Flying a Site You Do Not Own Yet: Aerial Capture for Due Diligence

You are under offer on a property. A gravel pit, an industrial yard, a quarter section headed for subdivision, a building with a roof somebody is worried about. The condition period has a date on it, the vendor's disclosure is thin, and there are questions a site visit and a set of old photographs are not answering. Aerial capture is a good tool for this, and it comes with a complication that does not exist on any other job: the site is not yours.

That one fact changes the permissions, the confidentiality position and the data terms. None of it is difficult, but all of it is easier to settle before the flight than during a negotiation.

Who can authorise the flight when you hold no title

Two separate questions, and they are often collapsed into one by accident.

The airspace question is federal and it does not care about land title. The operating rules, the pilot certification, the standoff from bystanders and any authorisation needed to enter controlled airspace all sit with Transport Canada and, for controlled airspace, with NAV CANADA. None of that changes because the client is a buyer rather than an owner. The airspace article covers how that side is handled.

The ground question is entirely about title and occupation, and this is where a prospective buyer has nothing. Taking off from the property, landing on it, driving onto it, or placing a ground control target in the dirt all require the permission of whoever controls that ground. The vendor usually does, but not always: there may be a tenant with exclusive possession, a surface lease held by an operator, a grazing disposition, or a right of way across the access. The article on whose permission a drone survey actually needs sets out those layers, and they do not get simpler because a sale is pending.

So there are two practical routes:

• With consent. Ask for written access permission as part of the condition period, through the agent or the lawyer running the deal. Vendors frequently agree, because a buyer doing diligence is a buyer who is still buying. Put the date, the crew, the duration and the purpose in the request.
• From a standoff. Launch from land you do have rights to, a road allowance the municipality has cleared, or an adjacent property whose owner has agreed, and capture from there. Height buys horizontal coverage, so a standoff capture will often answer the extent and condition questions perfectly well. What degrades is measurement accuracy at the far edge of the block, which is a real limitation if the deliverable has to support a quantity.

What a standoff route does not do is make the flight unremarkable. Overflying property you are negotiating to buy, without the vendor knowing, is a choice with consequences inside a deal even where the flight itself is lawful.

The site is probably occupied, and people will call

A working yard has staff. A tenanted building has tenants. A quarter section has a farmer who has been on it for thirty years and has not been told the land is for sale. A drone appearing over any of them without notice generates phone calls, and the calls land on the vendor, which means they land in the middle of your negotiation.

The handling is the same as on any occupied site: let the people on the ground know in advance that a flight is happening, on what date, and what it is for, with whatever discretion the deal requires. The adjacent-property and overlooking considerations are the same ones covered in the article on whether you need the neighbours' permission to fly your own site, and they apply with more force when you are not the owner and cannot speak for the property.

Confidentiality and data terms, settled first

Normally the client owns the site and owns the imagery of it, and the only questions are retention and publication. Here the imagery is detailed, dated evidence about an asset that belongs to the other side of a live transaction, and it may show things the vendor would rather not have recorded. Four terms are worth settling before the flight:

• Who owns the data. You are commissioning it, so ordinarily you should. Say so, because a vendor granting access may assume otherwise.
• Who may be shown it. A lender, an insurer, an environmental consultant, a board, a joint venture partner. Each of those is a disclosure, and if the access consent is silent, it is silent in a way somebody can later object to.
• What happens if the deal dies. Can you keep the imagery? Can you use it in a later negotiation on the same property? Is the vendor entitled to a copy, or to its deletion? This is the clause people wish they had written.
• Retention and security. How long the contractor holds it and who at the contractor can access it. The general framework is in the article on drone data ownership, retention and confidentiality, and a pre-closing flight is the case where it stops being boilerplate.

What aerial capture genuinely settles inside a condition period

Used for the right questions this is a fast, cheap and unusually complete source of evidence. It is good at anything visible from above on the day.

