Master Bedroom Addition: Costs & Tips For 2024

In many areas of Los Angeles and Southern California, most homes were originally built without a true master bedroom suite. Although this was the standard many years ago, many homeowners today prefer to have a private master bedroom suite with its own lavish bathroom and walk-in closet. That’s where the master suite addition comes into play—a popular home improvement project for locals looking to upgrade their living spaces. 

In this blog, we’ll share some ideas, the typical master suite addition cost, and tips about adding a master suite to your home and finding the best contractors for your project.

Modern and Open Master Bedroom Addition

Here at GreatBuildz, we speak with clients every day who are considering a master bedroom addition to their home. GreatBuildz is a free service that connects homeowners with reliable, pre-screened home contractors in Los Angeles, Orange County, Ventura & San Diego, then provides ongoing project support to ensure a stress-free experience.

Key Takeaways

  • A master suite addition typically includes a bedroom, closet, and bathroom. The cost varies based on the inclusion of wet spaces like bathrooms, plumbing requirements, and the overall size of the addition.
  • In the Los Angeles area, a master suite addition of 400-500sf can cost between $100,000-$200,000. A budget of around $150,000 is a common starting point. Additional costs may arise based on factors like structural needs for a second-floor addition.
  • Certain construction elements, such as foundation, framing, and roofing, contribute to fixed costs. Variable costs depend on choices like HVAC systems, windows, doors, flooring, and bathroom fixtures.
  • The journey involves research on costs, engaging an architect for plans, selecting a reliable contractor, obtaining permits, and overseeing inspections. Timelines for plans and construction can vary, but having an experienced contractor early in the design phase can optimize costs.
  • Vetting contractors is crucial. Recommendations from trusted sources, thorough online reviews, license verification, and checking insurance coverage are essential steps. Getting multiple bids, reviewing each for consistency, and preparing for cost and time contingencies ensure a smoother experience.
  • Prioritize homeowner’s insurance discussions before initiating the project, ensuring coverage during construction and adjusting policies post-addition completion.
  • Budget for unforeseen costs (10-20% contingency) and anticipate potential delays, recognizing that inspections, repairs, and changes can impact project timelines.


How much does it cost to add a master bedroom and bath suite?

Fine Art Master Bedroom Addition

A master suite addition is usually comprised of a bedroom, closet, and bathroom.  This space is a combination of a “dry” space (bedroom, closet) and a “wet” space (a master bathroom).  It should be pretty obvious that the wet space is much more costly to build because 1) it requires running plumbing lines (water lines and waste lines), and 2) it requires a lot more fixtures like tile, tub, vanities, etc.  So, it’s important to keep in mind that if you’re just adding bedroom space with no bathroom, your costs are going to be significantly lower than a full suite.

A master suite remodeling floor plan can be as small as 300sf, but this would function more like a guest suite with a small bedroom and basic bathroom & closet.  Most people choose to create a master suite addition that’s between 400sf and 500sf or even larger.  This floorplan can be a 20×20 addition (400 sq ft master suite addition), but doesn’t necessarily have to be square.

The price in Los Angeles and surrounding counties for a master suite addition of this size will range from $100,000 to $200,000.  A common average cost and a good budget to start with is around $150,000. This price assumes a single-story addition. The costs would be significantly higher if you’re building a second-floor addition on top of your existing one-story home due to the need for structural support, stairs, etc. 

Although you can start your budgeting with a basic cost calculator, the only way to get accurate cost figures is to discuss your project and plans with a few good general contractors.

What items affect the master bedroom addition cost?

Tan Master Bedroom Addition

Let’s discuss the items that go into a master suite addition and how they may affect your total costs.  I’ll start with the ‘rough’ construction items that are required for any addition.  Every addition will require:

  • Rebar and concrete foundation
  • Wall and roof framing
  • Drywall
  • Stucco or other exterior material
  • Electrical wiring
  • Plumbing (water lines & waste lines)
  • Roofing material
  • Insulation

These are items and costs that you cannot control, for the most part, because they are fixed costs and aren’t optional. Also, keep in mind that your costs may be higher in specific situations.  For example, if your electrical panel is at capacity, you may need to upgrade it to accommodate new electrical circuits in your additional space.

