# Mini Split Installation in Oak Grove, OR

> Mini split installation in Oak Grove for baseboard-heated houses and duplexes, with Clackamas County permits for this unincorporated area and the incentive.

URL: https://firlandsportlandminisplits.com/service-areas/oak-grove/

Service area, Oregon

Mini split installation in Oak Grove for baseboard-heated houses and duplexes, with Clackamas County permits for this unincorporated area and the incentive.

(971) 458-4515

Last Updated: November 12, 2026

49.1%

of Oak Grove homes heat with electricity (U.S. Census Bureau, ACS 5-year)

11.7%

of Oak Grove homes were built before 1940 (U.S. Census Bureau, ACS 5-year)

Permits

Clackamas County

Electric utility

PGE

## Rooms that need help in Oak Grove

### Baseboards and a Milwaukie address

About half of Oak Grove heats with electricity, and most of it mails as Milwaukie. The permits still come from the county.

### A duplex or a rental next door

Two units on two meters usually get two systems. The incentive for each is the higher one.

### An older house near the river

Oak Grove has as many pre-1940 houses as Milwaukie, many along River Road with basements and upstairs rooms.

## Half the houses heat with electricity

Most Oak Grove calls start with two things: a baseboard heating bill and a Milwaukie mailing address. About half the homes here heat with electricity, in houses from the 1950s to the 1970s and an older stretch near the river.

Baseboards are where a heat pump changes the bill most. [Firlands Portland Mini Splits](https://firlandsportlandminisplits.com/) starts with the living space, sizes each head to its room, and handles the Clackamas County permits that Oak Grove’s unincorporated status brings.

### The mix of houses

- 1950s to 1970s ranches and split-levels on baseboards
- duplexes and small plexes, many with an owner on one side
- older homes along River Road and near the Trolley Trail, some with basements and upstairs rooms

Project

## Inside an Oak Grove duplex, one system per side

### The problem

Each side heats with baseboards, and the owner, who lives in one side and rents the other, pays for the bills on her side and hears about them on the other. Neither side has cooling.

### The house

Each unit has its own meter and panel in the utility closet, an open living and dining room at the back, and two small bedrooms at the front. A shared attic runs over both, with a fire separation at the party wall. The address has a Milwaukie mailing address but sits in unincorporated Clackamas County, so the county issues both permits.

### What we decide, and why

One shared multi-zone outdoor unit ties both households to one compressor and one meter, so each side gets its own system. A 12,000 BTU head goes high on the back wall of each living room, throwing air toward the bedroom hall. The bedrooms keep their baseboards. Each outdoor unit sits on its own pad behind its own unit, at opposite ends of the back wall, so neither one sits under a bedroom window.

### The work

Two three-inch holes, one per side, each line set straight through the wall behind its head with a short cover to the pad. Each side gets a 20-amp, 240-volt circuit from its own panel, run through its own half of the attic without crossing the fire separation, and a disconnect beside its outdoor unit. The living-room baseboard circuits come off. Each line set holds a nitrogen pressure test and a vacuum below 500 microns, and both drains fall to the yard by gravity.

We schedule the rented side's day with the person living there a week ahead, contain dust around the wall opening, and finish that side in one day so their living room is back in use by evening.

### What it changes

Each household controls its own heat and cooling on its own bill, the living-room baseboards come off on both sides, and because both systems replace electric resistance heat in a duplex's main living space, each side can qualify for Energy Trust's $1,800 incentive.

Location

Oak Grove, near Oak Grove Boulevard and the Trolley Trail (unincorporated Clackamas County)

House

1966 side-by-side duplex, two 2-bedroom units of about 900 square feet, electric baseboards

Equipment

Two separate single-zone systems: one 12,000 BTU cold-climate head and outdoor unit per side

Price

$13,600 for both sides, permits included

Time on site

2 days, then the county's final inspections

## A Milwaukie address, a county permit

Oak Grove isn’t a city. It’s unincorporated Clackamas County, so the county issues every building permit here, mechanical and electrical.

Most Oak Grove addresses mail as Milwaukie, and the City of Milwaukie warns that a Milwaukie mailing address doesn’t put a home inside its limits. We check your parcel on the county’s map before applying.

| What we apply for | Who issues and inspects it |
| --- | --- |
| Mechanical permit: heat pump, heads, line sets | Clackamas County Building Codes |
| Electrical permit: new 240-volt circuit and disconnect | Clackamas County Building Codes |

The fees are in our price. [Mini split permits](https://firlandsportlandminisplits.com/guide/mini-split-permit-portland/) explains what each permit covers.

## Duplexes and the people living in them

Oak Grove has its share of duplexes, and where the owner lives on one side and rents the other, both sides need planning.

### Two systems or one

With two meters and two panels, we put a separate system on each side. A shared multi-zone unit is cheaper by a little and costs more later, because both households lose heat when it needs service.

