ADU Tiny House: Compact Living Spaces Types

What makes an accessory dwelling unit different from a small main house? Accessory dwelling units are secondary, tiny homes constructed on the same land as your existing main house. They provide homeowners or tenants with all the same amenities: a kitchen or kitchenette, a bathroom, a bedroom, and some living areas.

Both traditional homes and accessory dwelling units demonstrate a tendency for permanent dwelling in homes of compact size. Such homes require minimum maintenance, which leads to lower property taxes. They are cost-effective housing options, perfect for living minimally and wasting fewer resources.

Let’s delve into the distinctions between tiny homes and ADUs, their purpose, pros and cons, and explore how to efficiently optimize compact living space!

Accessory Dwelling Units vs. Tiny Houses

If you wonder what sets an ADU apart from a tiny home, here is a list of the characteristics by which these types of structures differ:

• Accessory House vs. Main Dwelling

A tiny home is a downsized, flexible primary residence. Some homeowners build tiny homes on wheels, while others opt for tiny houses on permanent foundations. In both cases, these homes are technically and legally primary dwellings. On the other hand, ADU homes are ancillary dwellings located in your backyard, where your main house already exists.

• Legal Differences

While an ADU project is subject to zoning requirements and building codes, tiny homes on wheels are considered recreational vehicles. RV codes foresee different permits and generally have construction, safety, and usage rules dissimilar to the ones applied to ADU homes.

• Construction Differences

Firstly, tiny houses on wheels are mobile, so they’re not attached to the foundation like ADUs. Secondly, ADU homes may be larger than tiny houses intended for moving. Also, ADUs are more durable, while tiny homes may utilize lighter materials, optimizing their weight for mobility.

• Differences in Utility Connections

Depending on the type of ADU, ADUs may have their utilities connected to the main house or have their own separate utilities, akin to traditional homes. Thus, ADU residents enjoy ordinary electricity, water supply, and sewerage systems. As for tiny houses, they often make use of independent energy sources (off-grid systems) like rainwater collection or solar power.

All in all, while having many things in common, tiny homes and accessory dwelling units focus on various aspects of a minimalist lifestyle.

ADU and Tiny Home: Pros and Cons Comparison

Both tiny homes and ADUs are efficient housing solutions that allow you to reduce your life costs, eliminate the burden of maintaining a large property, or declutter your environment of what no longer serves you.

However, they have different strong and weak points:

• Stability vs. Adaptability

ADU homes are permanent structures that create more living space on your property and increase its overall value. Thanks to their enduring nature, they can become a new home for your aging family members or a temporary home for tenants.

On the other hand, tiny homes with wheels concentrate on maneuverability and location adaptability, as their primary intention is to move around freely, changing scenery behind the window.

• Legal Considerations

Despite the intricate nature of zoning laws, ADUs provide legal certainty as they clearly belong to permanent residential constructions. As for tiny homes, the models with wheels count as recreational vehicles, which can complicate their long-term use as living spaces.

• Investment Potential

An ADU home is a substantial investment in your future because you can both use extra space for rent and increase property value, leading to higher sales revenues. Besides immediate rental income, you can also save on assisted living facilities if you use ADUs as granny flats for your elderly parents.

Yet, a tiny house offers a lower construction cost, alluring enthusiasts of a minimalist lifestyle. However, they don’t contribute to property value as significantly.

If everything you need for living is a small space, you may probably get interested not only in how ADUs and tiny homes are distinct from each other but also in how each option aligns with your needs.

Tiny House to ADU Home

Some homeowners in California wonder whether they can use a tiny house as an accessory dwelling unit. There’s no short answer to this question, as it heavily relies on key factors such as complying with local codes, zoning laws, and regulations.

So, what are the criteria for ADUs under California law? They encompass the following:

• The structure must permanently attach to a foundation;
• They must incorporate utilities that are mandatory for long-term human occupancy;
• They should have the same long-term resilience and durability standards as ADUs;
• They should align with conventional levels of comfortability and utility standards;
• They should correspond to the standards of safety, occupancy, and living standards.