• Actual extent and layout versus the plan. What has been built, paved, fenced, bermed or cleared, as against what the listing and the drawings claim.
• Surface condition at scale. Roof condition across a whole building, hardstanding and pavement condition across a whole yard, slope and bench condition across a whole pit. Not a sample. All of it.
• What is sitting on the site. Material stockpiles, equipment, pipe, abandoned plant, scrap, drums, tyres. Both because some of it is value and some of it is a removal liability, and because you will want to know on possession day whether it is still there.
• Measurable inventory. If there is saleable material on the ground, aerial capture can quantify it, which turns a vendor's number into a checkable one. The reconciliation caveats are in the article on why the drone volume and the scale house disagree.
• Drainage and ponding. Where water actually goes, which is one of the more expensive things to find out after closing and one of the easier things to see from above.
• Surface encroachments and unrecorded use. Tracks crossing the property, a neighbour's bins or storage over the line, a fence that does not follow the title boundary, an access nobody has documented.
• Vegetation and visible reclamation liabilities. Scale of clearing or regrowth required, visible disturbance, well sites and access roads. What aerial data can and cannot support on the reclamation side specifically is covered in the article on drone surveys and Alberta reclamation certificates.

What it does not settle, and will be asked to

Be clear about this early, because somebody will try to use the deliverable for one of these.

• Anything below grade. Buried tanks, buried waste, fill of unknown origin, utilities. None of it is visible, and the absence of a surface indication is not evidence of absence.
• Contamination. A stain is a reason to investigate, not a finding. Environmental assessment is its own discipline with its own standards.
• Structural condition. Aerial imagery shows a crack. It does not tell you what the crack means, and a report that implies otherwise is doing the buyer a disservice. The general limits are set out in what a drone survey cannot tell you.
• The legal boundary. An orthomosaic can show you a fence and can show you that the fence does not match the line on a plan. It cannot establish where the line is. That is survey work with professional standing behind it, as discussed in who signs off drone survey data, and for an encroachment that affects price you want the real thing.
• Anything inside a structure. Internal inspection is a separate scope with separate access requirements, and access to a building interior before closing is harder to obtain than access to a yard.

The dated baseline is the part people undervalue

Most buyers commission a diligence flight to find problems. The more reliable payoff is often the record itself.

A georeferenced, dated capture of the whole property at or near closing gives you a reference point that does not exist otherwise. When a dispute arises three months later about whether the stockpile was that size at possession, whether the scrap pile was there, whether the roof damage predated the sale, or whether the vendor removed equipment that was supposed to stay, there is either a dated record or there is a conversation between two recollections. The same logic underpins the use of aerial capture in a claim or valuation context, covered in the article on aerial imagery for an insurance renewal or a property valuation.

If you can only get one flight approved, this is the argument for taking it as late in the process as the schedule allows.

Making it fit the condition period

Condition periods are short and the clock does not stop for weather. Work backwards.

• Processing is not instant. A capture is a day. A deliverable is not. The turnaround article covers what sets the processing time and what actually causes the delay.
• Weather is the real schedule risk. Wind grounds flights, and the thresholds are discussed in the article on wind limits on a drone survey. In smoke season visibility can close a week. Budget a second attempt rather than assuming the first date holds.
• Season changes what you can see. Snow cover hides surface condition and makes measurement unreliable, for the reasons in the article on surveying under snow. A winter condition period on a site where surface condition is the question is worth flagging to your advisers rather than quietly accepting.
• Access consent takes its own time. A vendor's written permission may route through a lawyer, and on a tenanted or leased property it may need more than one signature.

What to settle before the drone leaves the ground

• Written access consent from whoever actually controls the ground, obtained through the deal channel.
• Confirmation of whether a tenant, surface lessee or operator also has to agree.
• Notification to the people working on the site, with whatever discretion the transaction requires.
• Data ownership, in writing, in your favour.
• The list of parties you may disclose the imagery to, agreed rather than assumed.
• What happens to the data if the deal does not close.
• Which specific questions the capture is meant to answer, so the flight is planned for them rather than producing a general picture.
• Whether anything needs survey-grade measurement, because that changes the ground control requirement and therefore the access requirement.
• The date the deliverable has to be in hand, which is before the condition date and not on it.

A diligence flight is one of the few places where a single day of aerial capture changes a price or a decision outright. It just needs the access question answered honestly at the start, and the data terms written down while everybody is still friendly.