Master Bedroom Addition: Costs & Tips For 2023

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. Therefore, the master suite addition has been a common home improvement project for many local homeowners.    

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.


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

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 “dry” space (bedroom, closet) and “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 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 (400sf) 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-$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 2023 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.

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 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.

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.

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.

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 Workers Compensation insurance.

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.

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