Quick answer: A ductless mini-split is the best HVAC solution for almost every ADU in Los Angeles — no ductwork needed, installs in 1–2 days, and costs $3,500–$7,500 for a single-zone system. APLA Construction (CA Lic #1136359) designs and installs the complete HVAC package on every ADU we build.
An ADU’s HVAC system is easy to underplan and expensive to get wrong. Because most ADUs are detached from the main house with no access to existing ductwork, the HVAC decision isn’t “which brand” — it’s “ducted or ductless,” and for the vast majority of LA ADUs, the answer is ductless.
| ADU Size | Recommended System | Typical Cost |
| Studio / JADU (up to 500 sq ft) | Single-zone mini-split | $3,500–$5,500 |
| 1-bedroom (500–750 sq ft) | Single-zone mini-split | $4,500–$7,500 |
| 2-bedroom (750–1,200 sq ft) | Multi-zone mini-split (2 heads) | $8,500–$14,000 |
Oversizing is a common and costly mistake — an oversized mini-split short-cycles, wastes energy, and does a worse job of dehumidifying than a correctly sized one. We size based on your ADU’s actual square footage, insulation, and window exposure, not a rule of thumb.
A mini-split needs its own dedicated circuit, typically 220–240V for the outdoor compressor. This is normally included as part of the ADU’s subpanel design — see our electrical panel upgrade guide for what a full ADU electrical package includes.
Yes, in many cases. California Energy Commission-approved heat pump mini-splits can qualify for state and utility rebates of $1,000–$3,000, and installing a heat pump instead of a separate AC-plus-furnace combo aligns with the state’s electrification direction under Title 24. See our Title 24 compliance guide for how this affects ADU plan check.
Yes. Mini-split installation requires a mechanical permit, and the electrical circuit requires an electrical permit. Both are typically pulled as part of the ADU’s overall building permit package, not separately. APLA handles all required permitting.
For a studio or 1-bedroom open-plan ADU, yes — a single indoor head sized correctly for the square footage handles the whole unit. Larger or multi-room ADUs benefit from a multi-zone system so each room has independent temperature control.
No. Modern mini-split indoor units run at roughly 19–30 decibels on low-to-medium settings — quieter than a normal conversation. Outdoor compressors are placed away from bedroom windows where possible.
A mini-split is a permanent, code-compliant installation that provides both heating and cooling, doesn’t block a window, and qualifies for rebates. A window unit is cooling-only, less efficient, and generally not acceptable for a permitted ADU under current energy code.
Yes. HVAC is designed and priced as part of the full ADU scope on every project — see our complete ADU cost guide for how it fits into overall budget.
APLA Construction (CA Lic #1136359) designs and installs the complete HVAC package on every ADU we build across Greater Los Angeles — sized right the first time.
Call: (818) 818-4419
Email: info@aplaconstruction.com
CA General Contractor License #1136359