expensive range or decide to expand your closet by a foot or two.  Find a builder who does that!
• Mutual Collaboration: We can talk openly about money in real-time because our profit isn’t baked into your material costs. Clients see what we see, and there is no filter.  That allows you to have meaningful conversations with our trade partners too, as the conversation does not have to pause as money is discussed.  Whatever the cost is, the cost is.

Our LOE is more than a contract, it’s how we ensure the best possible outcome for your home. Learn more about how we define success.

The Power of Organization: 203 Working Days

The LOE period is the foundation, but our organization is what gets you moved in. We recently completed a modern build, a style that requires visual perfection in just 203 working days.

This efficiency is possible because we are power users of a project management system called CoConstruct. While some builders use software just for photos or a high level calendar, we use it for everything: budgets, schedules, job logs, invoicing, and trade communication. For a client out of Houston who only visited their site four times during the entire build, this system provided the daily logs and photos they needed to feel like they were standing on the job site every day.

Building the Right Team

A successful build isn’t just about the builder; it’s about the integration of the whole team. We stress the importance of involving an interior designer, like the team at Grau Design Studio, landscape architects and civil engineers early in the pre-construction phase.

Having your designer plugged into the same project management system as your builder means that when a decision needs to be made about the color of the hinges or the exact placement of a floor outlet, the information is already there. This proactive communication is what prevents decision fatigue and keeps the trades from standing around because they’re waiting on a choice to be made.

The Conclusion: Clients for Life

At GBC, we don’t really say goodbye when the house is done. We end with a celebration, but we stay as a resource for years. We don’t like our clients “dating” other builders, so whether it’s a minor repair or hanging a Christmas wreath, we want to be your first call.

In the end, it’s about fairness. We’ve built our business model to be transparent because it’s the most comfortable way to do business, for us and for you.

Questions to Ask Your Builder

1. How does your fee change if my material costs (like lumber) increase by 10%?
2. Is your fee taken as a monthly percentage or tied to project milestones?
3. Will I have real-time access to the budget and schedule through a management system?
4. How do you handle allowance categories in a fixed-price model?