ADU in Bloomington, CA
Junior ADU & Interior Conversion in Bloomington typically runs $85,000-$165,000 all-in, drawings through final inspection, while ADU Site Prep & Utilities adds $25,000-$75,000 depending on whether we’re trenching across a half-acre Rural Living lot or upgrading a 1960s electrical panel. We’re Ellery ADU Studio, a design-build practice that handles the permit set, the construction, and the final inspection under one written contract - no designer-builder blame gap. Call (909) 637-3715 to schedule your free estimate.
Why Bloomington Homes Are Different
Bloomington is unincorporated San Bernardino County, not a city, so every ADU permit routes through the County’s Land Use Services Department in San Bernardino - a critical distinction that catches contractors from neighboring Fontana or Rialto off guard. The Rural Living zone covers much of Bloomington, with half-acre to two-acre lots historically tied to horse-keeping and small agriculture. That generous space means detached ADUs up to 1,200 square feet often fit easily, but existing outbuildings, stables, or tack rooms may carry agricultural-use permits that require reclassification before residential conversion.
The housing stock is predominantly single-story ranch homes built from the 1950s through the 1980s. Summer highs routinely top 105°F with intense solar gain on flat rooflines, so undersized cooling systems fail fast in backyard units with limited shade. Any detached ADU here needs a properly sized mini-split and a radiant barrier or spray-foam roof deck - non-negotiable in this climate.
Our Main Bloomington Services
Bloomington homeowners call us most often for these three services, each with its own dedicated page:
ADU Design & Permitting in Bloomington
We produce the full permit set - site plan, floor plans, elevations, structural calcs, Title 24 energy compliance - and shepherd it through San Bernardino County Land Use Services. Because Bloomington is unincorporated, we file directly with the County rather than navigating a city building department, a process we’ve refined across hundreds of Inland Empire projects. ADU Design & Permitting in Bloomington
Garage Conversion ADU in Bloomington
Many Bloomington garages sit on 4-inch slabs with block walls that convert well, but we first verify whether any existing structure was permitted as agricultural accessory - reclassification triggers a separate County review step. We handle that verification, the structural assessment, and the full build under one contract. Garage Conversion ADU in Bloomington
New Detached ADU in Bloomington
The oversized Rural Living lots in Bloomington allow detached ADUs that simply wouldn’t fit on Fontana or Rialto’s standard suburban parcels. We design for the 105°F summer reality from day one - proper mini-split sizing, radiant barriers, and orientation that minimizes western exposure. New Detached ADU in Bloomington
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Before
AfterJunior ADU & Interior Conversion in Bloomington
Bloomington’s 1950s-1980s ranch homes offer prime candidates for Junior ADU & Interior Conversion: large floor plates, minimal stairs, and existing utility access that keeps tie-in costs lower than new detached construction. The interior approach also sidesteps the agricultural-reclassification hurdle that can delay outbuilding conversions in Rural Living zones. We handle the full design-build sequence - measured drawings, permit set, construction, final inspection - at one written price under Haven Standard Clause 1.
Room-to-ADU Conversion
Signs you need it
You have a 300-500 square foot bedroom suite, den, or former mother-in-law quarter with its own exterior door and window egress that could become a self-contained rental unit.
What it costs in Bloomington
Room-to-ADU conversions in Bloomington typically run $85,000-$125,000 all-in, including the separate kitchenette, bathroom, and utility meter split.
How we do it
We verify ceiling height meets 7’6″ minimum, design the kitchenette and wet wall layout, produce the County permit set, then build to the drawings with documented photo records on every visit.
Interior JADU
Signs you need it
You want rental income or family housing without exterior construction, and your home has a contiguous bedroom-bathroom area that shares a wall with existing utilities.
What it costs in Bloomington
Interior JADUs in Bloomington typically run $65,000-$95,000, lower than full ADUs because they use the primary home’s systems with a small kitchenette added.
How we do it
We confirm the owner-occupancy requirement, design the efficient kitchenette and separate entrance, pull the County permit, and build to the signed scope with no change orders.
What Junior ADU & Interior Conversion Costs in Bloomington
| Item | Typical range in Bloomington |
|---|---|
| Room-to-ADU conversion (all-in) | $85,000 - $125,000 |
| Interior JADU (all-in) | $65,000 - $95,000 |
| Above-garage ADU (all-in) | $110,000 - $165,000 |
Does a JADU require separate utilities in Bloomington?
No - a Junior ADU shares water, gas, and electric with the primary residence per state law, though we install a sub-meter for rental tracking if desired. Call (909) 637-3715 for an exact quote - estimates are free.
Can I convert my Bloomington basement to an ADU?
Basement ADUs are rare here because most Bloomington ranch homes lack basements, but where they exist we verify 7’6″ ceiling height, emergency egress windows, and moisture mitigation before designing. Call (909) 637-3715 for an exact quote - estimates are free.
