Planning a kitchen remodel is exciting—you’re probably already dreaming about new countertops, modern cabinets, and those appliances you’ve had your eye on. But before you start picking out paint colors, there’s one critical element that needs your attention: plumbing.

The plumbing work in your kitchen remodel might not be glamorous, but it’s the foundation that makes everything else possible. Whether you’re simply updating fixtures or completely changing your kitchen’s layout, understanding what plumbing is involved can save you thousands of dollars and prevent frustrating delays.

Let’s walk through everything you need to know about kitchen remodel plumbing—from the basics to the Twin Falls-specific considerations that can make or break your project.

Why Plumbing Planning Is Critical for a Kitchen Remodel

Poor plumbing planning is one of the most common—and expensive—mistakes homeowners make during kitchen remodels. When you don’t think through the plumbing early, you can end up with:

• Unexpected costs from having to relocate pipes after cabinets are installed
• Project delays while waiting for additional permits or materials
• Compromised layouts because your dream design doesn’t work with existing plumbing
• Code violations that fail inspection and require expensive corrections

Here in Twin Falls, we have some unique factors that make plumbing planning even more important:

Older Homes Present Special Challenges

Many Twin Falls homes were built in the 1960s through 1990s, which means they may have galvanized pipes, outdated layouts, or plumbing that doesn’t meet current building codes. Moving a sink or adding a dishwasher in an older home can be more complex than in newer construction. The pipes may be corroded, harder to access, or require complete replacement rather than simple modifications.

Our Hard Water Impacts Everything

As we’ve covered in our water quality guide, Twin Falls water measures 15-20 grains per gallon—that’s “very hard” water. This mineral content affects your plumbing decisions in several ways. New fixtures and appliances are immediately exposed to scale buildup, which can shorten their lifespan significantly. If you’re remodeling, it’s worth considering water treatment options at the same time to protect your investment.

Winter Construction Requires Extra Care

Idaho winters bring freezing temperatures that can affect plumbing work during your remodel. Exposed pipes during construction need protection, and any new plumbing should be properly insulated before walls are closed up. This is especially critical in Twin Falls, where temperatures can drop well below freezing.

The good news? With proper planning, you can avoid all these pitfalls and create a kitchen that works beautifully for years to come.

Key Plumbing Components for a Kitchen Remodel

Before you can plan effectively, you need to understand what plumbing components your kitchen remodel involves. Let’s break down the five main elements.

1. Water Supply Lines

Water supply lines are the pipes that bring hot and cold water to your sink, dishwasher, refrigerator, and any other water-using appliances or fixtures.

Material Choices Matter

You have several options for supply line materials, each with different costs and benefits:

• PEX (Cross-linked Polyethylene): The most popular choice for modern remodels. PEX costs $0.40-$2.00 per linear foot for materials and is flexible, making it easier to route through existing walls. It’s also resistant to scale buildup—a huge advantage with Twin Falls’ hard water. PEX doesn’t corrode and can expand slightly if water freezes, making it more resistant to burst pipes than rigid materials.
• Copper: Traditional and durable, but expensive. Copper pipes cost $2-$12 per linear foot depending on diameter and type. Copper lasts 50+ years and is naturally resistant to bacteria. However, it’s rigid (requiring more fittings and labor), more expensive to install, and can be affected by our area’s water chemistry over time.
• CPVC (Chlorinated Polyvinyl Chloride): A budget option at $0.50-$3 per linear foot. It’s rigid like copper but made of plastic. However, it can be prone to leaks if not installed properly, and many plumbers prefer PEX for its superior flexibility and durability.

Twin Falls Consideration: If your home has older galvanized pipes, this is the perfect time to replace them. Galvanized pipes corrode from the inside out, leading to reduced water pressure, discolored water, and eventual leaks. Many older Twin Falls homes still have these pipes, and remodeling provides the access needed to upgrade them.