Also, if your existing house is on a slab foundation (not a raised foundation), it will be more difficult to connect the plumbing (waste lines) and could increase costs. Finally, if your roofing material is old or unique, it might be difficult to match it in constructing the addition, creating the possible need to re-roof the entire home.  These are important items to discuss with your architect and general contractor.

Alternatively, there are a whole host of items in a master bedroom addition that can affect your costs & budget significantly based on your choices, with some examples below:

  • HVAC: Can you connect your master addition to the existing system?  If your system isn’t ‘large’ enough to cover the added square footage, you may need to replace it with a larger system. Alternatively, you can install a new ‘ductless’ HVAC system just for the master suite
  • Windows: The costs of windows vary greatly based on your selection. Presumably, you’ll want to choose windows that approximate the existing windows in your house.
  • Doors (interior/exterior/closet): A few interior doors and closet doors shouldn’t break the bank, but if you include patio or French doors from your new bedroom to the outside, these can get expensive, depending on your selection.   
  • Flooring: Cost will vary greatly depending on whether you select a cheaper material like carpet or vinyl versus a more expensive option like hardwood, stone, or tile.

Master Bedroom Addition: Costs & Tips For 2024 1

  • Closet cabinets/organizers: Although these are only optional, many people can’t imagine a walk-in closet without some kind of organizing system including cabinets/shelves/etc. These can be purchased and assembled from kits available at stores like Home Depot. Alternatively, they can be custom-built by the many closet companies out there.  Depending on the size of the closet, this portion of your project could range from $1000 to well over $10,000 for a high-end custom product. 
  • Lighting: Recessed lights are reasonably inexpensive and might cost between $100-200 per light installed.  Other lighting costs will depend on the fixtures you choose and ranges from very cheap to very expensive. 
  • Tile: Tile is expensive to install regardless of the style you choose because it’s labor-intensive.  You can save costs by selecting an inexpensive porcelain tile that comes in larger pieces. Larger tiles take less time to install.  Conversely, if you’re selecting an expensive time, especially in a small format, the costs will increase substantially.  The tile material cost can range from $1/sf on the low end to well over $10/sf for materials such as glass or marble. 
  • Bathroom fixtures: Items like faucets and shower hardware are available at a reasonable price at retailers like Lowes and usually come in basic styles and finishes like chrome.  For a higher-end look and style in finishes like gold or matte black, you will have to spend significantly more at places like Fergusson.
  • Bathroom cabinets & vanities: You can find bathroom vanities in standard sizes and styles at big retail home improvement stores or online. For a master bathroom, you will likely want a double vanity in a size between 60-72”, and this could range in price from $1000-2000 and usually include the vanity cabinet, countertop & sink.  Alternatively, if you need to create a custom vanity in a specific size or want additional bathroom cabinetry, it will require your contractor to have it custom-built.  You can also select a custom countertop to go with it and any number of sink options. In this case, you’re looking at spending at least $2000 and potentially up to $5000 or more.   

For a full breakdown of renovation costs that go into a bathroom, check out my blog about bathroom remodeling costs.

ROI and property value impact

Adding a master suite to your home not only enhances your living space but can also significantly impact the property’s value, making it a valuable investment. Research consistently shows that a well-designed and functional master suite contributes positively to a home’s resale value. The return on investment (ROI) for a master suite addition is often substantial, making it an attractive prospect for homeowners considering future property sales.

Buyers in today’s real estate market often prioritize homes with modern amenities, and a luxurious master suite fits this criterion. The additional square footage, especially one that includes a spacious bedroom, a well-appointed closet, and a stylish bathroom, can set your home apart and increase its market desirability. The perceived value of a thoughtfully constructed master suite aligns with the lifestyle expectations of many potential buyers.

Moreover, a master suite can cater to different demographics, appealing to families, empty nesters, or individuals seeking a comfortable and private retreat within the home. Analyzing local real estate trends and consulting with real estate professionals can provide insights into how a master suite aligns with regional market demands, ensuring a strategic approach to maximizing property value through this home improvement project.

What’s the process to create a master suite addition?

Master Bedroom Addition Monochrome

After doing some research on costs and determining how you plan to pay for the addition, the next steps are to reach out to both an architect and a contractor. It’s important to speak with both professionals upfront.