### Scheduling around the rented side

We give the person living there a week’s notice, contain the dust around each wall opening, and finish their side in a day. [Mini split for rental property](https://firlandsportlandminisplits.com/guide/mini-split-for-rental-property/) covers access and notice in more detail.

## The incentive, side by side

Oak Grove is PGE territory, so Energy Trust of Oregon’s ductless incentive applies when a ductless system replaces electric resistance heat in the main living space.

| Your home | Energy Trust’s ductless incentive |
| --- | --- |
| Owner-occupied single-family house | $800 |
| Owner-occupied duplex, triplex or fourplex | $1,800 per qualifying home |
| Any rental | $1,800 |

The heads need an HSPF2 of 8.10 or better, the contractor signs the application, and it goes in within 60 days of the install. Gas-heated homes don’t qualify for this offer. [Mini split rebates in Oregon](https://firlandsportlandminisplits.com/guide/mini-split-rebates-oregon/) lists the conditions.

## Older houses near the river

Along River Road and the streets toward the Willamette, Oak Grove has houses from the 1910s to the 1930s, about as many pre-1940 homes, as a share, as Milwaukie.

Those houses often have a basement, plaster walls and rooms under the roof with no ducts.

### How the work changes

A head in an upstairs room usually runs its line set down the back wall; a basement head often needs a small condensate pump. Before 1978, paint and plaster may contain lead, so we set up dust containment before coring a wall. [Basement mini split installation](https://firlandsportlandminisplits.com/basement-mini-split-installation/) covers the lower floor.

## Where the outdoor unit goes on an Oak Grove lot

Most Oak Grove lots have room behind the house, so the outdoor unit usually goes on a pad at the back, out of sight from the street.

### What we look for

- a spot within the line-set limits of every head it serves
- at least a foot from the wall, and clear of a gutter outlet or roof valley that drops water on it
- away from a bedroom window, yours or the neighbor’s
- a stand above the ground where the yard holds water in winter

On a narrow lot or a duplex with a shared back yard, a wall bracket keeps the unit off the lawn and out of the way. [Mini split placement](https://firlandsportlandminisplits.com/guide/mini-split-placement/) shows the options.

## An old mini split that’s quitting

Some Oak Grove houses already have a mini split from 10 or 15 years ago. When it starts failing, the first question is whether the line set can stay.

We pressure-test the old line set with nitrogen and pull a vacuum. If it holds and the new unit’s refrigerant and pipe sizes match, a like-for-like swap is the simpler job; Firlands’ typical range for that is $4,000 to $8,000. If it fails, the lines are replaced too. [Mini split replacement](https://firlandsportlandminisplits.com/mini-split-replacement/) covers the choice.

## Which rooms get heads first

In a baseboard house we start where the heat costs most and work outward from there.

1. **The living space.** It runs its baseboards longest, and replacing them there is what qualifies the incentive.
2. **The bedroom used most.** Often the hottest room in July as well.
3. **Small rooms later.** They keep their baseboards; an outdoor unit sized with spare capacity can take another head without being replaced.

[Baseboard to mini split](https://firlandsportlandminisplits.com/baseboard-heat-to-mini-split/) covers the conversion step by step.

## Winter and summer on the river

Clackamas County’s heating design temperature is 24°F, and its summer design high is 88°F. The 2021 heat dome blew past both, with Portland’s airport at 116°F.

We size each head for both ends: enough heat at the design low, checked below it on a cold-climate unit, and enough cooling for a west-facing room on an 88°F afternoon.

### Not sized for the record

An oversized head handles the heat wave and then short-cycles the rest of the year, so we don’t size for the record. [Do mini splits work in cold weather?](https://firlandsportlandminisplits.com/guide/do-mini-splits-work-in-cold-weather/) explains the winter side.

## What goes into an Oak Grove price

Firlands’ typical range runs $4,000 to $8,500 for one head, $6,500 to $12,000 for two on one outdoor unit, and $9,000 to $18,000 and up for three or four.

A duplex with two separate single-zone systems is priced as two single-zone jobs on one estimate. Taking baseboard circuits off often frees enough breaker space to avoid a panel upgrade. [Mini split installation cost in Portland](https://firlandsportlandminisplits.com/guide/mini-split-installation-cost-portland/) has the full list of drivers.

