ADU Construction

Why Build an ADU?

With flexible living options for family, guests, or multigenerational needs, our remodels and additions create spaces that adapt to the way you live. A self-contained dwelling can even provide rental income potential, while lifestyle upgrades such as a private office, gym, or studio bring everyday convenience and enjoyment. Every project is built with smart, durable construction that not only enhances your lifestyle today but also increases property value and delivers long-term return on investment.

Detached ADUs

Detached Accessory Dwelling Units—often called backyard homes or “granny flats”—are stand-alone living spaces built on the same property as your primary residence. These fully independent units include complete kitchens, bathrooms, bedrooms, and living areas, making them ideal for multi-generational living, rental income, guest accommodations, or private home offices. Because they are separate from the main house, detached ADUs offer maximum privacy and flexibility while enhancing your property’s value. With thoughtful design, they also promote indoor–outdoor living, often featuring patios, decks, or garden connections that create a seamless extension of your backyard. At De Mattei Construction, we specialize in designing and building high-quality detached ADUs that combine comfort, functionality, and lasting durability.

Attached ADUs

Attached Accessory Dwelling Units are connected to the primary residence but can be designed to function as completely independent living spaces, or completely cohesive with the home. These units share at least one wall with the main home yet often include private entrances, separate kitchens, bathrooms, and even outdoor patios for added convenience and privacy. Attached ADUs are an excellent choice for homeowners looking to maximize existing square footage while maintaining a sense of separation between households. They are ideal for multi-generational living, creating rental income opportunities, or offering guests a comfortable, self-contained place to stay. At De Mattei Construction, we build attached ADUs with the same craftsmanship, durability, and attention to detail as our detached backyard cottages—ensuring your new space is functional, beautiful, and adds long-term value to your property.

Garage Conversions

Garage conversions are one of the most efficient ways to add an Accessory Dwelling Unit (ADU) to your property. By repurposing an existing garage, homeowners can create a fully functional, code-compliant living space complete with proper insulation, egress, plumbing, and sound control. These conversions maximize the use of existing structures while transforming underutilized space into a private dwelling with a kitchen, bathroom, and comfortable living areas. Garage ADUs are ideal for generating rental income, creating independent quarters for family members, or building a versatile space such as a home office or guest suite. At De Mattei Construction, we specialize in high-quality garage conversions that meet all local building codes and deliver the same level of craftsmanship, comfort, and durability as a newly built unit—enhancing your property’s functionality and long-term value.

JADUs (Junior ADUs)

Junior Accessory Dwelling Units, or JADUs, are compact living spaces created within the existing footprint of your primary home. Often converted from a spare bedroom, bonus room, or unused area, these small but efficient units feature their own private entrance and an efficiency kitchen, making them fully functional while maintaining close proximity to the main house. JADUs are an excellent choice for homeowners who want to add flexible living space without the cost of new construction. They’re ideal for aging parents, young adults, caregivers, or even as rental opportunities for extra income. Because they utilize existing square footage, JADUs are often quicker to build and easier to permit than detached ADUs. At De Mattei Construction, we build JADUs with thoughtful layouts, modern finishes, and the same level of craftsmanship as larger units—ensuring your new space is comfortable, practical, and adds lasting value to your home.