ADU Site Prep & Utilities in Bloomington
Bloomington’s Rural Living lots and 1950s-1980s ranch infrastructure create specific site prep challenges: long utility runs across half-acre parcels, aging electrical panels never sized for a second dwelling, and septic systems that may need expansion for an additional bedroom count. We handle these prerequisites as a defined scope item under ADU Site Prep & Utilities, with a written price before breaking ground and documented photo records of every trench and connection.
Electrical Panel Upgrade
Signs you need it
Your existing panel is 100 amps or has no open breaker spaces, which cannot support an ADU’s independent load.
What it costs in Bloomington
Electrical panel upgrades in Bloomington typically run $4,500-$8,500 including the new 200-amp service, permit, and SCE coordination.
How we do it
We assess your current load calc, specify the new panel and conduit run, pull the County electrical permit, and coordinate with Southern California Edison for the service upgrade.
Plumbing Lateral
Signs you need it
Your ADU location is more than 75 feet from the main sewer or water line, or the existing lateral is galvanized steel or clay bell-and-spigot.
What it costs in Bloomington
Plumbing lateral extensions in Bloomington typically run $8,000-$18,000 depending on trench length, asphalt or concrete restoration, and whether we hit granite caprock.
How we do it
We locate the existing lateral with camera inspection, design the new route across your lot, trench with proper bedding and slope, and pressure-test before backfill.
What ADU Site Prep & Utilities Costs in Bloomington
| Item | Typical range in Bloomington |
|---|---|
| Electrical panel upgrade | $4,500 - $8,500 |
| Plumbing lateral extension | $8,000 - $18,000 |
| Foundation and grading (detached ADU) | $15,000 - $35,000 |
Will SCE require a new service drop for my Bloomington ADU?
Often yes for detached ADUs - Southern California Edison typically requires a separate service lateral and meter, which we coordinate as part of the electrical scope. Call (909) 637-3715 for an exact quote - estimates are free.
How long does site prep take before ADU construction starts?
Utility work typically runs 3-6 weeks in Bloomington, longer if SCE or the County requires engineered plans for the service upgrade or septic expansion. Call (909) 637-3715 for an exact quote - estimates are free.
Brands We Service in Bloomington
We specify and coordinate prefab and modular systems from Cover, Dvele, and Mighty Buildings within our single-contract design-build model, handling factory liaison, transport, crane set, and finish-out. Local parts stocking and factory-direct support keep turnaround predictable. See our brands for full specifications.
Pricing for ADU in Bloomington, CA
| Service | Typical range in Bloomington |
|---|---|
| Room-to-ADU conversion (all-in) | $85,000 - $125,000 |
| Interior JADU (all-in) | $65,000 - $95,000 |
| Above-garage ADU (all-in) | $110,000 - $165,000 |
| Electrical panel upgrade | $4,500 - $8,500 |
| Plumbing lateral extension | $8,000 - $18,000 |
| Foundation and grading (detached) | $15,000 - $35,000 |
| Gas line extension | $3,500 - $7,500 |
| Landscaping and hardscape restoration | $5,000 - $15,000 |
Price drivers in Bloomington include long utility trenches across Rural Living lots, agricultural-structure reclassification fees, and the mandatory cooling upgrades for 105°F summers. Under Haven Standard Clause 1, your written price is locked at signing - no surprises, no change orders.
Neighborhoods We Serve in Bloomington
We work across Bloomington’s unincorporated areas, from the older ranch neighborhoods near Valley Boulevard to the larger Rural Living parcels toward the Jurupa Hills. Dispatch and scheduling are coordinated from our Inland Empire office; crews serve Bloomington locally with same-day response for active projects.
- Valley Boulevard corridor
- Jurupa Hills fringe
- Rural Living zone (half-acre to two-acre parcels)
- Cedar Avenue vicinity
- Bloomington Ranch area
Service Area - Cities Near Bloomington
Our crews work throughout the western Inland Empire, with active projects in Rialto, CA, Fontana, CA, Riverside, CA, and Mira Loma, CA. Each city has its own permit pathway - incorporated cities with their own building departments, unincorporated areas through San Bernardino County - and we file correctly the first time.
Serving Bloomington, CA - Our Local Coverage Area
We’re based in the Bloomington area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU in Bloomington
County - Bloomington is unincorporated, so San Bernardino County Land Use Services handles all ADU permits. This differs from neighboring Rialto, Fontana, and Colton, which have their own building departments with different submittal requirements and review timelines.
Yes, Rural Living zones allow ADUs with generous setbacks, but existing stables or tack rooms permitted as agricultural accessories must be reclassified to residential use before conversion - a separate County review step that adds weeks but is manageable with proper documentation.
We schedule concrete pours and roofing for morning hours in July and August, specify light-colored roofing with radiant barriers, and size mini-splits at 20% above standard Manual J calculations - undersized systems fail within the first summer in Bloomington’s 105°F peak days.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Bloomington Customers Say
"Garage conversion finished on the drawings and close to the schedule. They were honest that the sewer connection was the unknown, and it was."
- Arjun D."They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T."The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N.