Building a Chase in Construction: Complete Guide for Professionals
In modern construction, integrating building systems like plumbing, electrical wiring, HVAC ducts, or even communication cables requires smart routing solutions that are both functional and aesthetically clean. One of the most effective ways to achieve this is by building a chase—a concealed vertical or horizontal passage that houses these critical utilities. Whether you are working on a residential renovation, a new commercial build, or a complex multi-story development, understanding how to properly build a chase is essential.
This comprehensive guide explains everything about building a chase, including planning, design, construction, and compliance best practices.
🧱 What Is a Chase in Construction?
A chase is a built-in cavity or channel within a building, usually enclosed by walls, floors, or ceilings, designed to contain and conceal mechanical, electrical, or plumbing (MEP) components. The act of building a chase involves creating this enclosed path intentionally as part of the architectural or structural layout.
Chases can be vertical (from floor to floor) or horizontal (within walls or floors), and they can be made of wood, metal framing, or masonry, depending on the location and system requirements.
🔧 Why Build a Chase?
Building a chase offers several key advantages in construction projects:
- Conceals unsightly piping and wiring
- Protects utilities from physical damage
- Supports fire separation and noise control
- Makes maintenance easier with designated access
- Allows service systems to be centralized and organized
📌 Where Are Chases Commonly Built?
Chases are widely used across both residential and commercial buildings. Typical locations include:
| Area | Chase Usage |
|---|---|
| Bathrooms | Plumbing vents, water supply, and drain lines |
| Kitchens | Sink, dishwasher, and refrigerator plumbing |
| Utility Rooms | Water heaters, electrical panels, HVAC systems |
| Hallways | Vertical risers for electrical or telecom systems |
| Ceilings & Soffits | HVAC ductwork, vent pipes, lighting conduits |
| Between Units (in apartments or hotels) | Shared service walls with access to plumbing and electrical lines |
🛠️ Steps to Building a Chase
Step 1: Identify the Systems to Be Routed
Before any physical work begins, MEP coordination is crucial. Identify what systems will run through the chase:
- Plumbing lines
- Electrical conduits
- HVAC ducts
- Fire suppression systems
- Network or telecom cables
Step 2: Determine the Chase Size and Location
- Use architectural plans to designate vertical and horizontal chase paths.
- Calculate the total depth and width needed, considering insulation, pipe spacing, and accessibility.
- Ensure the chase doesn’t interfere with structural components like beams, joists, or load-bearing walls.
Step 3: Frame the Chase
Use wood or metal studs to frame the chase:
- For vertical chases, studs are typically framed floor-to-ceiling, often doubling the wall thickness.
- For horizontal chases, soffits or bulkheads may be created with framing that drops below the ceiling level.
- Include blocking or support brackets as required for heavy systems or to meet code.
Step 4: Install the Building Systems
With the frame in place, install the necessary utility systems:
- Maintain proper spacing between pipes and conduits.
- Ensure correct slope for drainage pipes (minimum 1/4 inch per foot).
- Avoid sharp turns or tight bends that restrict flow or access.
- Firestop penetrations using approved materials if passing through rated assemblies.
Step 5: Insulate and Soundproof (If Required)
Especially important in multi-unit buildings or where noise is a concern:
- Use acoustic batts or foam insulation to reduce sound transmission.
- Insulate hot water pipes to improve efficiency.
Step 6: Enclose and Finish the Chase
- Install drywall, cement board, or another appropriate enclosure.
- Add access panels where maintenance points (like shut-off valves or cleanouts) are needed.
- Finish with paint or other materials to match the surrounding area.
🧯 Fire Safety Considerations
Building a chase that intersects fire-rated walls or floors requires:
- Fire-rated gypsum board (Type X or higher)
- Mineral wool or firestop insulation
- UL-listed fire caulk or collars around pipe and conduit penetrations
- Proper detailing in compliance with the International Building Code (IBC) and NFPA 101
🧰 Materials Used in Chase Construction
| Component | Material Options |
|---|---|
| Framing | Wood studs, metal studs |
| Piping & Conduits | PVC, PEX, copper, EMT, flexible conduit |
| Insulation | Fiberglass, mineral wool, spray foam |
| Drywall/Enclosure | Standard or fire-rated gypsum board |
| Fireproofing | Intumescent caulk, firestop collars |
| Access Panels | Metal, plastic, or concealed hatch types |
🔎 Design Tips for Efficient Chase Construction
- Plan chase routes early in the project to avoid clashes with beams or HVAC systems.
