Design

What Is a Guest House?

A guest house provides accommodations for guests, family members, or renters. Build a guest house to meet your needs and budget with Cottage.
Updated June 13, 2020

If you pride yourself on being an amazing host for your guests, then you may want to consider building a guest house as a way to offer your guests a more private and enjoyable experience. With Cottage, a guest house in the form of an accessory dwelling unit (ADU) could be well within your reach.

Here’s what you need to know:

What Is a Guest House?

A guest house is a separate space from a main home that provides accommodations for guests, family members, or even renters. A guest house can range in size from a small 200 square foot studio with a kitchenette to a large two-bedroom, two-bathroom space with a full-sized kitchen, living room, and dining area.

How To Build a Guest House

Cottage is here to answer all of your questions about building a guest house. If any of your questions go unanswered, you can always reach out to the experts at Cottage for additional information.

Can You Build a Guest House on Your Property?

Before discussing all the intricacies involved in building a guest house, let’s first determine whether or not you can actually build a guest house on your property. Changes in regulations have made it easier than ever to add a guest house onto your property. However, these regulations do vary from county to county and from city to city.

Since these structures are extremely common in states like California, let’s cover some of the regulations in populous municipalities like Los Angeles, San Francisco, Oakland, and San Jose:

Los Angeles City

Lots zoned for single-family use with an existing dwelling are permitted to add one detached unit with up to 1,200 square feet. Detached units can have two stories but must be less than 25 feet tall in full. Detached units must be at least four feet away from the side and rear lot lines and at least ten feet away from any existing structures. One parking spot may be required.

Los Angeles County

Lots zoned for single-family use with an existing dwelling are permitted to add one detached unit with up to 1,200 square feet. Detached units can have two stories but must be less than 25 feet tall or less than 18 feet tall if within 200 feet of a Scenic Highway.

Detached units must be at least four feet away from side and rear lot lines and at least six feet away from any existing structures. One parking spot may be required.

San Francisco

Lots zoned for single-family use with an existing dwelling are permitted to add a one-bedroom guest house of up to 850 square feet or a two-bedroom guest house of up to 1,000 square feet. These units must be less than 16 feet tall and have minimum setbacks of four feet from the side and rear lot lines.

Oakland

Lots zoned for single-family use with an existing dwelling are permitted to add a one-bedroom guest house of up to 850 square feet or a two-bedroom guest house of up to 1,000 square feet. Detached units must be less than 16 feet tall and have minimum setbacks of four feet from the side and rear lot lines in addition to setbacks of six feet from any existing structures.

San Jose

Single-family lots of less than 9,000 square feet are able to add a detached unit of up to 1,000 square feet. Single-family lots of more than 9,000 square feet are able to add a detached unit of up to 1,200 square feet.

One-story units must be less than 18 feet tall; two-story units must be less than 24 feet tall. Detached units must be set back at least 45 feet from the front property line and a minimum of four feet from rear and side property lines.

What Are the Different Ways To Build a Guest House?

There are several different methods to choose from when building a guest house. For starters, you will have to choose between a prefabricated guest house, a modular guest house, and a custom guest house.

Here’s what you need to know about each of these building methods:

  • Prefabricated: A prefabricated unit in its entirety is fully completed and ready for installation. This means that the floor plan, features, and design are largely set. However, there is little room for personalization.
  • Modular: A modular unit comes in pieces that are then assembled on site. Again, since modular homes are pre-built in pieces, there’s not much room for changes or personalization.
  • Custom: A custom unit is designed and built to meet your specific needs. For example, if you need a guest house that’s ADA-accessible, you can custom-build one to meet these standards. Or, if you need a guest house that’s energy-efficient, you can choose to include a whole host of green and eco-friendly options. Many homeowners find that they are interested in customizing one or more elements of their guest house.

From there, you need to choose between a detached unit, an attached unit, and a conversion unit. Here’s what you need to know about each option for accessory dwelling units:

  • Detached: A detached unit involves building a structure that’s completely separate from the existing home. This option provides a high degree of privacy that’s ideal for guest houses.
  • Attached: An attached unit involves building a structure onto the existing home. This option eliminates any setback requirements that tend to limit the size of your guest house and allows you to take full advantage of your lot.
  • Conversion: A conversion unit involves taking an existing space in your home, like a basement or a garage, and converting it into a guest house by adding a bedroom, bathroom, kitchen, and living area.

How Much Does It Cost to Build a Guest House?

It’s important to understand the costs involved in building a guest house so that you can accurately calculate your potential return on investment. Building a guest house comes with both soft costs and hard costs that can be difficult to calculate without knowing where you’re building, how big you’re building, and the finishes of your building.

So let’s start by breaking down some of the soft costs:

Planning

Before you can start designing and building your guest house, you first need to determine if you can build, where you can build, and how big you can build. The best way to make these determinations is to schedule a site visit with an experienced builder. Some builders charge up to $1,000 for a site visit, while others, such as Cottage, do it for free.

