Fullerton ADU design decisions that hold up in daily use.

01 · Exterior

Fit the property without pretending the buildings are identical.

Roof shape, wall material, windows, colors, exterior lighting, entries, and landscape transitions affect how the unit sits beside the main home.

The details also have construction consequences. Window sizes change headers, roof geometry changes drainage, and material transitions need durable flashing.

02 · Interior

Spend attention where the resident touches the home.

Kitchen workflow, bathroom clearances, storage, outlets, lighting controls, door swings, ventilation, and cleaning surfaces matter every day.

Use full-size samples where color or texture matters. Record model numbers and finishes so the bid, order, and installation match.

03 · Allowances

Turn finish language into a measurable budget.

“Standard finishes” is too vague. An allowance should say which products it covers, whether tax and delivery are included, and what happens when the owner selects above or below it.

Long-lead windows, cabinets, equipment, and specialty fixtures need decision dates tied to the construction schedule.

04 · Long-term use

Choose for maintenance as well as appearance.

Consider water exposure, sun, pets, rentals, aging in place, replaceable parts, cleaning, and access to service equipment.

A quieter, simpler, well-detailed material can be a better choice than a feature that adds complicated installation or upkeep.

What to review next

Follow the issue into the rest of the job.

Use these Fullerton guides to connect this decision with cost, permits, design, or field work.