Planning for Appliances

Don’t forget to plan water supply lines for:

• Refrigerator ice makers and water dispensers
• Dishwashers
• Pot fillers (if you’re adding this luxury feature)
• Instant hot water dispensers
• Water filtration systems

Each of these requires a dedicated supply line, typically ¼-inch or ½-inch diameter depending on the appliance.

2. Drainage and Waste Lines

Drainage is just as important as supply—and often more complicated. Every sink, dishwasher, and disposal needs proper drainage that flows correctly and vents properly.

The Critical Role of Venting

Many homeowners don’t realize that drain pipes need venting to work properly. Vents allow air into the drainage system, preventing the “glug-glug” sound of slow drains and ensuring water flows smoothly. If you’re moving your sink location significantly, you may need to add or relocate vent pipes—work that must be done before walls are closed up.

Proper Slope Is Essential

Drain pipes must slope at least ¼ inch per foot to drain properly. This might seem simple, but it becomes complicated when you’re routing drains through floors, around joists, and to your main waste line. Poor slope leads to slow drains, clogs, and potential backups.

Twin Falls Building Codes

All plumbing work in Twin Falls requires permits, and inspections ensure your drainage meets Idaho Plumbing Code requirements. Your plumber will need to verify proper venting, trap configuration, and drain sizing. Don’t skip the permit process—working without permits can result in double fees and problems when you sell your home.

3. Appliances Requiring Plumbing

Modern kitchens have more water-using appliances than ever. Each one needs proper planning.

Dishwasher Installation

Dishwashers need three connections:

1. Hot water supply line (typically ½-inch)
2. Drain line (connecting to your sink drain or garbage disposal)
3. Electrical connection (usually 120V)

The drain connection is particularly important—it needs to have a high loop or air gap to prevent backflow. In Twin Falls’ hard water, dishwashers are especially vulnerable to mineral buildup, so consider installing a water softener if you haven’t already. Hard water can reduce appliance efficiency by up to 48% and shorten lifespan considerably.

Refrigerator Water Lines

If your new fridge has an ice maker or water dispenser, it needs a ¼-inch supply line. This is one of the easier plumbing additions, but it needs to be properly secured and accessible for future maintenance. Make sure the connection includes a shut-off valve so you can disconnect the refrigerator without shutting off water to the entire kitchen.

Garbage Disposal Considerations

Garbage disposal installation costs $250-$650 for new installations, including the unit and labor. If you’re adding one for the first time, you’ll need:

• Electrical connection (dedicated circuit or existing outlet)
• Proper drain configuration
• Space under your sink for the unit

Disposals require specific drain arrangements, and the mounting system varies by brand. Your plumber should install this before the countertop goes in to ensure proper fit and function.

Pot Fillers and Special Features

Pot fillers—those convenient faucets mounted above your stove—are increasingly popular. They require running a cold water supply line to your cooktop area, which means opening walls and potentially routing pipes across your kitchen. Plan for this early so the rough-in work can be completed before finishes are installed.

4. Fixtures and Faucets

Your sink and faucet might seem straightforward, but there are important considerations.

Single vs. Double Basin Sinks

The sink configuration affects both drainage and countertop layout. Double basin sinks typically require two drain connections (though they can share a single trap), while single basins need just one. Large farmhouse sinks may require custom support structure and drain positioning.

Modern Faucet Options

Today’s kitchen faucets offer features like:

• Pull-down or pull-out sprayers
• Touchless operation
• Built-in water filtration
• Separate side sprayers
• Pot filler arms

Each feature has specific installation requirements. For example, touchless faucets need an electrical connection (usually battery-powered) and proper positioning for the sensor to work correctly.

Prep Sinks and Bar Areas

If you’re adding a second sink in an island or bar area, you’ll need complete plumbing for that location—supply lines, drainage, venting, and potentially a separate trap. This adds complexity and cost but provides valuable functionality.

5. Water Filtration or Softening Options

Given Twin Falls’ water quality, now is the perfect time to address filtration or softening.

