What a Construction Progress Retainer Delivers, Month by Month

A retainer is a schedule, not a discount. That is the first thing to understand about the construction line on our rate card. What you are buying is the same flight, flown the same way, on a fixed cadence, with a document at the end of each one that someone other than you can act on.

This article walks a ten-month build — a custom home outside Benson, or a small commercial shell in Sierra Vista — through the three retainers. Three people read a progress package: the general contractor, the lender's draw inspector, and the owner. They want different things from it.

The three tiers

A one-off visit is $550 for media only, or $950 with the orthomosaic and PDF. So the honest arithmetic: the monthly retainer is not cheaper per visit than a media-only one-off. It adds the PDF and the schedule. The saving appears at bi-weekly ($700 a visit, with orthomosaic) and weekly ($600 a visit, full set), because planning, driving and control setup are spread across the term.

Travel is waived at every tier, since Zone 2 and 3 charges are dropped on jobs over $600. Sierra Vista sits in Class D airspace, so flights there need an authorisation the rest of the county does not — our problem to arrange, but the reason we ask for a fixed visit day rather than a call the night before.

What each deliverable is for

The 25–30 stills are the record: obliques from the four corners at two altitudes, a nadir over the pad, and detail frames of whatever changed. Every frame carries a timestamp and a coordinate. For the owner in Tucson, this answers "what happened this month." For the GC, it is a dated defence when a question comes up in month nine about what was in place in month three.

The 60-second video is for people who will not open a PDF. It has almost no evidentiary value, and we would rather say so.

The orthomosaic is a flat, scaled, measurable map of the site. Flatwork, driveway extents, trench runs and swales can be measured on it directly, and stacked visit over visit it shows change in a way obliques cannot. If there is a cut or import pile on site, volumetrics are $200 per pile against the same flight.

The progress PDF is written for the lender. More on its contents below.

Why the lender cares

On a construction loan the money is released in draws against a schedule. Fannie Mae's single-close guidance puts it directly: funds are "drawn and disbursed in accordance with the construction contract and the draw schedule," undrawn funds are "held back by the lender," and "periodic inspections should be made to confirm that work is progressing as scheduled prior to issuing draws."

In practice a third-party inspector compares the percentage billed on each line of the draw to what is physically on site, photographs the work and the stored materials, and reports to the bank. If the two do not agree, the draw goes back for revision, and as Levelset notes, "draw revisions can cause payment delays for everyone down the chain on a project."

We do not replace the draw inspector. We are not retained by the lender and we do not certify percent complete. What a dated aerial package does is shorten the inspector's visit and strengthen the GC's position. Line item "trusses set, 60%": the month-four obliques show the stack on the ground and the set portion on the walls. The inspector still counts; the photo says where.

Ten months, visit by visit

A composite schedule for a single-storey custom home. Real builds slip; the cadence does not.

1. Month 1 — clearing and pad. The baseline, before the excavator: existing grade, existing drainage, the mesquite about to be gone. The visit most people skip and most regret skipping.
2. Month 2 — footings, stem walls, slab. Orthomosaic of the poured footprint against the baseline. Utility trenches are visible now and buried next month.
3. Months 3–4 — framing and trusses. The most useful months for the lender. Wall lines, truss set and sheathing are all legible from the air.
4. Month 5 — dry-in. Roof deck, underlayment, windows. The nadir over the roof is also the baseline for any future storm claim.
5. Months 6–8 — interior. Stucco, soffits, the site itself. Weak months for aerial work.
6. Month 9 — flatwork, drive, final grade. Driveway extents, apron, finished swales.
7. Month 10 — completion. The last flight on the same plan as the first, and the timelapse assembled from all of them.

The completion timelapse is included on a 12-month term and $750 otherwise. If you expect to run past ten months — with a well to drill and a power drop to wait on, many here do — a 12-month term is usually the cheaper way to end up with the same thing.

Why the flight plan never changes

Every visit is flown from a saved mission: the same waypoints, altitude, heading and gimbal angle at each camera position, and as near the same time of day as the schedule allows so shadows match. Three reasons. The timelapse: a sequence from a fixed position reads as time passing; a sequence from roughly similar positions reads as a slideshow. Change detection: two orthomosaics flown on the same plan over the same ground control can be differenced; two flown differently cannot. And argument: when the frames from visit three and visit seven are taken from the same coordinate at the same angle, nobody debates the perspective. The camera did not move. The site did.

The accuracy side is in our mapping accuracy article: each visit is tied to the same site control, and we deliver progress and rough quantities, not pay quantities.

Keeping the aircraft away from the crew

A framing day puts eight people on site who are not part of our operation. The rule is 14 CFR § 107.39: no small unmanned aircraft may be operated over a human being unless that person is directly participating in the operation, is under a covered structure or inside a stationary vehicle that would protect them from a falling aircraft, or the operation meets one of the Subpart D categories.

We do not rely on a Subpart D category. Camera positions are planned so the aircraft stays offset from the work area, the nadir over the roof is flown when nobody is on it, and on a busy site we ask the superintendent for a twenty-minute window before the shift or at lunch. The plan is designed around the rule, not adjusted on the day.

What a progress PDF should contain

A PDF that works for a lender draw is not a photo album. Ours contains, in order:

• Site identification: address, parcel number, visit number and date, time on site, weather, pilot and aircraft.
• A one-page summary of what changed since the previous visit, written against the draw schedule's line items where we have it — "slab poured," "trusses set on east wing."
• A key plan — the orthomosaic or a site sketch — with camera positions numbered.
• The stills, numbered to the key plan, each with timestamp, coordinate and a caption saying what is visible and what is not. "Interior not observed" is a legitimate caption.
• Stored materials on their own page, because that is the part of a draw most often disputed.
• The orthomosaic at scale, and a plain statement that this is dated aerial documentation, not a percent-complete certification.

Send us the draw schedule at the start of the term and the summary page is written in its language. The service page has the full deliverable list, and the earlier overview of construction monitoring covers the general case.

If you have a start date and a draw schedule, send both through the contact form and we will tell you which tier fits the build and which months you can skip.