## Services in Oak Grove

- [Service**Baseboard to mini split** Replace baseboard heat with a mini split: ductless heads take over in the rooms that use the most heat, and add cooling.](https://firlandsportlandminisplits.com/baseboard-heat-to-mini-split/)
- [Service**Single-zone installation** Single zone mini split installation: one indoor head and one outdoor unit for the room the furnace never reaches, sized to that room.](https://firlandsportlandminisplits.com/single-zone-mini-split-installation/)
- [Service**Multi-zone installation** Multi zone mini split installation: two to five rooms on one outdoor unit, each head sized to its own room and set to its own temperature.](https://firlandsportlandminisplits.com/multi-zone-mini-split-installation/)
- [Service**Basement** A basement mini split install for a family room, office or basement unit: heat, cooling, drier air and a drain that works below grade.](https://firlandsportlandminisplits.com/basement-mini-split-installation/)
- [Service**Replacement** Mini split replacement for an aging or failed system, reusing the line set and circuit only when they pass the test.](https://firlandsportlandminisplits.com/mini-split-replacement/)

## How a job usually runs in Oak Grove

### The call

You tell us the rooms and send a few photos; we give a rough range.

### The visit

We measure each room, look at the walls, the panel and where the outdoor unit can go.

### The estimate

A written estimate: each head, the line-set route, drains, circuit, permits and price.

### Install and handover

Pressure test, vacuum, startup, a walk-through, and the permits closed out.

## Neighborhoods, landmarks and routes

- River Road
- Oak Grove Boulevard
- Concord
- Rivervilla
- Courtney Avenue
- Jennings Lodge edge

### Landmarks

- Willamette River
- Trolley Trail
- Concord community center and library
- Elk Rock Island across the river
- Kellogg Creek

### Getting around

- McLoughlin Boulevard (99E) north-south
- SE River Road along the Willamette
- SE Oak Grove Boulevard east-west
- The Trolley Trail between Milwaukie and Gladstone
- MAX Orange Line at SE Park Avenue

[Open Oak Grove, Oregon in Google Maps](https://www.google.com/maps/search/?api=1&query=Oak%20Grove%2C%20Oregon)

## Oak Grove: questions

### What will a mini split cost me in Oak Grove?

Firlands' typical range is $4,000 to $8,500 for one head on its own outdoor unit and $6,500 to $12,000 for two heads on one. A duplex with a system per side is two single-zone jobs. Clackamas County's permit fees are part of the price; the written estimate sets yours.

### Does Milwaukie or Clackamas County issue my Oak Grove permit?

Clackamas County. Oak Grove is unincorporated, so the county issues the mechanical and electrical permits even though most addresses here mail as Milwaukie. The City of Milwaukie only covers homes inside its city limits.

### Should each side of an Oak Grove duplex get its own mini split?

Usually. With two meters and two panels, separate systems keep each household's power on its own bill and let one side be serviced without shutting off the other. Each side that replaces electric heat in its main living space can qualify for Energy Trust's $1,800 incentive.

### Is Oak Grove on PGE?

Yes. Oak Grove is PGE territory, so Energy Trust of Oregon's incentives apply: $800 for a single-family home and $1,800 for duplexes and rentals, when a ductless system replaces electric resistance heat in the main living space.

### Can a mini split work in an older Oak Grove house near the river?

Yes. Older houses along River Road often have basements and upstairs rooms with no ducts, which suits heads well. In a house built before 1978 we contain the dust when we cut plaster or old paint.

## Nearby service areas

- [Oregon**Oatfield** Mini split installation in Oatfield for 1960s and 1970s split-levels on the ridge: cooling the bedroom level beside a gas furnace, and county permits.](https://firlandsportlandminisplits.com/service-areas/oatfield/)
- [Oregon**Milwaukie** Mini split installation in Milwaukie for 1950s and 1960s ranches: replacing floor and wall furnaces, Milwaukie city permits, and the Home Energy Score at sale.](https://firlandsportlandminisplits.com/service-areas/milwaukie/)
- [Oregon**Gladstone** Mini split installation in Gladstone for electrically heated ranches, from ceiling cable heat to baseboards, with a city sign-off and Clackamas County permits.](https://firlandsportlandminisplits.com/service-areas/gladstone/)

## Guides for houses in Oak Grove

- [Decision Guide**Is a mini split a good choice for a rental property?** What Oregon law asks of rental cooling, what Energy Trust pays, and how to lay out heads in a house or a fourplex.](https://firlandsportlandminisplits.com/guide/mini-split-for-rental-property/)
- [Learn**What mini split rebates are available in Oregon?** What Energy Trust pays, which homes qualify, how state and city programs work, and what's changed for the federal credit.](https://firlandsportlandminisplits.com/guide/mini-split-rebates-oregon/)
- [Learn**Do you need a permit for a mini split in Portland?** Which permits a new or replacement mini split needs, what they cost, and which office issues them outside Portland.](https://firlandsportlandminisplits.com/guide/mini-split-permit-portland/)
- [Cost Guide**How much does mini split installation cost in Portland?** Typical ranges by job, what moves the number, and the public costs inside it.](https://firlandsportlandminisplits.com/guide/mini-split-installation-cost-portland/)

## Get an estimate in Oak Grove

Tell us which rooms aren't working and where the house is in Oak Grove.

(971) 458-4515