Basically, these requirements mean that in order to qualify as an ADU, a tiny home should meet all the standards that local zoning laws establish for ADUs. It’s the same as a new ADU, which must have all amenities like a functional bathroom, kitchen, bedroom, and living space, as well as ventilation, heating, water supply, etc. Additionally, tiny homes also need to have an appropriate size and comply with height and setback requirements like any of the approved ADU models.

Tiny House Restrictions

Only some tiny houses can become an ADU due to foundation attachment requirements. This way, tiny homes on wheels are not suitable for long-term living. They fall under the concept of RV, and if there are no exemptions in zoning laws, they cannot be ADUs in most areas.

Accessory Dwelling Unit vs. Tiny Home Size

When you consider building backyard cottages, note that the parameters of ADUs and tiny homes differ. According to ADU ordinances and regulations, ADUs in California can be as small as 150 sq. ft. and as big as 1200 sq. ft. Typically, the smallest ADUs are internal ADUs within the footprint of the house (e.g., basement apartments), while the big ones serve as full-fledged residential dwellings suitable for permanent living.

In turn, tiny homes can occupy 100–400 sq. ft. This means that, in theory, they can be smaller ADUs that make the most of every inch of space. Quite frequently, they use multifunctional furniture and efficient storage solutions, allowing them to use the same space for different activities.

Nevertheless, due to their larger dimensions and enhanced flexibility of space, homeowners typically prefer ADUs. Larger in size, ADUs offer extra capacity for integrating the amenities and utilities commonly found in the main house. They’re more popular choices for rent, housing aging parents, or working remotely from backyard cottages.

ADU Property Value Effect

Since an accessory dwelling unit is part of real estate, it’s subject to property assessments, which grant homeowners a raise in the property’s value. The factors contributing to this raise are the added comfort of living and potential rental income.

In contrast, the presence of tiny homes on the lot does not affect property value if the tiny house is mobile and has no attachment to the foundation. Its non-permanent nature prevents homeowners from increasing the availability of the property despite the fact that homeowners could use them for rental income and continuous living.

When your property becomes worth more money, you can get better deals when borrowing money from banks. Also, you have the potential to sell the property at a higher price. These factors make some property owners decide in favor of ADUs or those tiny home designs that can become ADUs.

Frequently Asked Questions — FAQ

What does ADU stand for?

An ADU is an accessory dwelling unit, which is a residential building on your parcel. It’s typically smaller than your primary residence, but it can be big enough for comfortable long-term accommodation. In California, the biggest ADUs can reach as much as 1200 sq. ft., allowing for ample living space that is adept for your household needs.

Can a tiny house that is 400 sq. ft.be an ADU?

Sure, tiny homes that are 400 sq. ft. can meet the size requirements for ADUs in Sacramento, California. Eligible ADUs are tiny homes bound to the ground and falling into the range of 150 sq. ft. to 400 sq. ft. However, apart from their size, tiny homes must also adhere to other ADU rules and regulations.

Can I put a tiny house in my backyard in California?

Yes, it’s possible to put a tiny home in your backyard, especially if you intend to use it as an ADU. But even if you don’t, it’s still feasible. The only important issues you should pay attention to are the right use and compliance with the corresponding regulations. If it’s for personal use and meets regulations as a standalone structure within the property, a tiny home is completely fine.

What is the smallest ADU?

No matter the city rules, California state law stipulates that the minimum-sized ADU is 150 sq. ft. Moreover, the sleeping area cannot be smaller than 30 sq. ft., the food preparation area cannot be smaller than 50 sq. ft., and the bathroom area cannot be smaller than 70 sq. ft. However, ADUs that are so small may be less comfortable.

What are the pros and cons of a tiny home?

Such a construction as a tiny house is more affordable to build and maintain. With its help, your family can contribute to eco-friendly practices because it leaves a smaller carbon footprint and consumes fewer resources. It can also be rather flexible and perfectly cater to individual needs. Also, tiny homes have limited room, less convenient utilities, and complex regulations that present obstacles to their permanent usage.