Building Chase in Construction: Definition, Purpose, and Best Practices

In the realm of commercial and residential construction, a building chase plays a critical role in managing infrastructure systems without compromising architectural aesthetics. Whether you’re an architect, contractor, or building owner, understanding what a chase is and how to use it effectively can streamline building performance and reduce long-term maintenance issues.

In this comprehensive guide, we’ll dive deep into:

• What a building chase is
• Types of chases
• Importance in modern construction
• Design and installation best practices
• Common materials
• Code requirements and fire safety considerations
• Mistakes to avoid
• And much more

What Is a Building Chase?

A building chase is a vertical or horizontal enclosed space built within a structure to house mechanical, electrical, or plumbing (MEP) systems. It acts as a dedicated passageway for routing pipes, conduits, wires, ducts, and other infrastructure components.

Key characteristics of a chase:

• Typically constructed from drywall, plywood, or metal studs
• Can run vertically through floors or horizontally within ceilings or walls
• Enclosed for fire safety, noise reduction, and aesthetics
• Accessible via removable panels or hatches

Types of Building Chases

There are several types of chases depending on the system being routed and the direction of installation:

1. Plumbing Chase

• Used to conceal water supply lines, waste pipes, and vents
• Often includes insulation to reduce noise from flowing water
• Can include clean-out access panels for maintenance

2. Duct Chase (HVAC)

• Houses air ducts for supply and return airflow
• Usually oversized to accommodate insulation and air circulation needs
• Must be sealed properly to prevent air leaks

3. Electrical Chase

• Contains conduits, electrical cables, and sometimes communication wiring
• Must be compliant with NEC (National Electrical Code)
• Fire-rated if passing through multiple floors

4. Vertical Chase

• Runs from the base to the top of a multi-story building
• Ideal for systems that need to rise from the mechanical room to upper floors
• Usually enclosed in shafts or wall cavities

5. Horizontal Chase

• Runs across a floor or ceiling to route utilities laterally
• Can be placed between joists or within drop ceilings
• Often used in apartment units and commercial spaces

Why Building Chases Are Essential

Aesthetic Appeal

Chases allow MEP systems to be hidden from view, resulting in a clean, streamlined interior.

Fire Safety

Properly constructed chases help contain fire and smoke, especially when built with fire-rated materials and equipped with firestopping seals.

Ease of Maintenance

Removable panels and clearly mapped routes enable technicians to perform maintenance without damaging structural or interior finishes.

Noise Reduction

Pipes and ducts can be noisy. A chase with sound-dampening materials helps minimize acoustic disturbances, especially in multi-family homes or hotels.

Future-Proofing

Well-planned chases can allow for easy upgrades or retrofits of plumbing, HVAC, or electrical systems without extensive demolition.

Design Considerations for Building Chases

To ensure functionality and compliance, consider the following factors during the design phase:

1. Space Planning

• Allow enough clearance for service access
• Include extra room for insulation and code-mandated separation distances

2. Accessibility

• Install access panels at strategic points
• Ensure critical joints and valves can be reached

3. Ventilation

• Some chases may need passive or mechanical ventilation (e.g., to prevent heat build-up in electrical chases)

4. Moisture Management

• Seal all chase penetrations
• Use vapor barriers if needed
• Avoid placing plumbing chases in exterior walls in cold climates

Typical Materials Used in Building Chases

Fire-Rated Building Chases

When a chase penetrates through multiple floors or fire-rated partitions, it must comply with fire code regulations. These include:

• Fire-rated drywall assemblies (1-hour, 2-hour, etc.)
• Fire dampers in HVAC chases
• Fire collars or wraps around plastic pipes
• Sealed penetrations with approved fire caulks or putties

Check local building codes (e.g., IBC – International Building Code) and consult with a fire protection engineer to ensure compliance.

Installation Best Practices

✅ Pre-Construction Coordination

• Collaborate with MEP engineers and architects early
• Integrate chases into the BIM model (if applicable)

✅ Clearly Marked Blueprints

• Ensure all chases are clearly labeled and detailed in plans
• Avoid routing conflicts with structural components

✅ Use of Firestop Systems

• Apply UL-listed firestopping materials where required
• Document all fire-rated assemblies for inspection

✅ Label Systems

• Label pipes, ducts, and cables inside the chase
• Attach system maps near access panels for future reference

Common Mistakes to Avoid

• Undersizing the chase: Leads to cramped systems and overheating
• Ignoring code requirements: Especially regarding firestopping and separation distances
• Poor access design: Makes future repairs difficult
• Water leaks in plumbing chases: Can cause mold if not detected early
• Uninsulated chases: May lead to condensation or sound transfer

Applications of Building Chases in Real Projects

• High-rise buildings: Vertical chases run mechanical systems to upper floors
• Hospitals: Specialized chases for medical gas and data wiring
• Hotels: Plumbing chases behind back-to-back bathrooms reduce cost
• Warehouses: Large HVAC chases for climate control in expansive spaces
• Residential homes: Chases between walls for running plumbing or media cables

The Future of Chasing in Construction

With the rise of modular construction and prefabricated MEP systems, chases are being planned with greater precision. Some trends include:

• Pre-insulated chase modules for rapid installation
• Flexible conduit systems for easier re-routing
• Smart monitoring inside chases for leak or fire detection
• Green building practices, such as reusing chase spaces for dual purposes

Conclusion

A building chase is much more than just a hollow box behind your wall. It’s a carefully planned space that holds the lifelines of your building — from water and air to electricity and communication. A well-designed chase enhances aesthetics, improves safety, and supports long-term maintenance, making it a key feature in both new construction and renovations.

FAQs about Building Chases

Q1: What’s the difference between a chase and a shaft?

A chase is a smaller, often wall-integrated space for pipes and wires, while a shaft is a large, vertical enclosure (like an elevator shaft or mechanical shaft) used for major systems like ductwork or plumbing risers.

Q2: Do building chases need to be fire-rated?

If a chase penetrates fire-rated walls or floors, or if it houses systems that could contribute to fire spread (like plastic pipes), then yes, it must be fire-rated per building code.

Q3: Can a chase be retrofitted into an existing building?

Yes, but it may require demolition or rerouting of existing systems. Proper planning and structural review are essential to retrofit a chase safely.

Q4: Are there code requirements for chase sizing?

Most codes don’t specify exact chase dimensions, but they do regulate clearance around systems, access requirements, and firestopping. Always refer to local codes and manufacturer guidelines.

Q5: Can I use the same chase for multiple systems (e.g., plumbing and electrical)?

It’s not recommended to mix systems within the same chase unless it’s allowed by code. Some systems must be physically separated due to safety or performance issues.

Q6: How do you prevent mold in a plumbing chase?

Use moisture-resistant materials, seal all joints, and install access panels for inspection. Detect and repair leaks promptly, and consider installing smart leak detectors.

If you need more in-depth guidance on a specific type of chase system or want to optimize MEP layout for your next project, consult with a licensed construction engineer or architect.