What does getPermit actually do?

getPermit reads your job details and tells you what a California city expects before you file: which permits the work triggers, the documents and plans you'll need, the fees to budget for, and the common reasons applications in that jurisdiction get bounced back. It produces a clear checklist you can act on. It does not submit to the city for you — you (or your permit person) stay in control of what gets filed.

Is there a human involved, or is it just AI?

Both. The AI does the research and drafts the assessment and checklist; an experienced permit coordinator reviews and approves it before it's treated as authoritative. The human check is the point — it's how we keep it trustworthy in a process where a wrong filing has real consequences.

Which cities do you cover?

We're starting deep in California rather than shallow everywhere. For a city we haven't fully mapped yet, we'll give you accurate general California guidance and point you to that city's official building department — and you can join the waitlist to be notified when we cover it in depth. We will not invent city-specific fees or timelines we haven't verified.

Solo electricians, plumbers, and HVAC contractors, and small general contractors who don't have a dedicated permit department and lose billable hours to permit admin.

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We're onboarding a first set of California contractors. Join the waitlist with your city and trade so we can prioritize the jurisdictions our early users actually work in.

Duct replacement permits in Mountain View, CA

General California guidance last updated September 23, 2026 · Mountain View data fully re-verified August 10, 2026

What HVAC contractors need to know about pulling a duct replacement permit in Mountain View (Santa Clara County).

Short answer

In California, replacing or extending ductwork requires a mechanical permit, and the Energy Code (Title 24, Part 6) treats it as an alteration: replacing a duct system entirely — or adding/replacing more than about 40 linear feet in unconditioned space — generally triggers duct sealing with third-party HERS leakage testing. Ducts must meet the insulation R-value for the climate zone. A C-20 (HVAC) licensed contractor generally pulls it.

Mountain View accepts submittal through the ePermitsMV (Avolve) and has adopted the 2025 California Building Standards Code (Title 24, with Mountain View amendments). Fee details and sources are below.

Mountain View permit data

Sourced from public City of Mountain View documents — every field carries the source URL and verification date.

Permit portal

ePermitsMV (Avolve)

verified Aug 10, 2026 · source · "The permit process is handled exclusively on this platform" — city pages link ePermitsMV to the Avolve-hosted portal; account sign-in is required to apply

Adopted code edition

2025 California Building Standards Code (Title 24, with Mountain View amendments)

verified Aug 10, 2026 · source · Effective January 1, 2026, all Building and Fire permit applications must comply with the 2025 California Building Standards Code and certified standards, adopted by reference with local amendments

Fee schedule

Building Permit Fees — effective August 22, 2026 (valuation-based fee table)

verified Sep 13, 2026 · source · The city applies a 5% technology fee on the total permit cost of each building and fire permit issued

City of Mountain View Community Development — Building Division →All verified Mountain View data →

The general picture in California

Ductwork replacement is permitted mechanical work across California, and the review is mostly an Energy Code review. Title 24, Part 6 treats duct work as an alteration: replace the system, or add or replace more than about 40 linear feet in unconditioned space, and duct sealing with third-party HERS leakage verification generally follows — documented on a CF1R-ALT and registered before final. The materials layer is simple but strictly checked: insulation at the climate zone's required R-value (R-6 or R-8 in most cases), joints sealed with mastic or listed UL 181 tape — never cloth-backed duct tape — and flex duct supported so it isn't kinked or compressed. Because the HERS rater is independent, the schedule needs their test and registration between substantial completion and final inspection. Fees, forms, and inspection scheduling are set per city — confirm with the local building department.

For deeper background that isn't Mountain View-specific, see the statewide duct replacement guide.

Typically needs a permit

Duct replacement itself triggers a permit in nearly every California jurisdiction, Mountain View included. Mountain View-specific variations are confirmed with the issuing department above.

Usually doesn't (general norm)

Maintenance sealing of accessible duct joints (verify locally)
Replacing registers and grilles
Repairing insulation on existing ducts

Documents & plans generally required

Mechanical permit application
Contractor license and city business registration
Duct layout with sizes, materials, and the equipment served
Insulation R-value spec meeting the climate zone (commonly R-6 or R-8)
Energy-compliance form (CF1R-ALT) and HERS registration where testing is triggered
Support/hanger spacing and connection method for flex duct

Common reasons duct replacement applications get bounced

Code-rooted patterns across California — not a Mountain View-specific rejection rate.

Missing CF1R-ALT or HERS registration when the scope triggers duct testing
Insulation R-value below the climate-zone requirement
Cloth-backed duct tape as the sealing method — sealing must be mastic or listed (UL 181) tape
Leakage over the allowed percentage at the HERS test
Flex duct unsupported, kinked, or compressed to the point of choking airflow
Scope written as a 'repair' when most of the system is being replaced

The inspection sequence

A typical order — the number of stops and exact sequence vary by jurisdiction and scope.

1Rough inspection where ducts are concealed in framing before cover
2Final inspection with the system complete and the HERS duct-leakage results registered where required

Licensing — who can pull it

Duct replacement in California is generally C-20 (HVAC) licensed work; a B (General Building) contractor may pull within a larger remodel under CSLB rules. The HERS duct test is performed by an independent third-party rater, not the installing contractor.

Other verified Mountain View notes

Building counter: City Hall, First Floor, 500 Castro Street, Mountain View, CA 94041; 650-903-6313; public counter hours Monday–Friday 8 AM–4 PM.
verified Aug 10, 2026 · source
All building permits must be signed by a California licensed contractor, except single-family home and duplex properties where the owner may elect to sign as an owner-builder.
verified Aug 10, 2026 · source
Building inspections are self-scheduled online 24/7; requests received by 3 PM on a business day are scheduled for the next business day.
verified Aug 10, 2026 · source
Same-Day Building Permits: like-for-like replacements and simple upgrades for single-family homes and duplexes can be submitted and issued online without a set of building plans.
verified Aug 10, 2026 · source

Frequently asked questions

Does a duct repair need a permit?

Small like-for-like repairs are often treated as maintenance, but replacement and extension are permitted mechanical work — and once the altered footage in unconditioned space passes roughly 40 linear feet, the Energy Code's sealing-and-testing requirements generally come with it. Describe the real scope; cities notice 'repairs' that replace half a system.

What leakage does the HERS test allow?

The allowed leakage is a percentage of system airflow set by the Energy Code, and it differs for new, entirely replaced, and altered duct systems. The practical version: mastic at every joint, tested by an independent HERS rater, results registered — an unregistered test doesn't close the permit.

What R-value do ducts need?

Title 24 sets duct insulation by climate zone — commonly R-6 or R-8 for ducts in unconditioned space, with R-8 required in many zones. The CF1R-ALT documents the value for the project's zone, and both the inspector and the HERS rater look at the duct label.

Do I need a separate permit if I'm also replacing the furnace or AC?

Usually one mechanical permit covers both scopes, but the energy paperwork compounds — the equipment changeout triggers its own measures and the duct replacement its own. The trap is pulling an equipment-only permit and 'discovering' the duct replacement at final.

Other jobs in Mountain View

AC changeout Battery storage EV charger install All Mountain View permits All California jobs

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