A Property Can Be Near a City — and Still Be Far From Development
For landowners, developers, and real estate investors, some of the most important information about a property isn’t visible when you stand on the land. It’s found on a planning map.
A parcel may sit directly next to existing development and appear to be in the natural path of growth. But whether that land can eventually be annexed, served by municipal infrastructure, rezoned, subdivided, or developed depends on much more than proximity.
Two boundaries that are particularly important — and frequently confused — are the Urban Growth Boundary (UGB) and the Sphere of Influence (SOI). In Santa Clara County, there is another important layer to understand as well: the Urban Service Area (USA).
Understanding the differences can provide a much clearer picture of a property’s long-term potential.
What Is an Urban Growth Boundary?
An Urban Growth Boundary, or UGB, is a long-term planning boundary intended to establish where urban development should — and should not — expand.
The simplest way to think about it is: “How far should urbanization ultimately extend?”
UGBs are used to manage urban expansion and help preserve agricultural land, open space, hillsides, natural resources, and other areas that communities intend to protect from urban development. A property inside a UGB may therefore have a very different long-term planning context than comparable acreage outside it.
But there is an important distinction: Being inside the Urban Growth Boundary does not mean a property is entitled for development.
Current zoning, General Plan designation, infrastructure, environmental constraints, annexation requirements, water and sewer availability, and other land-use policies still have to be evaluated.
What Is a Sphere of Influence?
A Sphere of Influence, or SOI, is an official boundary adopted by a county’s Local Agency Formation Commission (LAFCO) for cities and special districts. Under California’s local agency formation framework, the SOI represents the probable ultimate physical boundary and service area of that local agency.
In practical terms, it asks: “If this city or district grows as anticipated, what territory could ultimately fall within its boundaries or service area?”
This makes an SOI much more than a line on a planning map. It is a formal governmental planning tool that LAFCO considers when evaluating annexations, reorganizations, service boundaries, and other changes to local government organization.
Generally, if territory outside a city’s existing SOI is proposed for annexation, the sphere would first need to be amended or addressed as part of the LAFCO process.
Spheres of Influence are also periodically reviewed, often in conjunction with Municipal Service Reviews, allowing LAFCO to consider changing growth projections, infrastructure, service capacity, population, and other conditions.
Why Does an SOI Matter to a Landowner?
An SOI can be an important early indicator of a city’s long-term planning and service relationship with surrounding land. If acreage is already within a city’s SOI — or if an SOI expansion is being considered — that deserves attention. It may signal that the area is relevant to longer-term discussions surrounding municipal boundaries, services, or annexation.
But this is where investors need to be careful. SOI does not equal development entitlement.
Being within a Sphere of Influence does not automatically:
- Change the property’s zoning
- Increase allowable density
- Provide water or sewer
- Guarantee annexation
- Approve a subdivision
- Guarantee future development
Instead, it is one piece of a much larger land-use puzzle.
UGB vs. SOI: What’s the Difference?
The easiest distinction is to look at the question each boundary is intended to answer.
Urban Growth Boundary
The UGB is primarily a growth-management and land-use planning boundary. It helps establish the long-term outer limits of urban expansion.
Sphere of Influence
The SOI is primarily a governmental boundary and service-planning tool established through LAFCO.
While these boundaries can sometimes appear as progressively larger areas surrounding an existing city, they should not automatically be treated as perfectly nested rings. Their relationship varies by jurisdiction.
And in Santa Clara County, there is another boundary that can be especially important.
The Third Boundary: Urban Service Area
For Santa Clara County landowners, understanding the Urban Service Area (USA) is critical when evaluating potential annexation and municipal services.
The USA generally represents the area where a city is positioned to provide urban services and where annexation may potentially occur under the County’s local boundary framework.
This means a property could potentially be: Inside a city’s Sphere of Influence but outside its Urban Service Area.
That distinction can materially change the property’s annexation and development outlook. So instead of looking at one line on a map, landowners should understand the relationship between:
Current City Limits → Urban Service Area → Sphere of Influence → Urban Growth Boundary
The exact relationship among those boundaries should always be confirmed for the particular jurisdiction and parcel.
