Breaking Down the Costs: Building a Granny Flat in San Diego

Granny Flat in San Diego

What are the costs of building a granny flat in San Diego? House to Home, your experienced house builders have all the answers. 

If you’ve ever considered adding a granny flat to your home in San Diego, the question of granny flat prices and the cost to build a granny flat would have definitely come up. Here at House to Home, we’re a design-build firm in the San Diego area specializing in granny flats, more commonly known as accessory dwelling units (ADU) and design build projects. We offer a range of tailored services to fit our clients and budgets.

However, the question of budget and how much elements cost is something we get asked about all the time. We understand that when you make an investment with us, you want to be sure where the money is going. Our team is proud to be transparent and open about the costs of building a granny flat. That’s why we’re dedicating today’s blog to be all about what goes into our process and the final investment that you can expect to make.

Benefits of Building a Granny Flat in the San Diego Area

Before we look at the process, we have to discuss the benefits of building a granny flat in the San Diego area. No matter your purpose for building a granny flat, a huge range of benefits come with it. Listed below are just a few.

Increase the Value of Your Home

When you’re investing in further improving your home, you’re immediately increasing its value. In the future, if you’re ever looking to sell, you’ll open up your home to the additional market of buyers. Having a high-quality granny flat with additional bedrooms and bathrooms drastically increases the value of your home.

Rent Out and Create Additional Income

Ever since the pandemic, we’ve seen a huge rise in Airbnbs and people taking an interest in renting out a portion of their homes to create additional income. While a large portion of our clients build a granny flat for the purpose of family members, using the space for additional income is great, particularly in the area of San Diego.

Maximize Liveable Space

Although we love the outdoors in San Diego, creating and utilizing your extra living space is great for using the space throughout the entire year. Adding a granny flat to your backyard or property allows your family and friends to take advantage of the livable space. This allows everyone to spread out while still remaining close together.

Cost-Effective Building Solution

If you’re looking into expanding your living space or home, you’ll know it’s an investment. While the investment is worth it, it’s one that can be expensive and, for some people, out of their budget. For those that still need the extension of space, a granny flat is a great cost-effective building solution.

When you build a granny flat, you’re still creating additional livable space for family or friends but don’t need to have construction happening in the home to achieve this. This is truly a great alternative and can give everyone the best of both worlds.

House to Home Does It All for You

While a granny flat can seem like a smaller build and one that may be achievable as a DIY project, there are plenty of things that experienced builders will be best to help with along the way. When you choose to work with a company like House to Home, our team is highly experienced, so you have the peace of mind that your granny flat will be built correctly and at its highest quality. We also work with a customer centric foundation, so you’re our main priority throughout the project, ensuring that you enjoy the process as much as we enjoy building it.

Types of Granny Flats in the San Diego Area

Depending on your needs, budget and the project’s purpose, our team can best suggest a granny flat that will work best for you in the San Diego area. With the recent introduction of the laws in 2020, it’s now easier and more accessible to build and create a granny flat. House to Home currently offers all types of granny flats but here are a few common options we regularly build for our clients.

1 Bedroom/ 1 Bathroom

The smaller of the two granny flats is the one-bedroom, one-bathroom granny flat. These are great for clients needing the extra space to branch out. Particularly to be used as an office when working from home. Although this is the smaller floor plan out of the two, this sized granny flat still gives you all of the same benefits and can be designed to transform your backyard.

2 Bedroom/ 2 Bathroom

The larger granny flat out of the two designs we are discussing is a two-bedroom and two-bathroom granny flat. These are ideal for those families or individuals looking to rent out the space and create a passive income. In addition, due to the larger nature, the design possibilities are greater, allowing you to affordably incorporate art, along with introducing other key design features.


Depending on your budget and choice of a granny flat in the San Diego area, you’re likely looking at an investment between $100k to $300k but could even be higher depending on the quality and choice of materials. This cost varies due to a range of factors. We’ve listed some of these below.

  • Site costs, what needs to be done prior to building
  • Electrical work
  • Plumbing
  • Design features and fit-outs
  • Building materials

While this is not an all-inclusive list, all of these factors and more will influence the final cost of your granny flat. In addition to this, your design choices will have a huge impact on cost. When we go through our design process with you, we’ll offer choices for each budget and inform you of what will be the best decision for your project in particular.

Our Design Process

Although each process is different for design-build firms in San Diego, we have a structured process that allows us to make the most out of our time working together and ensures that everything is streamlined. This not only makes it easy and stress-free for you but also provides a relaxed and enjoyable experience when building a granny flat. This is an insight into our design process.

Site Feasibility and Pre-Design

First, we begin our process by looking at site feasibility and pre-design. This is our initial consultation. We review the existing land and the utility structure and chat with you about what exactly you are looking for. We also talk to you about the budget, how much you’re happy spending and what your project could look like in terms of how much you’d feel comfortable investing.

Design Concept Process

From there, we then move into the design concept process. This is where we’ll streamline the design, ensuring that you’re comfortable and excited about what is going to be created. We go through all of the material and product selection options. This greatly impacts your budget, so we’ll guide you through this to ensure you’re not going above your budget. You’ll also be provided with a floor plan and full-scaled 3-D color renderings.

Design Presentation and Spec Book

Once we’ve finalized the design concept process, we present you with the final design and spec book. Here, we’ll finalize your floor plan and material selection and create a final spec book. A spec book contains all of the models and finishes to provide you with detailed information on your project.


Once all designs and plans have been signed off, we then move into the pre-construction stage. This is where our team will purchase all materials needed. Depending on where you’re located within the San Diego area, we’ll talk with local councils and authorities to gain approval for your granny flat.


Providing quality control at each phase during the project, you’ll be provided with continuous updates and communication from project managers as each phase of the project unfolds. To ensure the project is streamlined and all parties involved understand what they need to complete, our team will have weekly meetings to maintain synchronicity.


Focusing on client satisfaction throughout the entire project, once we’ve completed construction, you’ll receive an owner’s manual, along with a final walk-through to ensure that you’re happy with the end result. We also set owners up with a warranty phase and provide several lines of communication so that you can chat with our team about any remaining questions.

Final Thoughts

Building a granny flat is an excellent decision for you, your family and as an investment. House to Home is here to support you every step of the way, no matter your budget. Our team and company work on a customer-centric foundation. We pride ourselves on giving all customers incredible customer service. We’re open about projects, transparent about budgets and communicate with you throughout the entirety of the project.

If you’re considering building a granny flat in San Diego or are curious about specific granny flat plans and prices, then get in touch with our team. We’ll discuss what we can offer and how we tailor our services to you.