The architect can discuss with you the costs of the master bedroom addition plans (likely $8,000-$15,000), the process for plan submittal/approval by the city, the various city fees, and other considerations to create a functional floor plan.  The contractor is better suited to speak with you about the true cost of the project, the duration of construction, and other construction considerations you need to be aware of.

Building Plans and Approvals

You can expect that it might take 1-3 months for the architect to develop a full set of building plans and get it approved through the city building department. Once you start construction, it’s likely to take 3-4 months for completion. What’s nice about a master bedroom addition (versus a home remodel) is the work is all being done ‘outside’ of your existing living space, so you don’t need to deal with the dust or inconvenience of living without a kitchen or bathroom. That being said, there can still be a lot of noise coming from the work zone. If you’re looking for a bit more peace and quiet during the construction process, you may consider hiding noisy renovations with soundproof partitions.

Most contractors have relationships with an architect they can bring in to work on your plans, so you could start by meeting one or more contractors and their referred architects.  At the outset, a good contractor can give you a rough budget for the master bedroom addition based on their experience of doing similar projects in the past but will normally tell you that they can’t provide a fully accurate bid until your plans are complete.

Another reason to bring in a contractor early in the design process is their construction knowledge. Contractors can often look at a set of plans and value engineer the project by explaining to you where there are major expenses hidden. In some cases, those major items are an integral part of the project and cannot be changed (for example, a vaulted ceiling), but in other cases, a slight re-design of the space or materials of the project can save you a lot of money. Even architects are aware that this skill lies with the contractors because they are dealing with the costs of construction on a daily basis.

Building Permits

Once you have city-approved plans, but before you can start your project, you’ll need to secure a building permit. Often, the architect or the contractor will take care of getting the permit from the building department. You should ask for a copy of the permit before the job starts. Along with the permit, the building department will issue an inspection card that must remain at the project site. You should be able to see this card anytime you’d like, so ask the contractor where they will locate it for safekeeping.

The permit and inspection card initiates a process wherein a city inspector will visit the project at various stages to confirm your contractor’s work is being done up to the current code. Each time an inspector visits the project, they will either approve the current status, allowing the contractor to move on to the next step, or issue corrections that need to be addressed and ‘re-inspected’. It’s not uncommon for corrections to be issued by an inspector, but if it occurs too often, this can cause job delays. You can be present for an inspection to determine how the job is progressing and witness any issues that arise. Some inspectors can be ‘particular’ and make it difficult for contractors to stay on schedule, especially if the inspector regularly delays or reschedules their visits to the site.

Pro-Tip: Don’t forget about homeowners insurance. Before you begin your project, make sure to call your insurance agent. Ask about whether you have sufficient insurance to cover any issues during construction. Also, discuss the change in your policy that will be necessary when your additional living space is completed. Your agent should increase the total coverage on your home now that you’ve added space and your home is larger and more valuable.

How can I find a good master bedroom addition contractor?

Master Bedroom Addition White Bed

Finding a truly great, honest, and reliable contractor can be tricky. In Los Angeles County alone, there are over 20,000 licensed home contractors, so it’s not always easy to tell the good from the bad. The best way to find some good contractors is to ask friends, neighbors, or trusted colleagues for contractors they’ve used and liked. If you ask for recommendations on social media platforms, you should only trust recommendations from ‘real-life’ friends. People you don’t know personally are often biased (they’ll recommend their cousin, the contractor, etc).   

If you don’t get enough good recommendations from friends and relatives, consider using a service that performs intensive contractor screening and offers personalized introductions to good general contractors ( or similar). Don’t just pick a random home contractor from a flyer that came in your junk mail or from a nationwide contractor listing site.  See my blog about how to find and hire the best contractors.

Regardless of where you source your contractors, it’s important to do a thorough vetting process because the last thing you want in your life is a renovation nightmare. Although most people think they’ll be able to tell a good contractor from a bad contractor when they meet them, that’s probably not the case. Just because you have a ‘gut’ feeling that this person will do a good job, you shouldn’t always trust your gut…or at least do further research. Remember, the contractor or salesperson is trying to sell you on their company, so they’re on their best behavior.

Here are GreatBuildz, we have a 10-step vetting process that all contractors must pass before they can be part of our exclusive network. When you’re considering a contractor, you should also spend the time to vet them using as many of our steps as possible. Some of the most important screening tasks include:

  • Checking reviews online
  • Verifying they have an active GC license and insurance
  • Calling references
  • Interviewing the owner of the company to get all your questions answered.

