One of the oldest neighborhoods near downtown, with tight lots and old detached garages, asks for compact backyard cottages and garage conversions that respect small setbacks.
The Lettered Streets, where the avenues run by letter just north and west of downtown, is one of the oldest residential neighborhoods in Bellingham. The homes here date back to the late 1800s and early 1900s, on tight lots that were platted long before anyone thought about a second unit. Many came with a small detached garage at the back. The ADU answer here is compact: a small backyard cottage or a garage conversion that works within the close setbacks these old lots leave you.
Small lots mean every foot of setback counts, and that is the first thing we map. The structures themselves are old, so a garage conversion here usually means insulating uninsulated walls, dealing with a slab that never had a vapor barrier, and upgrading a panel that cannot carry a modern kitchen. We design the unit to fit the lot, run a free feasibility check before any drawings, pull the permit with the City, and build to current energy code so it lasts through Bellingham winters.
ADU costs in Lettered Streets depend on the type. A ground-up detached backyard cottage runs $250,000 to $400,000 or more, a garage conversion runs $80,000 to $150,000, and a basement apartment conversion runs $90,000 to $180,000. The drivers are size, finish level, site access, and how far we run utilities to the unit. We give you a line-item number after a free site visit, so you know exactly what your project costs before you commit.
Do you build ADUs in Lettered Streets?
Yes. Lettered Streets is one of our core service areas, and we build backyard cottages, garage conversions, in-law suites, and basement apartments here. We start every project with a free feasibility check against your lot size, setbacks, and the City of Bellingham rules, so you know what your lot allows before you spend anything on design.
Who handles the permit for an ADU in Lettered Streets?
We do, start to finish. The Lettered Streets sit inside Bellingham city limits, so your ADU runs through the City, including the setback rules that matter most on these small lots. We handle the permit. We assemble the full permit package, manage the review including answering reviewer comments, and carry it through to an approved permit, then handle the inspections during the build.
Ready for a free Lettered Streets feasibility check?
Tell us about your lot and your goal. We'll reply within 15 minutes during business hours.