Market Insight: Growth Can Be Visible Before Development Begins
This is where municipal planning becomes real estate strategy. A property’s future development story doesn’t necessarily begin when construction starts. It can begin years — sometimes decades — earlier.
Changes involving a city’s:
- Sphere of Influence
- Urban Service Area
- Urban Growth Boundary
- General Plan
- Zoning
- Infrastructure plans
- Water and sewer capacity
- Transportation network
- Annexation policies
can provide early indications of where future growth is being considered.
For a long-term investor or landowner, watching these changes can provide valuable context before the broader market recognizes their significance. The critical distinction is between future potential and present entitlement.
The Value of Optionality
Land buyers aren’t always purchasing today’s use. Sometimes they’re purchasing tomorrow’s options. Consider agricultural acreage immediately outside an existing city.
Today, the property’s highest and best use may remain agricultural. Municipal water and sewer may not be available. Annexation may not be possible. Development could be years away.
But if that parcel sits within the city’s long-term planning framework and future infrastructure is moving in its direction, an investor may view that land very differently from acreage with little realistic pathway toward urbanization.
That doesn’t mean speculation should replace due diligence. It means the property’s future optionality becomes part of the valuation conversation.
Two Properties Across the Road Can Have Very Different Futures
This is one of the reasons land valuation can be considerably more complicated than simply comparing acreage. Imagine two 20-acre properties located across the road from one another.
They have similar terrain. Similar agricultural use. Similar access.
At first glance, they appear comparable. But one may be within a city’s Urban Service Area and Sphere of Influence, while the other sits outside a critical growth boundary.
One may have infrastructure approaching the property. The other may face significant restrictions on extending urban services. On an aerial photograph, they may look almost identical. From a long-term land strategy perspective, they may be entirely different assets.
Neural Marketing Insight: Buyers Pay Attention to the Future Story
When sophisticated investors evaluate land, they aren’t simply processing acreage, zoning, and price. They’re building a mental picture of what the property could become.
That future story becomes stronger when it is supported by tangible planning evidence: municipal growth patterns, infrastructure investment, service boundaries, General Plan policies, annexation potential, and development activity. This is why marketing land effectively requires more than advertising its current characteristics.
The strongest positioning explains both: What the property is today — and what realistic options may exist tomorrow.
Overcoming the Challenge: When Land Appears Constrained
Some of the most interesting land strategies begin with a constraint. A property may be outside city limits. Infrastructure may not yet reach it. The current zoning may not support the owner’s ultimate objective.
Instead of immediately concluding that the property has no development potential, the better approach is to understand the pathway.
What would have to happen for the property’s next use to become possible?
That might involve an SOI amendment, Urban Service Area change, annexation, General Plan amendment, rezoning, infrastructure extension, environmental review, or a combination of several processes. Sometimes pursuing that pathway makes sense. Sometimes the better strategy is to reposition and sell.
And sometimes the strongest decision is simply to hold the property and preserve its optionality while municipal planning evolves.
What Should Landowners Be Watching?
If you own property near a city boundary, don’t rely solely on its current zoning.
Evaluate:
- Current city limits
- Sphere of Influence
- Urban Service Area
- Urban Growth Boundary
- General Plan designation
- Zoning
- Water and sewer availability
- Infrastructure plans
- Annexation requirements
- Environmental constraints
- Agricultural preservation policies
- Nearby development applications
- Proposed municipal boundary changes
Together, these factors tell a much more complete story about the property.
Is Your Property Really in the Path of Growth?
Owning land near Morgan Hill, Gilroy, San Jose, Los Gatos, or another Santa Clara County community doesn’t automatically mean the city will eventually reach it. But today’s zoning doesn’t always tell you the full story either.
Understanding the relationship between the Urban Growth Boundary, Sphere of Influence, Urban Service Area, General Plan, zoning, infrastructure, and annexation process can help determine whether a property has realistic long-term optionality — or whether perceived development potential is unlikely to materialize.
For landowners, that distinction can influence whether the best strategy is to sell, hold, reposition, pursue entitlements, or prepare for future opportunities.