A primary bedroom addition is not a small project. It will require numerous different trades, such as plumbing, electrical, flooring, drywall, etc. The best and really the only way to complete a large project like this is to hire a licensed, insured general contractor with a B-license from the CSLB. Make sure that any contractor you consider has a clean license and can provide you with current certificates for both General Liability and Worker’s Compensation insurance. At the CSLB website, it will tell you how long the contractor has been licensed. I believe it is always ideal to work with a company that has a reasonable amount of experience, so I suggest you consider choosing to meet with contractors who have been licensed for at least 3-5 years. 

Getting Room Addition Bids & Estimates

Firstly, it’s always advisable to get approximately three bids from multiple contractors when you’re considering a large project such as a room addition. You’re going to be spending hundreds of thousands of dollars; you should make sure that you’re paying an appropriate price. Take your time in getting multiple bids and comparing them carefully. Also, ideally, you would prepare some kind of scope of work checklist to provide to each contractor (or a set of plans for your project) so that each contractor’s bid is based on the same basic understanding of the project. If you only verbally explain your project to each contractor, it’s likely each one will have a slightly different understanding of the job.

Reviewing Bids

With regard to reviewing your bids, it’s very important to spend the time to confirm that every item you expect in the bid is actually included and accounted for. Each contractor’s bid format is different, so comparing these estimates is no small task. But, you must check each one and figure out which ones are missing which items until you get thorough estimates that include everything you expect and are completely comparable (apples-to-apples). Next, you need to determine exactly which materials are included in each bid and how these compare to all other bids. Materials are a large portion of the cost of the addition and can explain why one bid might be lower than another if they have excluded the cost of some materials.

It can be tempting to hire the lowest bidder but that can sometimes be a mistake. As discussed above, the low bidder may not be including the cost of some material and expects you to pay for this directly. Alternatively, a bid that’s significantly lower than all the others could be a sign that the contractor has underpriced the job and might need to charge you ‘extras’ during the project to make up for his/her losses. Similarly, an estimate that is significantly higher than the others might suggest that this contractor isn’t terribly interested in the work because they are already busy with other jobs. Bottom line: if you’re not getting bids that are somewhat consistent with each other (within 10-15% variance), you might consider getting bids from additional contractors.

Contingency Costs

Once you find the right contractor for you and select their bid, you should mentally prepare for a cost and time contingency of 10-20%. Let’s start with the cost contingency. Even if the bid is accurate and thorough, there will be items that come up during the project that were unforeseen. Material costs can change. Surprises come about during the project. An inspector can ask for additional work. You may request changes once you see the space in person. For these reasons and others, there are sure to be extra costs along the way.

Timing and Delays

With regard to timing and delays, it’s extremely likely that the project will take longer than expected. Similarly to the above, any unforeseen surprises or issues will take extra time to address. Any repairs requested by an inspector will take more time. Any changes requested by the homeowner will require extra labor and time to complete. Any material delivery delays will set you back as well. And you can expect bad weather to factor into the project timing. As you can see, there are many reasons that your project may not be done on time, so it’s best to plan for a timetable that’s longer than quoted by the contractor.


When it comes to planning and coordinating a master bedroom addition for your home, you shouldn’t have to go it alone – GreatBuildz can help simplify your renovation experience.


GreatBuildz is a free service that connects homeowners in Los Angeles, Orange County, Ventura & San Diego with reliable, thoroughly screened general contractors and provides project support from start to finish. Call now (818.317.3567) to chat with a real person about your next renovation project or visit our website for more information:

Hi, we're Paul and Jon - Co-Founders of GreatBuildz. We believe everyone deserves to find a great contractor, have a stress-free renovation, and enjoy their beautiful new space. There are so many contractors out there and it's often hard to tell the good from the bad... until it's too late. We started our company to help simplify your contractor search and help you have a stress-free renovation experience. We're always available to help, no matter where you are in the process. Click here to learn more about our story.

How can we help with your project?

Explore More Remodeling Topics

Remodeling Cost Guides

Cost Guides

design ideas

Design Ideas

Finding a Contractor

Finding a Contractor

Picking Materials

Selecting Materials

remodeling advice

Remodeling Advice