The Top 5 Costly Mistakes in Multifamily Design (and How You Could Be Saving Money with Advanced MEP)

By IES | 05/04/2025 |

Large-scale building projects can rack up unexpected costs quickly. Change orders, rework, and waste can blow budgets by thousands of dollars, along with increased carrying costs for construction loans.

However, many of these issues can be avoided when the right systems are in place. And it starts with advanced MEP in the planning stages.

5 Costly Mistakes to Avoid

1: Poor Communication

According to Navigant Construction, the average RFI costs around $1,080, with an average resolution of 12 days and as many as 22% going unanswered. Each time a team needs to stop and ask questions, that’s time and money wasted. If your contractors don’t have a clear communication protocol, you will see higher labor costs, more waste, and more frustration and mistakes.

2: Unclear Plans

Many of the RFIs stem from confusion around the plans for the building projects. When diagrams, designs, and instructions aren’t clear, the construction teams need to go back to architects and engineers to resolve the confusion. Even worse, these teams may not catch problems until after the construction is underway.

3: Rework and Mistakes

When teams have to start over on sections of a multifamily building project, costs could double quickly. Poorly designed mechanical, electrical, or plumbing systems can interfere with each other, as well as with framing and finishing spaces. Reworking designs on-site is incredibly wasteful, and it could push timelines back by months.

4: Late-Stage Collaboration

Construction projects have long been run as “silo” endeavors: each discipline works independently, one step at a time. In this protocol, collaboration is either late in the planning and design phases or not present at all. Late (or completely absent) collaboration is the root cause of rework and RFIs since each component rarely considers the others until a conflict arises.

5: Inefficient Systems

The lifecycle costs of MEP systems can take a back seat to budget concerns. Upfront savings may be appealing to stay on budget, but outdated, inefficient, or problematic HVAC and electrical choices can result in steep increases in maintenance, operational, repair, and replacement costs. Cutting corners on plumbing systems can increase energy costs as well, but it can also result in major repair issues if the plumbing leaks, gets clogged or broken, or corrodes prematurely.

Preventing Expenses from Day One

So, what’s the key takeaway from all these ugly problems? In two words, plan ahead. The earlier your teams work together, the fewer mistakes they’ll encounter at the job site.

Cross-Discipline Input

Collaborative planning can impact every step of the building process in significant ways. By combining disciplines from the beginning, multifamily and commercial building projects can save time, money, and labor. It also opens the door to more advanced MEP planning that can reduce costs beyond avoiding rework.

Clear Processes and Goals

When processes aren’t clearly defined, work can slow to a crawl. Likewise, if GCs, engineers, and project managers aren’t on the same page about the end goal, decisions are harder to make confidently at later stages in construction. Cooperative goal setting, vision casting, and process design can help every component work together smoothly.

Precise Designs and Plans

General construction and MEP design are closely tied together, and unclear plans can lead to costly mistakes. Modern design software allows MEP engineers to create more precise plans so that contractors have fewer questions during the construction process.

Open Communication

Open lines of communication help projects stay on schedule and on budget. Instead of cutting mechanical, electrical, and plumbing designers out of the construction process, project managers can help contractors overcome issues more efficiently by including engineers in clarifications. Likewise, having contractors available to answer questions and present concerns during the planning process can prevent issues once construction starts.

Saving Money with Advanced MEP

Wasted time, materials, and labor can produce significant costs during a large-scale building project. Early planning with more detailed and precise designs equates to reduced costs, making it simple to save money with advanced MEP incorporated at the start of a project rather than fixing problems during construction.

Fewer Clashes

The precision of digital drafting systems eliminates many clashes that can occur during construction when using conventional drafting and plans. Exact locations, measurements, and dimensions make it possible to reduce rework by as much as 50 percent while also reducing costs by as much as 30 percent.

More Efficient Designs

Digital drafting software allows mechanical engineers to optimize systems for various purposes, including energy efficiency, cost, and lifecycle management. Advanced MEP can help commercial and multifamily building projects save money long after planning and construction is complete.

Off-Site Design and Fabrication

By bringing all disciplines together at the planning stage, advanced MEP design allows projects to explore cutting-edge fabrication techniques that change workflow by moving parts of the building process into warehouses instead of the work site. Off-site fabrication reduces worksite labor requirements and allows different components to be built simultaneously without interference.

New Technologies

Early planning allows MEP engineers to integrate innovative technologies into designs, including automation and energy-saving tools that can extend the lifetime of a building’s components while reducing costs and maintenance needs.

Advanced MEP Tools and Processes

To reap the benefits of advanced MEP, you need the right tools. We’re utilizing BIM and design software that makes it possible to plan intricate details that prevent the need for extensive rework, clash resolution, and requests for information.

Design and Planning Tools

Moving designing and drafting from paper to computer solves many of the most expensive mistakes project managers encounter during a multifamily building project.

Autodesk Revit

Revit helps architects, structural engineers, MEP engineers, and contractors collaborate on projects at every stage of development. The software allows users to model shapes in 3D to build out systems and structures with more accuracy and less error, providing instant feedback and revisions to all plan elements.

Trimble

Trimble is a digital design platform for construction and maintenance technology that moves the design process into the cloud for faster and more accurate collaboration between different disciplines. Trimble can help project managers cut rework in half and reduce costs by almost one-third.

Applying Advanced MEP to Construction

The addition of BIM systems like Revit and Trimble can transform multifamily building projects through innovative design and fabrication techniques. And in doing so, advanced MEP can help project managers save money and resources.

SIP

Structural insulated panel (SIP) construction provides ultra-tight envelopes that far surpass the energy efficiency of conventional construction. SIPs can be cut to specified dimensions off-site and easily transported and assembled on-site. The trick is having precise plans before fabrication and construction.

However, working with a tight envelope requires additional design effort to ensure proper ventilation and airflow. It also requires early input from other disciplines to plan electrical, plumbing, HVAC, and fenestrations before fabrication.

Modular Construction

Multifamily building projects have started using modular construction to streamline workflow and expedite project completion through off-site construction. Entire rooms, including all plumbing, electrical, and HVAC components, can be designed and built in a warehouse, transported to the worksite, and assembled.

Modular construction eliminates weather-dependent construction schedules and reduces worksite traffic. While it can provide more efficient and cost-effective construction, this type of construction is dependent on precision at the design stages so that all modules fit together properly. Digital drafting software and BIM-centered collaboration are key.

IES and Your Next Project

We’ve been using innovative MEP engineering and design tools to help investors build state-of-the-art multifamily and commercial spaces since 2005, bringing energy-efficient and attractive spaces into communities through advanced MEP.

We’ll help you save money, reduce waste, improve efficiency, and minimize labor needs from the start of your project with precise and clear designs that cut the need for RFIs and rework so your teams can get their jobs done faster and with fewer clashes.

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