ADU vs Tiny House: How Do They Compare?

An illustration of a tiny house next to an ADU

ADUs and Tiny Houses are bringing forward a new generation of housing.

Both offer an alternative way of living, but they are very different in how they’re classified. In this guide, we’ll explore what an ‘ADU’ and ‘Tiny House’ actually are, how they compare, and which could be more suited for you.

Let’s jump straight into it.

What are ADUs?

An Accessory Dwelling Unit (ADU) is a secondary housing unit on the same property as a primary residence. 

ADUs can be detached or attached to the main house, offering complete living facilities. 

ADUs can increase property value by up to 35% and provide flexible housing options:

Size and Structure 

ADUs typically range from 600 to 1,200 square feet (smaller variations are known as JADUs). They include a kitchen, bathroom, living area, and sometimes multiple bedrooms. 

They can be constructed as standalone units, garage conversions, or additions to the main house.

Utilities and Infrastructure

ADUs usually require connections to the primary residence’s utilities.

This includes water, electricity, and sewage systems, ensuring they meet residential living standards.

What is a Tiny House?

A Tiny House is a small, mobile, or stationary dwelling that emphasizes minimalistic living. 

Tiny Houses can range from 100 to 400 square feet and are often built on trailers for mobility. Imagine a portable, tiny living space that can be hauled around the states anywhere you like (assuming there is enough space).

Size and Structure

Tiny Houses are significantly smaller than ADUs, usually between 100 and 400 square feet – this is more comparable to a JADU than a regular ADU.

They maximize space with multifunctional furniture and open floor plans.

Mobility and Regulations

Tiny houses built on trailers are classified as recreational vehicles (RVs) and are subject to different regulations compared to traditional homes. 

Stationary Tiny Houses must comply with local building codes, similar to ADUs, but often face more stringent zoning laws.

How ADUs and Tiny Houses Compare

Now we’re on the same page about what each of these are, it’s time to see how they compare across several factors.

1. Size and Living Space

ADUs and Tiny Houses vary in size, with tiny houses typically being much smaller. 

  • ADUs: Typically offer more space, ranging from 600 to 1,200 square feet. They provide the amenities of a full-sized home, including separate bedrooms and full-sized kitchens and bathrooms.
  • Tiny Houses: These are usually much smaller, usually 100 to 400 square feet. They focus on maximizing space efficiency and often feature lofted sleeping areas and compact kitchen and bathroom facilities.

Junior Accessory Dwelling Units (JADUs), a variation of the classic ADU, are more comparable to Tiny Houses.

2. Construction and Cost

ADUs and Tiny Houses are comparable in construction cost on the lower end, but the upper limit for ADUs is much higher due to the potential size difference available for these types of buildings.

  • ADUs: Construction costs for ADUs are higher due to their size and the need to comply with residential building codes. The typical cost is anywhere from $20,000 to $150,000, and this varies depending on size, construction time, and more.
  • Tiny Houses: These are usually more affordable, with costs typically ranging from $30,000 to $80,000. These lower costs are due to their smaller size and simpler construction requirements.

There is also the design cost to consider as well.

Creating architectural and site plans is not cheap, and more space = more cost. Presite offers an easy solution to the site planning aspect, but the cost still needs to be considered for the budget.

3. Zoning and Regulations

With any unique type of property or dwelling, there are always going to be lots of zoning and regulations to get through before you can think about starting construction, and the same can be said for ADUs and Tiny Houses.

  • ADUs: Must comply with local zoning laws and building codes. This includes obtaining permits and adhering to size, occupancy, and utility connections regulations. Cities like Seattle and Portland have revised zoning regulations to facilitate DADU construction.
  • Tiny Houses: Face unique regulatory challenges. Mobile Tiny Houses are classified as RVs and must comply with RV standards, while stationary Tiny Houses must meet local building codes and often face stricter zoning laws.

The landscape for zoning and regulations for both is very complex, and you should always seek professional help in the construction of either type of property.

4. Usage and Flexibility

A key difference between Tiny Houses and ADUs is how they are commonly used.

ADUs are more suitable for long-term accommodation, so they’re often built to house members of the family or friends or even as rental units.

Tiny Houses work better as temporary housing or as a downsizing option. Lots of people also love them for the minimalist approach and living off grid.

Financing Options

ADUs and Tiny Homes differ in finance options.

ADUs

ADUs are more accessible thanks to government schemes and more widespread support for their construction:

  • Home Equity Loans: Homeowners can use the equity in their property to finance ADU construction, and these loans tend to be much more affordable than a personal loan, which may be required for a Tiny House.
  • Government Incentives: Some local governments offer grants and incentives to encourage ADU development. For example, the City of Portland provides financial assistance to offset construction costs, as well as pre-approved plans and more.

Tiny Houses

Obtaining financing for Tiny Houses can be more difficult, but there are still several options:

  • Personal Loans: Given their lower cost, Tiny Houses can often be financed with personal loans. Lenders like LightStream and SoFi offer loans specifically for tiny house purchases.
  • RV Loans: For mobile Tiny Houses, RV loans are a common financing option. These loans have flexible terms and can be tailored to the buyer’s needs.

The obvious benefit here is that most Tiny House projects can be approached with a personal budget, especially if there isn’t a rush on the timeframe.

Environmental Impact

Both ADUs and Tiny Houses offer environmental benefits by promoting efficient land use and reducing the ecological footprint of housing.

  • ADUs: Help increase housing density without expanding urban sprawl. A study by the Environmental Protection Agency highlights that ADUs can reduce per capita energy consumption and greenhouse gas emissions (EPA Study).
  • Tiny Houses: Emphasize sustainability and resource efficiency. The small size of Tiny Houses leads to lower energy consumption and less waste production, and has been shown to reduce energy consumption by up to 45%.

ADUs and Tiny Houses both offer innovative housing solutions but differ in size, cost, and regulatory requirements. 

ADUs provide more space and amenities, making them suitable for long-term living, while Tiny Houses offer affordability and mobility, appealing to those seeking a minimalist lifestyle. 

Understanding these distinctions helps homeowners and buyers make informed decisions based on their specific needs.

Ready to create exceptional
site plans?