Which Professional Services
Does Your Site Conditions Require?
Government rules set the minimum requirements for your lot. If you’re in a community with a homeowners association, their rules often require even more. Your builder decides what to add beyond those two. Find your site conditions in the cards below, then get a SiteFacts report to confirm what applies to your specific property.
Find Your Site Condition. See What It Requires.
These are the most common triggers across PNW jurisdictions. Regulatory requirements vary by county. A SiteFacts report reads your specific parcel against local code before your builder draws a budget.
Many counties in the Pacific Northwest have rules that automatically kick in when your land slopes more than 15 percent. When that happens, the county will not issue a building permit until you provide an engineer’s report. Your builder cannot skip this step.
When soil is moved to level a site, the disturbed ground needs to be tested before a foundation goes on top of it. Clay soils are especially risky — they can look solid on the surface and still sink several inches after construction, cracking foundations and walls. An engineer tests how the soil will behave under load and how tightly it was packed down. That cannot be confirmed just by looking at it.
If your property is in a high wildfire hazard area and has a long driveway, the county may require that fire trucks can physically reach your home. That means your driveway width, turning radius, and overhead clearance all get reviewed. Your home’s structure may also need to meet fire-hardening standards. These requirements are getting stricter across Oregon, Washington, and Idaho.
Some properties are officially mapped by the county as being in a landslide-prone area. This is a legal flag attached to the land itself — it does not go away because the ground looks stable. Counties typically require an engineer’s assessment before they will issue a building permit on a property with this designation. SiteFacts flags this in your report.
If your property is near an area prone to erosion, the county may require a plan showing how water and soil movement will be managed during and after construction. Many counties now require this plan before they will approve a permit. Soil that swells and shrinks with moisture — common throughout the Pacific Northwest — causes more structural damage to homes each year than earthquakes and floods combined.
If your property is in a community with a homeowners association, the HOA may have its own design rules written into your deed. These can require you to hire a licensed architect, get a landscape plan approved, and submit drainage and grading plans to a review board — even on a flat, simple lot where the county requires nothing. You are legally bound by these rules the moment you close on the property.
Every Professional Service on an OYL Build
What each service reveals, when regulation mandates it, and what it typically costs. These cost ranges apply to PNW markets and will vary by jurisdiction and site complexity.
| Service | What It Reveals | Mandated When | Typical Cost |
|---|---|---|---|
| Boundary Survey | Property lines, encroachments, easements | Often required for building permit issuance | $500 to $2,500 |
| Topographic Survey | Slope %, drainage patterns, contours, buildable area | Required when a grading plan is required | $1,800 to $6,500 |
| Geotechnical Report | Soil bearing, settlement risk, expansive clay, water table | Slopes, fill sites, poor soils, earthquake-risk areas | $1,400 to $5,000 |
| Civil Engineering | Grading plan, drainage design, stormwater management, driveways | Significant site grading; septic system design; varies by county | Project-based |
| Structural Engineering | Foundation design, snow and wind loads, retaining walls | Complex or custom home designs; high snow load areas; earthquake zones | $8,000 to $30,000 |
| Compaction Testing | Whether fill soil was packed tightly enough to safely support a foundation | Any site where fill was placed; county building official may also require it | $200 to $500 per test |
| Landscape Architect | Slope stabilization, erosion control, drainage integration | Landslide/LM overlays, wildfire defensible space, sensitive areas | Project-based |
| Architect (ARC) | Building placement rules, HOA design requirements, energy standards | HOA and community design rules; custom or complex home designs | 8 to 15% of build cost |
Cost ranges reflect PNW markets. Jurisdiction fees are paid directly to the municipality and are separate from the above.
SiteFacts Reads the Regulatory Layer Before Your Builder Draws a Budget
Geohazard overlays, slope thresholds, landslide hazard designations, erodible soil classifications, seismic category, wildfire hazard designation, FEMA floodplain, NWI wetlands, and HOA and ARC presence when that information is available in county records.
When a builder knows before design starts that a parcel carries a geologic hazard overlay and will require a topographic survey and civil engineering, the budget includes those costs from the beginning. The graded risk decision becomes an informed one, not a surprise correction at permit submittal.
Building codes save approximately $11 for every $1 invested beyond older code generations, per National Institute of Building Sciences research. Professional services required by those codes are not expenses to be minimized. They are the mechanism by which the code’s protective value reaches the building.
Know Which Services Your Site Requires Before Your Builder Makes the Budget Decision
A SiteFacts report reads the regulatory layer specific to your parcel: the overlays, the slope classifications, the hazard designations, and the HOA presence. You get that intelligence before the budget is set, not after the permit is rejected.
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