- Group utilities that follow a similar path to reduce chase size.
- Keep chases aligned between floors for easier installation.
- Avoid overstuffing the chase—maintain minimum clearances around each pipe or conduit.
- Label all piping and wiring before closing the chase.
🚫 Common Mistakes to Avoid
- Improper sizing, resulting in tight or inaccessible chases.
- Lack of access panels, making repairs more invasive.
- Skipping firestopping, which can lead to serious code violations.
- Routing systems too close, increasing the risk of interference or heat transfer.
- Building chases in load-bearing areas without structural review.
📊 Comparison: Chase vs Shaft vs Fur Down
| Feature | Chase | Shaft | Fur Down |
|---|---|---|---|
| Purpose | Conceals pipes/wires within walls | Large vertical opening for ducts, elevators | Drops ceiling locally to hide systems |
| Size | Narrower, service-specific | Wide, multi-system vertical space | Shallow and limited in use |
| Accessibility | Often includes access panels | Restricted or service-access only | Low, easy to remove drywall for access |
| Common Use | Bathrooms, kitchens, closets | Mechanical rooms, stairwells | Small residential duct or pipe runs |
🏗️ When to Build a Chase in a Project
| Situation | Chase Needed? | Reason |
|---|---|---|
| Stacked bathrooms in multi-story units | ✅ Yes | Vertical chases align plumbing between floors |
| Concealing HVAC refrigerant lines | ✅ Yes | Protects lines and improves interior appearance |
| Retrofit projects with surface wiring | ❌ Optional | Surface mount may be easier unless aesthetics are a concern |
| Industrial-style open ceilings | ❌ No | Exposed systems are part of the design |
| Hotels and hospitals | ✅ Yes | Code-mandated service routing and fire-rated enclosures |
❓ FAQs: Building a Chase
1. What is the purpose of building a chase?
A chase is built to conceal plumbing, electrical, or HVAC systems in a clean, organized way while maintaining access and compliance with codes.
2. How thick should a chase wall be?
The thickness depends on what is being enclosed. For plumbing or electrical conduit, 6–12 inches is common. For HVAC ductwork, it may need to be even wider.
3. Can chases be built in load-bearing walls?
It’s not recommended unless specifically engineered. Chases should be placed in non-load-bearing partitions when possible.
4. Are chase walls fire-rated?
If they pass through fire-rated assemblies or contain fire-prone materials, fire-resistant materials must be used to meet code.
5. What materials are used to build a chase?
Typical materials include metal or wood studs, drywall, insulation, and firestop products, depending on code requirements and utility type.
6. Can I build a chase in an existing wall?
Yes, but retrofitting is more labor-intensive. You’ll likely need to open the wall, reroute systems, and ensure proper closure afterward.
7. Are access panels required in a chase?
Yes—especially where shutoff valves, cleanouts, or junction boxes are enclosed. Access is critical for future maintenance.
8. Do plumbing pipes in a chase need to be insulated?
Insulating hot water lines is recommended for energy efficiency. Drainpipes may be insulated for sound control.
9. Can different systems share the same chase?
Yes, but proper separation must be maintained. Electrical, gas, and water lines cannot directly touch each other and must follow local code spacing.
10. What happens if a chase is not properly sealed?
Unsealed chases may compromise fire safety, allow pest intrusion, or lead to moisture damage—all of which can fail inspections.
Conclusion:
Building a chase is a strategic, efficient solution to house the essential systems of a modern building without sacrificing visual appeal or safety. By carefully planning the layout, choosing the right materials, and adhering to construction codes, you ensure a functional infrastructure backbone that supports maintenance, aesthetics, and long-term performance. Whether in a single-family home or a high-rise commercial tower, chases are an indispensable element of smart construction.
