Because every project is unique, the pathway from initial concept to a fully operational mechanical system varies drastically. For mechanical estimators and MEP firms, choosing the right project delivery is critical to winning profitable work. Among the most common project delivery methods, two stand out: the traditional plan and spec method and the modern design-build approach.
Understanding the differences between design-build vs traditional methods is vital. This guide explores the key differences between design-build and plan-and-spec and how you must adjust your estimating strategy depending on the delivery method to ensure completing a successful project.
The Traditional Route: Plan-and-Spec (Design-Bid-Build)
The plan and spec method, formally known as the design-bid-build approach, has been the standard project delivery system for decades. In design-bid-build construction, the design and construction phases are strictly separated.
First, the project owners hire an architect or engineering firm to complete the project design during the design phase. Once the plan and specifications (the spec) and the final construction documents are 100% complete, the project goes out to bid. A general contractor and various specialized subcontractors submit their pricing to construct the project.
In this design-bid-build project delivery, the owner holds separate contracts for the designer and the builder. For a mechanical estimator, detailed planning is straightforward because you are bidding on a rigid, finalized design. However, if there are design errors or construction delays, finger-pointing between the designer and contractor could delay the project significantly.
The Modern Shift: The Design-Build Approach
Conversely, the design-build model is revolutionizing the construction industry. In a design-build system, you are combining design and construction under one unified umbrella.
A single design-build firm or design-build contractor signs a single contract to execute the entire project. This establishes a single point of responsibility (or a single point of contact) that oversees both design and construction. The design-build method eliminates the traditional silos between the design and the construction phases.
By bringing design and construction under one entity, design-build simplifies the process. It fosters intense collaboration between design and construction experts from day one, ensuring the construction plan is highly feasible.
How Estimating Strategies Change: Design-Build vs. Plan-and-Spec
When evaluating design-build vs the traditional delivery model, a mechanical estimator must radically shift their approach.
Estimating for Plan-and-Spec
In a design-bid-build delivery, the estimator’s job is purely quantitative. You read the finalized plan spec, count the fittings, apply labor units, and submit the bid. There is little room for creativity. You are simply estimating the construction phase based strictly on what the engineer drew.
Estimating for Design-Build
In a design-build project, the estimator is involved long before the drawings are finished. Combining design-build services means estimating often begins during the schematic design phase. You must provide conceptual budgets based on the overall project needs and historical data, rather than exact pipe counts.
Because the design-build process involves early input from the construction team, the estimator acts as a consultant. They use value engineering to guide the design process, suggesting alternative materials or equipment that meet the project goals while keeping costs down. Throughout the project, as changes to the design occur, the estimator continually updates the budget.
The Advantages of the Design-Build Model
Many owners now prefer to use design-build because of its inherent flexibility. The advantages of design-build are numerous:
- Speed: Design-build streamlines the construction process. The construction phase can often begin before the final design is perfectly polished.
- Teamwork: It unites the design and construction teams. By placing construction under one team, communication and collaboration skyrocket.
- Risk Mitigation: Under a single design-build umbrella, if issues arise, adjustments can be made internally without costly change orders or legal battles between separate contracts.
- Efficiency: The benefits of design-build heavily favor streamlined project management. The unified design-build team achieves the project goals more efficiently, leading to a highly successful project execution.
Finding the Best Fit for Your Contracting Business
Ultimately, deciding the right project delivery method depends on the owner’s desire for control over the design versus their need for speed and budget certainty. While design-bid-build offers rigid control, design and construction services executed via a design-build contract offer unparalleled teamwork.
Understanding the nuances of design-build and design-bid-build ensures your mechanical estimating department is prepared for any construction project management scenario. Whether you are counting final drawings or conceptualizing a massive construction project, adapting your strategy is the true key to a successful project and a thriving business. If you need help managing these complex takeoffs to complete the project accurately, our dedicated estimating experts are here to help!