Whole-House Water Softeners

If you don’t already have one, consider installing a water softener during your remodel. Installation typically costs $800-$3,000 depending on system capacity and features. A softener protects all your new plumbing, fixtures, and appliances from scale buildup, potentially adding years to their lifespan.

Point-of-Use Filtration

For just the kitchen, consider:

• Under-sink reverse osmosis systems: $250-$600 installed, providing purified water for drinking and cooking
• Faucet-mounted filters: $25-$100, an economical option that improves taste and removes chlorine
• Dedicated filtered water faucets: A separate tap for filtered water, keeping your main faucet uncluttered

These systems need space under your sink and proper drainage for the waste water (in the case of RO systems). Plan the cabinet layout accordingly.

Planning Your Kitchen Remodel Plumbing Layout

A successful kitchen remodel requires a methodical approach to plumbing planning. Here’s the step-by-step process:

Step 1: Evaluate Your Existing Plumbing

Before making any decisions, understand what you currently have:

• Where are your main water supply lines?
• Where does your drain line connect to the main waste line?
• What’s the condition of existing pipes?
• Are there any code violations that need correction?
• What’s the water pressure like?

A licensed plumber can assess your current system and identify potential issues. In Twin Falls homes built before 1990, this assessment often reveals galvanized pipes, inadequate venting, or outdated configurations that should be addressed during the remodel.

Step 2: Decide What’s Staying and What’s Moving

This is where kitchen remodel plumbing service costs can vary dramatically. Keeping your sink in its current location is the most economical option—you’re working with existing supply and drain lines. Moving the sink even a few feet can add $1,500-$3,000 or more to your plumbing costs, depending on how far it moves and what obstacles are in the way.

Cost Reality Check:

• Keeping plumbing in place: Minimal plumbing costs (just fixture updates)
• Moving fixtures within a few feet: $500-$1,500 additional
• Major layout changes: $1,500-$15,000+ depending on complexity
• Adding island plumbing where none existed: $2,000-$5,000+

Step 3: Map Out Supply and Drainage Lines

With your designer or plumber, create a detailed plan showing:

• Where each water supply line will run
• Drain line paths and venting requirements
• Shut-off valve locations (critical for future maintenance)
• Access panels if needed for hard-to-reach plumbing

This mapping reveals potential conflicts before construction starts. For example, you might discover that your dream island sink location conflicts with floor joists, requiring expensive structural modifications.

Step 4: Plan the Rough-In Timeline

Plumbing work happens in two phases:

1. Rough-in: Installing pipes before walls, cabinets, and finishes go in (typically takes 1-2 days)
2. Finish work: Installing fixtures, faucets, and appliances after everything else is complete (1-2 days)

The rough-in must be completed and inspected before any walls are closed or cabinets installed. Plan your construction timeline accordingly. Most kitchen remodels take 6-12 weeks for construction, with plumbing rough-in happening in the first 1-2 weeks.

Twin Falls Specific Considerations

In older Twin Falls homes, accessing plumbing can be more challenging. Many homes have:

• Limited crawl space access
• Concrete slab foundations (making under-floor work impossible)
• Plaster walls (harder to repair than drywall)
• Plumbing tucked behind finished spaces

Your plumber needs to assess access before providing accurate quotes. Sometimes the most economical solution is routing new pipes through alternative paths rather than trying to work with inaccessible existing locations.

Common Plumbing Challenges in Twin Falls Kitchen Remodels

Let’s talk about the issues that come up frequently in our area—so you can plan for them.

Challenge #1: Hard Water Scale on New Fixtures

You invest in a beautiful new faucet and within months, it’s covered in white mineral deposits. Twin Falls water measures 15-20 grains per gallon, which means scale builds up quickly on any surface water touches.

Solution: Install a water softener or point-of-use filtration system during your remodel. The cost of treatment is far less than replacing fixtures and appliances prematurely or dealing with ongoing cleaning frustration. Water softeners typically pay for themselves within 18-24 months through reduced maintenance and longer appliance life.

