Plenty of homeowners look out at a deep backyard and see a second building lot. Some want to sell it, some want to build for a family member, and some just want to free up value they aren’t using. The idea is simple, but the approval process is where many lot splits stall.
A subdivision survey is the survey that divides one parcel into two or more new lots. It shows the new lines, dimensions, corners, easements, and legal descriptions that local officials review before the split can be recorded. If you plan the survey around zoning, access, and utilities from the start, you’ll avoid redesigns and wasted fees.
Evaluate Whether the Backyard Can Form a Separate Lot
Start by checking local zoning rules. Most zoning codes set a minimum lot size, lot width, and street frontage for each district. Both the new lot and the lot with your house must meet those rules after the split, unless a variance is granted.
A boundary survey is a smart first step. Recorded lot sizes in old deeds and tax maps aren’t always accurate, and a few feet can decide whether a split works. The surveyor will locate your corners, measure the true area, and show existing buildings, fences, and encroachments.
Before paying for full design work, check these items:
- Minimum lot area, width, and depth for your zoning district
- Whether your existing house will still meet setbacks after the split
- Deed restrictions or HOA covenants that limit dividing lots
- Any recorded easements crossing the backyard
Call your local planning or zoning office with these questions early. Terms differ by place, so a backyard split might be called a lot split, minor subdivision, or simple land division. The name affects which forms, fees, and review steps apply.
Plan Lot Dimensions and Building Setbacks
Once you know the rules, the surveyor can help sketch where the new line should go. Setbacks are the minimum distances a building must stay from property lines. They shrink the area you can actually build on, so a lot that meets the size rule may still have a tiny building area.
The new line also changes things for your current house. A garage, shed, deck, or pool that sits fine today could end up too close to the new line. In some cases, a small shift in the line solves the problem. In others, a structure may need to move or come down.
Ask your surveyor to show the building envelope for the new lot. That’s the space left after front, side, and rear setbacks are applied. Buyers, builders, and lenders will want to see it, and it tells you right away whether the lot is worth creating.
Establish Street Access for the New Parcel
Access is the most common reason backyard lot splits fail. Many codes require each lot to touch a public street for a set distance. A lot tucked behind your house often has no frontage at all.
There are a few ways owners solve this, though not every option is allowed everywhere:
- A flag lot, where a narrow strip of land runs from the street back to the rear lot
- A recorded access easement across the front lot
- Frontage on a side street if you own a corner lot
- Access from a public alley, where local rules allow it
Each option brings its own rules. Flag lot strips may need a minimum width for driveways and fire trucks. Shared driveways should have a written maintenance agreement so future owners know who pays for repairs. A new curb cut may also need a separate driveway permit from the city, county, or road agency.
Account for Utilities, Drainage, and Site Constraints
A new lot needs its own water, sewer, electric, and often gas service. Your current house lines may already run through the backyard. If the new line splits the yard, your existing lines could end up crossing someone else’s lot, which usually calls for a recorded easement.
Sewer is a big question. The new lot needs a way to reach the public sewer, and gravity lines need enough slope to flow. If public sewer isn’t available, a septic system brings its own lot size and setback rules, which vary by health department.
Drainage matters too. Backyards often carry runoff from neighboring lots through swales or low areas. A topographic survey can show slopes, low spots, trees, and flood zone limits that affect where a house can sit. Find these constraints before the lot lines are final, not after.
Prepare the Subdivision Survey for Local Review
The final subdivision survey is the drawing local officials review and approve. It usually shows the new lot lines with bearings and distances, the area of each lot, set corner markers, easements, existing buildings, and street frontage. It also includes new legal descriptions for each parcel.
The surveyor sets physical corner markers, often iron pins, at the new corners. Review may involve planning, engineering, health, and utility departments. Once approved, the plat or survey is recorded with the county, and new tax parcels are created.
Timing varies by community and project scope. A simple split might move in a few weeks, while a split needing a variance or extra review can take months. If you plan to sell or build on a deadline, confirm the review schedule early and build in extra time.
Frequently Asked Questions
What is a subdivision survey?
A subdivision survey divides one parcel of land into two or more new lots. It shows new boundary lines, lot sizes, corners, easements, and legal descriptions. Local officials review it to confirm the lots meet zoning and subdivision rules. After approval, it’s recorded so the new lots can be sold or built on.
How much does a subdivision survey cost for a lot split?
Cost depends on lot size, terrain, records research, and how much local review is required. A simple two-lot split usually costs less than a larger subdivision. Extra work, like topographic mapping or easement drawings, adds to the price. Ask your surveyor for a written quote that lists what’s included.
How long does a backyard lot split take?
Fieldwork and drafting may take a few weeks depending on the surveyor’s schedule. Local review can add weeks or months, especially if a variance is needed. Recording and new tax parcel setup take a bit longer after approval. Start early if a sale, loan, or building permit depends on the split.
Can I split my lot if the backyard has no street frontage?
It depends on your local rules. Some places allow flag lots or recorded access easements, and others don’t. Corner lots and alley access may offer other options. Check with your planning office before paying for detailed survey work.
Will splitting my lot affect my mortgage?
It can, because your lender holds a lien on the whole property. Many lenders must approve a split or release the new lot from the mortgage before it’s sold. The process and paperwork vary by lender and title company. Contact your lender early so the split doesn’t hold up a sale.
Land Surveyors are professionals who make precise measurements to determine the size and boundaries of a piece of real estate. While this is a simplistic definition, boundary surveying is one of the most common types of surveying related to home and land owners. If you fall into the following categories, please click on the appropriate link for more information on that subject:
