What Is an ADU? A Complete Guide to Accessory Dwelling Units
As cities and towns across the U.S. face growing housing demands and a need for more efficient use of space, Accessory Dwelling Units (ADUs) have emerged as a popular solution. ADUs provide flexible living arrangements, boost property value, and offer homeowners creative ways to make the most of their properties. But what exactly is an ADU, and why are so many people interested in building them? In this blog post, we'll dive deep into the world of ADUs, explaining what they are, the various types available, their benefits, and what you need to consider if you're thinking about adding one to your property.
What Is an ADU?
An Accessory Dwelling Unit (ADU) is a secondary residential structure that shares a lot with a primary residence. It’s a smaller, self-contained living space with its own entrance, kitchen, bathroom, and living area. ADUs can take several forms, such as garage conversions, basement apartments, backyard cottages, or standalone units built on the same property as the main house.
ADUs are sometimes referred to as granny flats, in-law suites, backyard cottages, or secondary suites. Regardless of the terminology, they serve the same purpose: providing an additional living space on a property that already has a primary home.
Types of ADUs
There are several types of ADUs, each designed to fit different property configurations, homeowner needs, and budget constraints. Below are the most common types:
1. Detached ADU (DADU) A detached ADU, also known as a DADU (Detached Accessory Dwelling Unit), is a separate building on the same lot as the primary residence. These ADUs are standalone structures, often located in the backyard. Detached ADUs are typically used as rental units, guest houses, or private spaces for family members. They offer more privacy since they aren’t attached to the main house, but they require enough space on the lot to construct a separate building.
2. Attached ADU Attached ADUs are physically connected to the primary residence, often added as an extension of the main home. They share one or more walls with the main house but have separate entrances and are fully self-contained. This option is ideal for homeowners who want an ADU but don't have space for a completely detached unit. It can be used for rental income, housing elderly family members, or creating a separate living space for adult children.
3. Garage Conversion ADU Many homeowners are converting existing garages into ADUs. A garage conversion can be an affordable and efficient way to create a separate living space without the need to build an entirely new structure. Since the basic framework already exists, a garage conversion typically costs less than a detached ADU. Garage ADUs are popular for rental properties, home offices, or guest suites.
4. Basement ADU If your home has an unfinished basement or a basement with underutilized space, converting it into an ADU is a smart way to maximize your home's potential. Basement ADUs are ideal for multi-generational living, as they provide a fully separate living area while keeping family members close by. They also offer rental income opportunities with minimal disruption to the main living space.
5. Internal ADU Internal ADUs are units that are built within the existing footprint of the home, such as in the attic or in a portion of the main house. These ADUs are smaller and require fewer alterations to the home, making them a less expensive option. Internal ADUs work well in homes where the existing layout can be easily reconfigured to create a self-contained living space.
The Benefits of ADUs
ADUs offer numerous advantages, making them an attractive option for homeowners. Below are some of the key benefits:
1. Increased Property Value One of the biggest advantages of building an ADU is the potential to increase your property’s value. An ADU provides additional living space, which is always attractive to potential buyers. Plus, the ability to rent out the unit can make the property more appealing to investors or buyers looking for additional income streams. In many markets, homes with ADUs can command higher resale prices than those without.
2. Rental Income For homeowners looking to generate extra income, ADUs are a great solution. You can rent out the unit to long-term tenants or use it as a vacation rental if zoning laws permit. In areas where housing demand is high, rental income from an ADU can be a significant financial boost and help offset the cost of the construction or mortgage payments.
3. Flexible Living Arrangements ADUs provide versatile living arrangements for families. For example, many homeowners build ADUs for elderly parents (hence the term "granny flat") so they can live independently but still be close to the family. ADUs can also provide housing for adult children who are attending college or starting their careers, allowing them to have their own space without leaving the family home.
4. Multi-Generational Living ADUs are perfect for multi-generational living, offering privacy and independence while keeping family members close. Whether it’s elderly parents, young adult children, or extended family, an ADU can provide a comfortable, independent living space that maintains familial connections.
5. Cost-Effective Housing Solutions As housing prices continue to rise in many cities, ADUs are becoming an affordable solution for both homeowners and tenants. For homeowners, building an ADU is often more cost-effective than purchasing a new property or expanding the main house. For tenants, ADUs offer more affordable rental options in residential neighborhoods.
6. Sustainable Living ADUs promote sustainability by maximizing land use and making better use of existing properties. Building an ADU requires fewer resources and materials than constructing a new house, making it a more eco-friendly option. Additionally, ADUs often have a smaller carbon footprint due to their size and can be designed to include energy-efficient features like solar panels, energy-efficient appliances, and sustainable building materials.
Considerations When Building an ADU
Before embarking on an ADU project, there are several factors homeowners should consider:
1. Zoning Laws and Regulations Zoning regulations for ADUs vary by city and county, so it's essential to check your local laws before starting any construction. In Gresham, Oregon, and other areas, there may be restrictions on the size, location, and use of ADUs. Permits and inspections will likely be required, so it’s crucial to work with a contractor who understands the local regulations.
2. Budget The cost of building an ADU can vary widely depending on the size, type, and materials used. It’s important to establish a clear budget and be prepared for unexpected expenses that may arise during construction. Garage conversions and internal ADUs tend to be less expensive, while detached ADUs can be more costly due to the need for a new structure and foundation.
3. Utilities and Infrastructure When building an ADU, you'll need to consider how utilities like water, electricity, and sewer will be connected to the unit. Depending on the layout of your property, this can add additional costs and complexity to the project. Working with an experienced contractor can help ensure that these connections are handled properly and efficiently.
ADUs are a versatile, cost-effective solution for homeowners looking to increase their property value, generate rental income, or accommodate multi-generational living. Whether you're converting a garage, building a detached unit, or adding an ADU within your home, these structures offer numerous benefits and flexible living arrangements. If you're considering adding an ADU to your property, it’s important to consult with professionals who can guide you through the process, from design to construction, while ensuring compliance with local regulations. At Modernize Home, we specialize in helping homeowners in Gresham, Oregon, design and build ADUs that enhance their properties and improve their quality of life.