Challenge #2: Limited Access in Older Homes

Older Twin Falls homes often have:

• Tight crawl spaces (sometimes just 18-24 inches of clearance)
• Finished basements where plumbing runs above the ceiling
• Walls packed with insulation, making new pipe routing difficult

Solution: Work with an experienced local plumber who knows Twin Falls home construction. Sometimes creative solutions—like routing pipes through cabinets or using alternative paths—are more practical than the “textbook” approach. This is where experience really matters.

Challenge #3: Winter Construction Complications

If your remodel happens during Idaho winter (which can stretch from November through March), frozen pipes are a real concern during construction.

Solution:

• Schedule plumbing rough-in during warmer months if possible
• Keep heat running in the home during construction
• Have your plumber use heat tape or temporary insulation on exposed pipes
• Plan the work so plumbing isn’t exposed to freezing temperatures for extended periods

Professional plumbers know how to work safely in cold weather, but it does require extra precautions and may slow the timeline slightly.

Challenge #4: Code Compliance in Older Homes

When you remodel, you’re required to bring the work up to current code—which might reveal existing violations that need correction.

Common code issues in older Twin Falls kitchens:

• Inadequate venting on drain lines
• Missing shut-off valves
• Improper drain slopes
• Outdated materials (like polybutylene pipes)
• Cross-connections that allow backflow

Solution: Budget for potential code upgrades. A good plumber will identify these issues during the initial assessment so they don’t surprise you mid-project. While it adds to costs, bringing everything to code protects your home value and ensures your remodel passes inspection.

How to Save Time and Money During Your Kitchen Remodel

Smart planning can significantly reduce your kitchen plumbing costs without cutting corners. Here’s how:

1. Minimize Layout Changes

The single biggest way to save on plumbing costs is keeping your sink, dishwasher, and other fixtures in their current locations (or very close). Even moving a sink three feet can require new drain lines, vent modifications, and extended supply lines—work that adds up quickly.

If your current layout functions well, consider whether the benefits of moving fixtures justify the cost. Sometimes the answer is yes (if the current layout is truly dysfunctional), but often minor adjustments can achieve most of your goals at a fraction of the cost.

2. Plan Appliance Placement Carefully

Group water-using appliances together when possible. Placing your dishwasher next to the sink allows it to share the drain connection, saving on materials and labor. Similarly, locating your refrigerator near existing water lines simplifies the ice maker hookup.

Think about future flexibility too. If you might add an appliance later (like an under-counter ice maker or second dishwasher), ask your plumber to rough in the connections now while walls are open. Adding a capped line during construction costs far less than opening walls later.

3. Consider Upgrade Opportunities

While your walls are open and plumbers are on-site, it’s the ideal time to address related improvements:

• Upgrade old pipes: If your home has galvanized or other outdated piping, replace it now
• Add shut-off valves: Every fixture should have accessible shut-offs for future maintenance
• Install water treatment: Add filtration or softening while plumbing is accessible
• Improve drainage: If you’ve had slow drains, fix the underlying issues during the remodel
• Add a floor drain: If your kitchen could benefit from one (like under the sink), now’s the time

These upgrades cost less when done as part of a larger project than as separate jobs later.

4. Hire Licensed and Insured Local Plumbers

This might seem obvious, but it’s worth emphasizing. Licensed plumbers:

• Understand local code requirements
• Pull proper permits and schedule inspections
• Guarantee their work
• Have insurance to protect you from liability
• Know Twin Falls-specific challenges (like hard water and older home construction)

Yes, licensed plumbers cost more per hour than handymen or unlicensed contractors. But mistakes in plumbing are expensive to fix and can cause thousands of dollars in water damage. The peace of mind and quality work are worth the investment.

