In Seattle, more and more homeowners are putting their unused space to good use by building an ADU or DADU. This isn’t just a trend — it’s a smart way to increase your property value, generate rental income, or create private space for family. But what exactly are ADUs and DADUs — and how do they differ?

In recent years, building an ADU (Accessory Dwelling Unit) or DADU (Detached Accessory Dwelling Unit) in Seattle has become a smart way to increase property value, generate additional income, or create more living space for family.

Permits are official approvals issued by the city or county that give you the legal right to build, remodel, or install something on a property. The municipality checks whether your project meets building codes, zoning laws, safety regulations, and environmental standards. Simply put: without a permit, construction is not allowed. It's like a license to legally carry out the work.