The MEP Change Saved Money. Who Proved It Still Worked?

Value engineering is a double-edged sword.

A well-developed proposal can reduce cost while preserving function, safety, quality and long-term performance. A poorly reviewed proposal can make installation easier for one party and leave the owner with years of access, maintenance or operational problems.

That risk is particularly important in MEP work because many value-engineering decisions are made during construction. At that stage, the contractor is naturally focused on procurement, installation sequence, labor and immediate constructability.

Those concerns matter, but they are not the whole life of the system.

The contractor sees installation. The owner lives with the result.

The owner, design team and general contractor have to look beyond the immediate saving.

They should ask whether the proposed change affects:

• the required function and capacity;

• code and project specifications;

• equipment efficiency and expected service life;

• access for testing, operation and maintenance;

• replacement clearances;

• routing and coordination with other trades;

• supports, openings and installation sequence;

• procurement and schedule;

• commissioning; and

• long-term operating cost.

SAVE International describes value methodology as a multidisciplinary, function-based process that balances performance, quality, safety and cost. That is different from replacing a component or deleting scope only because the first cost is lower.

An access panel does not guarantee access

One recurring coordination problem illustrates the difference.

A plumbing valve may be modeled correctly above a ceiling, with an access panel placed directly below it. On plan, the requirement appears to be satisfied.

Then another trade routes a duct below the valve.

The access panel still exists. The valve is still visible in the model. But a technician may not have a workable path to reach, operate, remove or replace it.

The same issue occurs with switches, disconnects, dampers, cleanouts and other serviceable devices. Teams often coordinate the opening without coordinating the human movement and tool space required to use it.

DDG uses no-fly zones to make access visible

For devices that require access, DDG commonly models a 3- to 4-foot coordination zone below the valve, switch or device. This is a DDG practice used to make access conflicts visible. It is not presented as a universal code dimension. The zone should be adjusted for the device, manufacturer instructions, owner standards, project requirements and the actual maintenance task.

If another trade enters that modeled zone, the condition appears as a coordination issue. The team can then decide whether to:

• move the valve or device;

• reroute the crossing service;

• adjust the access-panel location;

• confirm a different workable access path; or

• obtain a design decision when the change affects the intended system.

This approach turns an operational concern into something the coordination process can detect before the ceiling is closed.

BIM should test the proposal, not decorate it

When a value-engineering option is proposed, the model should help the team test the full consequence.

The review should compare the existing and proposed conditions and document:

1. the function that must be preserved;

2. the initial cost difference;

3. installation and schedule effects;

4. spatial and multidisciplinary impacts;

5. code and specification review;

6. access, maintenance and replacement requirements;

7. energy and lifecycle implications;

8. commissioning and acceptance requirements; and

9. the party approving the final decision.

The approved option must then reach the drawings, specifications, BIM model, submittals, procurement package, installation information and commissioning plan. A value-engineering decision that remains only in a meeting log is likely to be interpreted differently downstream.

The strongest value-engineering proposals do more than show a saving. They show how the revised solution was checked and how the owner will continue to receive the required function after the construction team has left.

If nobody can demonstrate that the new arrangement remains installable, accessible, maintainable and operational, the project has not finished value engineering. It has only moved cost from one stage to another.

Sources

• SAVE International: About the Value Methodology

• SAVE International: Function Analysis Guide