ADU costs
ADU construction cost guide for Del Mar & North County
Homeowners searching ADU cost in Del Mar are usually past the brochure stage. They want to know whether a backyard cottage is a mid–six-figure project or something else. This page is the honest version: typical ranges, what moves them, and why MA Properties will still visit the lot before writing a number that you can use.
Typical ranges, not a quote
A detached backyard ADU in Del Mar, Encinitas, Solana Beach, Cardiff, or Rancho Santa Fe is commonly a mid–six-figure project once foundation, utilities, envelope, and finishes are included. Conversions of an existing garage or space can land lower if the structure, setbacks, and utilities cooperate.
Online calculators that spit out a single dollars-per-square-foot figure ignore coastal overlay, hillside access, and whether the sewer already exists at the pad. Those are the items that move a Del Mar job more than the choice between two interior paint colors.
What actually drives cost
Site work and foundation: tight lots and slopes cost more to pad and drain than a flat inland yard.
Utilities: new water, sewer, and power runs can rival the finish budget on a small cottage.
Envelope: coastal-ready windows, weather barrier, and siding specified for salt air are not builder-grade vinyl.
Size and wet rooms: a studio with one bath is a different job from a two-bed unit with a kitchen.
Permits and design review: Coastal and association review add calendar time. Calendar time is not the same as construction labor, but it is still part of the real project cost.
How we estimate
Gustavo Mello visits the property. We 3D scan when it helps. You get a written estimate for a defined scope — not a website number dressed up as a contract. See our ADU construction page and the Del Mar backyard ADU project for how a build actually runs.