Architectural Design

Based on the information gathered from the site visit, you can now move on to designing your guest house with the help of a qualified architectural designer. If you’re working independently with an architectural designer, you typically pay by the hour, with hourly rates reaching up to $250 depending on the experience and availability of the architectural designer. Throughout the course of your guest house project, this hourly rate can potentially add up to tens of thousands of dollars.

Consultants and Specialists

The architectural designer isn’t the only professional you need to work with on your guest house. You also need to work with a structural engineer, energy consultant, and site surveyor. All of these professionals charge for their services, with total costs ranging from $5,000 to $15,000 depending on the complexity of the project.

City Planning and Permitting

Once your designs are completed, they need to be reviewed and approved by the city before you can actually begin the construction process. You’re first charged planning and zoning review fees when you submit your plans to the city for review.

These fees vary by locality and can range in costs. Check with the Cottage team to learn more about the exact permitting fees for your municipality.

Examples of Hard Costs

Now, let’s move on to some of the hard costs:

  • Site preparation: In most cases, the guest house site will need to be prepared through grading to uniformly level the ground for the structure. Depending on the sloping of your lot, site preparation can cost up to $5,000.
  • Utility connections: Your guest house will need utility connections for electricity, plumbing, sewer, and gas. This process involves utility trenching and can come with costs of $10,000 or more.
  • Foundation: After that, it’s finally time to pour the concrete foundation for your guest house. Foundation costs can vary depending on the complexity of the project and ease of access to the construction location.
  • Construction: Now your guest house really starts to take shape during the construction phase of the project. This phase is also where you incur many of your costs to cover everything from framing and drywall, roofing and insulation, plumbing and electrical, and door and windows.
  • Fixtures and finishes: The finishing touches of your guest house are then added in the form of paint, flooring, cabinets, appliances, lighting, sinks, showers, toilets, and more. This is another expensive component of the process, as costs can range significantly depending on the level of fixtures and finishes you choose.

How Long Does It Take to Build a Guest House?

Understandably, you want to start benefiting from your guest house as soon as possible. So how long does it take to build a guest house from start to finish? It really depends on your location, your property, and your design.

There are four different phases involved in building an ADU guest house. Let’s break them down:

  • During the feasibility phase, you identify the right location on your lot for the guest house based on required setbacks and utility connections.
  • During the design phase, you design your guest house floor plan and choose your finishes. This phase typically takes between two and six weeks.
  • During the permitting phase, permits are submitted to the proper authorities for approval. This phase takes between ten and 16 weeks.
  • During the construction phase, your guest house vision finally becomes a reality. This phase takes four to six months.

When you add up these numbers, your guest house can be built in nine to 12 months.

How To Design a Functional Guest House

Designing a functional and beautiful guest house from scratch can be extremely challenging.

Here are some different components to consider adding to your space so that your guests will truly enjoy their stay:

  • Bedroom space that fits a queen-sized bed
  • Ample closet space for storage
  • Separate living and dining areas
  • Full-sized kitchen equipped with a refrigerator, stove, oven, dishwasher, and sink
  • Spacious bathroom
  • In-unit washer and dryer for laundry
  • Outdoor patio space

Coming up with a design that includes all of these elements on your own can be challenging, which is why Cottage has several pre-designed guest house floor plans to choose from:

  • If your guest house needs to have a tiny footprint, then the Madison is your best bet. This floor plan has one bedroom, one bathroom, and 364 square feet.
  • If you’re looking for a bit more space in your guest house but still want a minimalist feel, then the Nelson is an ideal choice. This floor plan has one bedroom, one bathroom, and 450 square feet.
  • If space isn’t an issue and you’re looking for a bigger space with plenty of room for living, dining, cooking, and sleeping, then you need to check out the Hopkins. This floor plan has one bedroom, one bathroom, and 732.5 square feet.
  • If you need to house more than one guest at a time, then the Travers is the perfect solution. This floor plan has two bedrooms, two bathrooms, and 990 square feet.

How To Choose a Builder for Your Guest House

As you can see, building a guest house isn’t necessarily a straightforward process. However, working with an experienced builder can help ensure that the process goes as smoothly as possible. Cottage has extensive experience in building guest houses, tiny homes, and granny flats.

Cottage streamlines the entire process with a team of in-house architects and designers in addition to an established network of vetted, licensed, and insured contractors. This means that designing a custom guest house using Cottage’s all-inclusive process often ends up costing less than going with a prefabricated or modular option.

Guests Welcome

Take your hosting abilities to the next level by building a separate guest house with Cottage. Reach out today for a free consultation and estimate with a Cottage ADU expert.

Sources:

California's New Accessory Dwelling Units Laws: What You Should Know | Forbes

Accessory Dwelling Units (ADUs) | California Department of Housing and Community Development

Accessory Dwelling Units | American Planning Association (APA)

Share

Get your free consultation and estimate today!