5. Schedule Plumbing Work Before Finishing

This should go without saying, but timing matters. The sequence should be:

1. Demolition and rough-in plumbing
2. Inspection and approval
3. Wall closing and preparation
4. Cabinet installation
5. Countertop installation
6. Finish plumbing (faucets, fixtures, appliances)

Never let cabinets or countertops be installed before the rough-in plumbing is inspected and approved. If issues are found during inspection, fixing them after cabinets are in place is exponentially more expensive and disruptive.

When to Call TRW Plumbing for Your Twin Falls Kitchen Remodel

Kitchen remodel plumbing requires expertise, local knowledge, and attention to detail. At TRW Plumbing, we’ve helped countless Twin Falls homeowners navigate the plumbing aspects of their kitchen remodels—from simple fixture updates to complete layout transformations.

Why Twin Falls Homeowners Trust TRW Plumbing:

• 24 years of experience with southern Idaho homes and construction
• Licensed, bonded, and insured for your protection
• Family-owned and operated by Trevor Williams, a third-generation plumber
• Expert knowledge of Twin Falls water quality issues and older home plumbing
• Transparent pricing with detailed estimates before work begins
• Full-service capability from planning through final installation

We work with homeowners and contractors to ensure plumbing integrates seamlessly with your kitchen design. Whether you’re planning a minor update or a complete transformation, we’ll help you understand what’s involved, what options make sense for your home, and how to protect your investment.

Ready to discuss your kitchen remodel? Call us at (208) 423-3276 or visit our website to schedule a consultation. We offer evening and weekend appointments and can coordinate with your contractor or designer to ensure your project stays on schedule.

Frequently Asked Questions About Kitchen Remodel Plumbing

What plumbing is typically required for a kitchen remodel in Twin Falls?

A typical kitchen remodel requires water supply lines (hot and cold) for the sink, dishwasher, and refrigerator; drain lines with proper venting for the sink and dishwasher; garbage disposal installation (if adding one); and shut-off valves for each fixture. The exact requirements depend on your layout changes—keeping fixtures in place requires minimal plumbing work, while moving the sink or adding an island with plumbing can require extensive new lines, venting modifications, and drain rerouting. In Twin Falls, many older homes also benefit from upgrading outdated galvanized pipes during remodels.

How much does kitchen remodel plumbing cost in Idaho?

Kitchen remodel plumbing costs vary widely based on scope. Basic fixture replacements without moving plumbing typically cost $1,000-$4,000. Moving plumbing or changing layouts costs $1,500-$15,000+ depending on complexity. Individual components include: dishwasher installation ($700-$2,000), garbage disposal installation ($250-$650), new faucet installation ($500-$2,500 including fixture), and water line installations ($75-$130 per line). In Idaho, labor rates range from $45-$150 per hour depending on the plumber’s experience. Always get detailed written estimates that break down materials and labor.

Can I move my sink or dishwasher without repiping my home?

In most cases, yes—but it depends how far you’re moving them. Moving a sink a few feet along the same wall is relatively straightforward, usually requiring extended supply lines and drain modifications. Moving to a different wall or adding an island sink is more complex, potentially requiring new vent pipes, main drain connections, and sometimes floor or ceiling work to route pipes. You won’t necessarily need to repipe your entire home, but the affected area will need new plumbing. The cost varies from $500-$5,000+ depending on distance and obstacles. A licensed plumber can assess your specific situation and provide options.

Do I need to upgrade old pipes during a kitchen remodel?

While not always required, it’s often wise—especially in Twin Falls homes built before 1990. If your home has galvanized pipes (common in older homes), they’re likely corroded inside, causing low water pressure and rusty water. Remodeling provides the perfect opportunity to replace them since walls are already open. Similarly, if you have polybutylene pipes (used in 1980s-1990s), they should be replaced as they’re prone to failure. Even if pipes aren’t failing yet, upgrading to modern materials like PEX during your remodel costs far less than doing it as a separate project later. Your plumber can inspect existing pipes and recommend whether replacement is necessary.

