AC installation in Thousand Oaks
The right permit office for your address, the right tests for your ZIP, a system sized to the house.
One service area, three permit offices: that is the first thing to know about installing air conditioning around Thousand Oaks.
Inside the city, including Newbury Park and the Ventura-side Westlake neighbourhood, the City of Thousand Oaks Building Division at 2100 Thousand Oaks Blvd issues the permit. An air conditioner changeout needs a site plan showing where the equipment sits, the lot dimensions and the unit's distance from the property line, and plans have gone through the TO/24 portal since 1 September 2025.
Three offices, two climate zones
Thousand Oaks and Newbury Park
City Building Division, with the site plan for the outdoor unit.
City of Westlake Village
Around Westlake Lake on the LA County side, building and safety is contracted to LA County, through 27001 Agoura Road in Calabasas or EPIC-LA.
Oak Park
Unincorporated Ventura County: Ventura County Building and Safety.
Charge check or not
91360, 91361, 91362 and 91377 are climate zone 9, so a HERS rater verifies the refrigerant charge. Newbury Park 91320 is climate zone 6, where it does not apply.
Sizing and placement
Because the city wants the outdoor unit's distance to the property line on the site plan, we settle the location on the first visit, with the side-yard clearance measured. We size the system from a load calculation, not from the old unit. A yearly HVAC maintenance visit keeps the new system in warranty shape; if you are not sure the old one is finished, start with AC repair. Replacing the furnace at the same time? See furnace repair for what we check first.
Order of work
Address and ZIP
Which office, which tests.
Site plan and quote
Equipment location, clearances, price.
Install
Usually one to two days.
Tests and final
Duct test, charge check in CZ9 ZIPs, inspection.
Installation questions from Thousand Oaks
Does a Thousand Oaks AC replacement need a site plan?
Yes. The city asks for a site plan showing the equipment location, lot dimensions and the unit's distance from the property line.
Who issues the permit in Westlake Village?
In the City of Westlake Village, LA County Public Works under contract. The Ventura-side Westlake neighbourhood is in Thousand Oaks and uses the city's office.
Why does my Newbury Park install skip the charge test?
Newbury Park 91320 is climate zone 6, where California does not require refrigerant charge verification on a changeout. The rest of the city is climate zone 9, where it does.
Planning a new system? We will check the address and quote it in writing.
Right office, right tests, right size
Call us, or send the form and we will call you back, every day, 7 a.m. to 11 p.m.
Coverage includes work in Westlake Village.