Adding buildings to an operating self-storage facility can look simple on an aerial photo. The open corner by the back fence seems ready for another row of units. A due diligence survey tells you whether that corner can really hold new buildings once property lines, easements, setbacks and drive lanes sit on the same map. In Phoenix, steady commercial growth keeps pushing storage owners to add units on land they already hold or to buy the lot next door. The survey turns that idea into facts a designer, lender and city reviewer can work from.
Confirm Where the Self-Storage Expansion Can Actually Fit
A due diligence survey shows the true buildable area by mapping the boundary against everything that limits where a building can go. Open ground and usable ground are rarely the same size. Setback lines, recorded easements and drainage areas often take a large bite out of what looks free.
Start with the boundary. Fences around storage facilities don’t always follow the property line. A fence set a few feet inside the line can hide usable land, while a fence set outside it may enclose land that belongs to someone else. The surveyor compares deeds, recorded plats and field evidence to show where the lines really fall.
Next, look at what sits on the land. Many commercial sites hold stormwater in on-site retention basins, and an owner usually can’t shrink a basin just to make room for more units. Utility easements may also run along the rear or side of the lot. When the survey places these features next to the setback lines, the designer can see the real footprint left for new buildings. Setback distances come from local zoning, so confirm them with the city or your design team.
Check Access Before Adding More Storage Buildings
Access often decides how many new buildings a storage site can handle. Customers arrive in cars, pickups and rental moving trucks. Each vehicle needs room to enter, turn and leave without backing into a building or a gate.
Look at the entrance first. A survey can show where the driveway meets the public street, where the gate sits on the lot and whether the entry crosses a neighbor’s land or a shared access easement. If your facility shares a driveway with an adjoining business, the recorded easement terms may limit how much new traffic you can send through it. A title review paired with the survey brings those terms to light.
Inside the fence, new buildings eat into drive aisles. Fire access lanes and truck turning paths often set the minimum aisle width, and the fire department or city reviewer usually has the final say. Accurate measurements of today’s aisles show the designer whether a new row fits without squeezing circulation too tight.
Map Existing Improvements That Could Restrict the Site Plan
Existing improvements can block an expansion even when the land looks open. A survey locates buildings, walls and utilities so nobody draws new units on top of something that has to stay. On an older facility, some of these items may not appear on any earlier plan.
A due diligence survey for a storage expansion commonly picks up features like these:
- Existing storage buildings and covered RV or boat parking canopies
- Perimeter walls, fences and security gates
- Light poles, cameras and overhead power lines
- Visible utility features such as manholes, valves, transformers and backflow devices
- Retention basins, drainage inlets and noticeable grade changes
- Paving edges and striped parking near the office
Underground lines need extra care. A surveyor maps what shows on the surface along with what records and Arizona 811 markings reveal, but buried lines don’t always match their paperwork. Ask whether your scope includes private utility locating before anyone relies on the drawing for new foundations.
Match Survey Scope to the Expansion Decision
The right survey scope depends on the decision in front of you. An owner who only wants to know whether a few units fit needs less data than an owner who plans to finance a large addition. Buying the adjoining parcel changes the scope again.
A boundary survey confirms the property lines and shows improvements near them. A topographic survey adds ground elevations, which matter for grading, drainage and building pads. An ALTA/NSPS Land Title Survey ties boundary and improvement data to the title commitment and often serves lenders and buyers in commercial deals. Some expansions call for a mix, such as an ALTA survey with selected optional items plus topography.
Tell the surveyor what you plan to build and who will use the drawing. Share the title commitment, any earlier surveys and a concept plan if one exists. With that context, the surveyor can recommend a scope that answers your real question instead of a generic package.
Resolve Survey Constraints Before Committing to Expansion
Survey findings cost the least to address before contracts, loans and building plans lock in. Once the drawing shows a conflict, you still have time to redesign, negotiate or step back. After closing or permitting, those choices shrink fast.
Some constraints have a paper fix. The holder of an old easement for an abandoned utility line may agree to release it. You and a neighbor may settle a small boundary gap with a written agreement. An attorney or title company usually handles that paperwork because it changes legal rights.
Other constraints shape the design instead. If a retention basin or shared drive can’t move, the team can size the expansion around it. With commercial growth keeping land in demand, a clear picture of your limits helps you decide whether to build on the current parcel, add the lot next door or wait.
Frequently Asked Questions
Should a due diligence survey be updated if the property was surveyed years ago?
Often it should. Storage sites change as owners add canopies, repave lots or install new utilities, and neighbors build too. Lenders and title companies may want a survey dated close to the transaction, so check their date requirements before relying on an old drawing.
Can a due diligence survey cover multiple parcels in one self-storage property?
Yes. Many storage facilities sit on two or more parcels that an owner bought at different times. The surveyor can map all of them on one drawing and show whether their shared lines meet cleanly without gaps or overlaps, so provide the legal description and title information for each one.
Should vacant land beside an existing storage facility be included in the survey?
Include it if building on that land is a real possibility. Surveying both properties together shows how they connect for entry, stormwater and utility service. Buying the lot first and surveying later can uncover problems, like a recorded easement across the middle, after you’ve already signed.