How does Twin Falls’ hard water affect kitchen plumbing?

Twin Falls water measures 15-20 grains per gallon—considered “very hard”—which significantly impacts kitchen plumbing. Mineral buildup (scale) accumulates inside pipes, on faucet aerators, in dishwashers, and on any surface water touches. This reduces water heater efficiency by up to 30%, shortens appliance lifespan by 2-4 years, clogs aerators and spray heads, and creates visible deposits on fixtures. During a remodel, consider installing a water softener or under-sink filtration system to protect your investment. The cost of water treatment is far less than replacing prematurely failed appliances and fixtures. Many Twin Falls homeowners find that softeners pay for themselves within 18-24 months through reduced maintenance and longer equipment life.

Should I install a garbage disposal or water filtration during a remodel?

Both are excellent additions during a kitchen remodel. Garbage disposals cost $250-$650 installed and make cleanup easier while reducing drain clogs from food debris. They’re especially practical if you don’t have easy compost access. Water filtration addresses Twin Falls’ hard water and chlorine taste. Options include whole-house softeners ($800-$3,000), under-sink reverse osmosis systems ($250-$600), or simpler faucet-mounted filters ($25-$100). Since your plumbing is already accessible during the remodel, installation costs are lower than adding these features later. Both improvements increase your home’s functionality and value while protecting your plumbing investment from mineral damage.

What permits are needed for kitchen plumbing changes in Twin Falls?

All plumbing work in Twin Falls requires permits from the city Building Safety Department. This includes relocating fixtures, adding new plumbing, and installing appliances with plumbing connections. Permit costs typically range from $500-$2,000 depending on project scope, with fees doubling if work starts without permits. Your licensed plumber should handle permit applications and schedule required inspections. The city inspects rough-in plumbing before walls close and may require final inspections after completion. Don’t skip permits—unpermitted work can create problems when selling your home and may void insurance claims if plumbing issues cause damage. Contact Twin Falls Building Safety at (208) 735-7238 for specific requirements.

How long does it take to complete plumbing for a kitchen remodel?

Plumbing work happens in two phases. Rough-in (installing pipes before walls close) typically takes 1-2 days for straightforward projects, potentially longer if you’re moving fixtures significantly or dealing with access challenges in older homes. After rough-in inspection approval, walls can be closed and remodel continues. Finish work (installing faucets, fixtures, and hooking up appliances) takes 1-2 days and happens after cabinets and countertops are in place. The overall kitchen remodel typically takes 6-12 weeks total, with plumbing rough-in happening in the first 1-2 weeks. Timeline can extend if permits take longer than expected or if unexpected issues (like corroded pipes) are discovered during demolition.

Can I add a second sink or prep sink during a remodel?

Yes, adding a prep sink, bar sink, or island sink is definitely possible during a remodel. However, it requires complete plumbing infrastructure—supply lines (hot and cold), drain line, and proper venting. Adding a sink to an island is particularly complex because you’ll need to route pipes under the floor or through cabinets, and venting can be tricky (may require a special island vent or air admittance valve). Costs typically range from $1,000-$3,500 for adding a second sink, depending on location and access. The benefit is significant increased functionality, especially in larger kitchens where multiple people cook together. Your plumber can evaluate whether your specific location works and what modifications are needed.

How do I plan the plumbing layout for my kitchen efficiently?

Start by evaluating your current plumbing—where are supply and drain lines now? Work with your designer and plumber together to map out fixture locations before finalizing cabinet layouts. The most efficient approach keeps major plumbing near existing locations (within 3-5 feet minimizes costs dramatically). Group water-using appliances together when possible—dishwasher next to sink, refrigerator near existing water lines. Plan for the future by roughing in capped connections for potential additions. Schedule your plumber early in the design phase, not after cabinets are ordered—they can identify potential issues and suggest cost-effective solutions. Always verify that your dream layout is actually feasible before committing to specific cabinet configurations or appliance placements.

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