If you’ve ever thought about building an ADU, you’ve probably had that moment where excitement meets confusion. You start with a simple idea, maybe a space for family, extra income, or just more room, and suddenly you’re looking at rules, permits, and technical terms. The good news is, once you understand the basics of ADU Requirements, everything starts to feel a lot more doable. California has made a real effort to open doors for homeowners. In most cases, once you submit your plans, cities are expected to respond within about 60 days. That kind of timeline brings a sense of structure to what can otherwise feel like an uncertain process.

When it comes to size, ADUs are meant to stay efficient but still comfortable. Smaller units like studios or one-bedroom layouts usually go up to around 850 square feet, while larger ones can reach up to 1,200. If you’re attaching the unit to your home, it’s often tied to the size of your existing space, typically capped at about half of it. Placement is also important, but it’s not as restrictive as many people assume. Standard ADU Requirements usually ask for about four feet of space from the side and rear property lines. Height limits depend on the type of unit, but there’s generally enough flexibility to create something that feels open and livable rather than boxed in.

Parking used to be a bigger concern, but that’s changed too. If your home is close to public transit or you’re converting an existing structure like a garage, you may not need to add parking at all. These small shifts in policy make a big difference in what’s actually possible. What surprises many homeowners is how flexible things have become overall. You can often build more than one unit, and in many cases, you’re not required to live on the property yourself. Still, local rules can vary, which is why it helps to look at both state and city guidelines before making decisions. West Coast Building & Design works closely with homeowners to translate these ADU Requirements into real, workable plans, especially across San Diego, California where every property has its own character.

If you’re thinking about building but don’t want to get lost in the details, starting with a clear conversation can make all the difference. Contact us today!