Tree inspection before buying a home in Washington or Oregon

What a pre-purchase tree inspection covers

Ask for an assessment by an arborist holding the ISA Tree Risk Assessment Qualification. ISA describes TRAQ as a voluntary qualification whose holders have been trained and tested in limited-visual and basic tree risk assessment and in the principles of advanced diagnostic techniques, with retraining and retesting every seven years [1]. Those are the three levels you will see quoted: a limited visual assessment is a walk-past from one side; a basic assessment is a 360-degree ground inspection with a mallet and probe and is the right level for a purchase; an advanced assessment adds drilling, sonic tomography or an aerial climb on a tree the basic level flagged.

The report should list every tree that could reach the house or the driveway, with species, trunk diameter, condition, the defects found (dead wood, cracks, cavities, conks at the base, lean, root damage from past construction, the list the ISA uses for homeowners [2]), and a rating of how likely failure is, how likely it would hit something, and what that would cost. Two regional checks belong in it. In a Douglas fir stand, laminated root rot: WSU says infected trees are hazardous and can be windthrown before any crown symptom shows, and the fungus survives in old stumps, so a cleared lot with fir stumps is a clue [3]. In western redcedar, the dieback pattern of thinning crowns, topkill and flagging that the state agencies ask to be reported [4]. In Oregon’s five quarantine counties, treat any ash tree as a future removal: emerald ash borer is there, and ash wood cannot leave the county without an ODA compliance agreement [5].

A risk report is a consulting product, priced per visit, and it is the one tree expense that comes before the offer rather than after. See tree risk assessment for what the rating scale means and arborist services for how to find and check one.

The trees are part of what you are paying for, too. The USDA Forest Service’s urban tree risk guide cites appraisal-industry estimates that as much as 10 to 30 percent of residential property value can be attributed to the landscape, trees included [29]. A sound, well-placed fir or oak is an asset; a hazard-rated one over the roof is a near-term bill. The report is how you tell which you are buying.

Pulling the property’s tree permit history

Tree permits leave a trail, and the trail tells you two things: what the seller removed, and what conditions now sit on the lot.

Portland. Urban Forestry’s permit status instructions send you to the PortlandMaps Permit/Case Search: enter the address, IVR number or application number, open the permit, and read the status line; updates can lag a day or more [6]. Portland’s no-development permits carry replacement conditions, tree for tree under 20 in DBH and up to inch for inch at 20 in and over, or a payment to the Tree Planting and Preservation Fund of $472 per DBH inch or $712 per on-site tree at the FY2025-26 rate [7]. A replanting condition on a permit the seller pulled is a planting you will own.

Seattle. SDCI’s research page recommends starting with its Permit & Site History Research Tool, which pulls records from several sources; the Seattle Services Portal holds permits from 2005 on by address or record number, the Shaping Seattle map shows active projects, and pre-2004 records are in the microfilm library [8]. Tree removal tied to construction is reviewed inside the building record, so search the construction permits too. SDCI’s GIS map shows whether the lot contains an environmentally critical area, which changes what can be removed [9].

Elsewhere the lookups are the city’s permit portal, but the conditions are the point. Kirkland puts a 12-month hold on new development permits after a healthy regulated tree is removed, 24 months for a landmark tree [10]; Keizer counts trees removed within 2 years before a land-use application as if they were still standing [11]; Lake Oswego requires one replacement tree per tree removed, two to one when a significant tree is removed for development [12]. Each city’s rule is in Washington tree removal permits and Oregon tree removal permits.

Heritage trees bind the buyer

A heritage designation runs with the land, and the seller may not mention it. In Portland, PCC 11.20.060(C) requires the owner or City Forester to record the designation on the deed and says a private owner’s consent “will bind all successors, heirs, and assigns”; it is unlawful to remove, prune or injure a Heritage Tree without written authorization from the City Administrator (11.20.060(H)), removal needs support from at least six members of the Urban Forestry Commission, and only a tree the Administrator finds dangerous can come out without that vote [13]. Pull the deed and the Heritage Tree list before you fall for the oak.

In Seattle, heritage trees are designated through SDOT’s Heritage Tree Program and sit in Tier 1 under the 2023 tree code, the most protected class, where removal is limited to hazard cases with replacement and must be done by a registered provider [9][14]. Lake Oswego designates heritage trees under LOC 55.06, and its Type I no-review permit is not available for them [12][15]. Vancouver’s heritage program takes trees of 36 in DBH or other criteria with owner consent that binds successors [16]; Albany’s Parks, Recreation and Tree Advisory Commission designates with owner consent and must consent to removal [17]; Tigard’s TMC 8.16 heritage trees are among the few trees on a single-family lot that need a permit there [18].

Utility easements and the pole-to-house wire

The title report’s easements tell you which trees the utility can cut and which you must. Under a transmission line the utility keeps the corridor clear: Clark Public Utilities caps tree height at 10 to 12 ft under its transmission lines, and Pacific Power keeps its transmission rights-of-way clear as a matter of policy [19][20]. The pole-to-house wire is the opposite problem. Puget Sound Energy does not trim service lines at all [21]; Seattle City Light prunes only the first 10 ft from the distribution connection and leaves the rest to the owner [22]; Avista calls the pole-to-house wire the homeowner’s responsibility [23]. A maple growing through the service drop is a trimming bill you inherit, and in Oregon anyone working within 10 ft of a line over 600 V must notify the utility first under ORS 757.805 [24]. Full detail by utility is on the utility tree trimming pages.

Who pays after closing

Once the deed records, the tree is yours, and so is the code that comes with it. In Portland the sidewalk and the parking strip are the abutting owner’s to repair (PCC 17.28.020), with 60 days after a Notice to Repair before the City does it and bills you, and the sewer lateral is yours from the curb face to the house (PCC 17.32.070) [25][26]; both are covered in tree root damage on your property. Insurance follows the same logic in both states. Washington’s Insurance Commissioner says policies usually cover wind and falling-tree damage to the house but not removal of a tree that fell without hitting a covered structure, with debris removal typically capped at an extra 5 percent of the dwelling limit [27]; Oregon’s Division of Financial Regulation says the same about a tree that damages nothing, and that a neighbor’s tree on your roof is a claim on your own policy [28]. The tree the arborist flagged in the report you read before closing is not a surprise the insurer will be sympathetic about afterward.

The insurance file to build before closing

Your state regulator’s guidance above is the rule to go by; national industry guidance fills in the details buyers ask about. The Insurance Information Institute’s homebuyer handbook (2023) suggests asking your insurance professional to pull the property’s C.L.U.E. loss-history report, the industry database of past claims on the address, so you can see whether a tree or wind claim was paid and whether the damage was fixed [30]. The same handbook says many standard policies cover trees, plants and shrubs at about $500 per item, and not for disease or poor maintenance, and that losses from failing to maintain the home are generally not covered [30]. ISA’s tree-values brochure gives the same order of magnitude: in most cases the allowable claim for any one tree or shrub is a maximum of $500 [31].

Two habits make a later claim easier. ISA recommends photographing your trees every year during the growing season, so you have a before picture if a storm or a vehicle damages one [31], and its mature-tree guidance is an inspection at least once a year [32]. Keep the pre-purchase arborist report with those photos; it is the dated record that a tree was sound, or that you acted on what it found.

Questions to ask the seller

Take the answers, the permit search and the arborist’s report into the inspection contingency together. A hazard-rated fir within a tree-height of the roof is a repair request like any other; the modeled cost of removing it is on tree removal cost, and whether the tree is too close to begin with is the question answered on is that tree too close to your house.