Do I need a structural engineer’s letter for solar?

Does a Florida solar permit require a structural engineer’s letter?

In most Florida jurisdictions yes, and in Miami-Dade and Broward you should assume so. The letter is a Florida-licensed engineer certifying that your specific roof structure can carry the array under the design wind loads for your address — not that the equipment is sound in general. That is why a manufacturer’s generic letter is not a substitute and is commonly rejected: it says nothing about your rafters.

Required in the HVHZ?
Assume yes
Florida Building Commission
What it certifies
Your roof structure, at your address
Who may sign
An engineer licensed in Florida
Generic manufacturer letters
Usually not accepted in place of it

Last verified August 16, 2026

What the letter is for

An array adds weight, but weight is rarely the problem. The problem is uplift: wind getting under a rigid surface fixed to your roof and trying to pull it off, transferring that force into a handful of attachment points and from there into the timber or concrete beneath. The engineer’s job is to confirm that the structure can take it, at the design wind speed for your particular location, with the attachment layout being proposed.

That is inherently address-specific. Two identical houses on the same street can need different answers if one has been re-roofed, altered or built to a different code edition.

What the engineer needs from your house

  • Roof framing: member size, spacing and span, and the material.
  • The covering and what is beneath it, because attachment differs between shingle, tile, metal and low-slope membrane.
  • The design wind speed and exposure category for the address, which varies across Florida and matters more near the coast.
  • The proposed array layout and attachment spacing — change the layout and the calculation changes.
  • Existing conditions. Prior alterations, previous repairs and any known damage all affect the answer.

This is often why an installer wants attic access during a site survey. A design produced from satellite imagery and a roof measurement has not established any of the above.

How this interacts with product approval

These are two separate requirements that people conflate. Product approval says a component may be used in the High-Velocity Hurricane Zone at all. The engineer’s letter says your structure can carry that component in this arrangement at this address. Satisfying one says nothing about the other, and a submittal usually needs both.

What to ask

  1. 1

    Is the engineering included in the price?

    It is a real cost and it is sometimes excluded, which turns up as a change order after you have signed.

  2. 2

    Is the letter site-specific and sealed?

    It should name your address and carry a Florida engineer’s seal. If it names a product line instead of your house, it is the wrong document.

  3. 3

    What happens if the engineer says the roof needs reinforcement?

    It is not a rare outcome. Ask now who pays for it and whether the quoted price survives that finding, rather than discovering the answer mid-project.

  4. 4

    Does the layout on my proposal match what was engineered?

    Layouts change during design. A letter engineered for a different arrangement does not cover the one being built.

Common questions

Can my installer’s in-house engineer sign it?

If they hold a current Florida licence, yes — many reputable installers keep engineering in house or on retainer. The licence and the seal are what matter, not whose payroll they are on.

Does a battery need one too?

Sometimes, depending on weight, mounting and where it is being placed. It is a different calculation from a roof array but the same principle: can this structure carry this thing in this place.

Is this why permitting takes longer in some places?

Partly. Jurisdictions differ in how closely they examine structural submittals and in what they ask for, which is one of the genuine differences between one Florida municipality and the next rather than a matter of luck.

My roof is new. Does that mean it will pass?

A newer roof built to a recent code edition is a good starting point and not a conclusion. The engineer is checking the framing and the attachment against the loads at your address, and the age of the covering is only one input.

Sources

What each source supports on this page, and when we last verified it. Every source we use, with its freshness policy, is listed in the source register.

  1. Florida Building Code — high-velocity hurricane zone and wind-borne debris provisions

    Florida Building Commission

    Wind-load and permitting requirements applying to rooftop solar installations in Florida, including the High-Velocity Hurricane Zone in Miami-Dade and Broward counties.

    Verified August 16, 2026

  2. HVHZ product approval — Miami-Dade Notice of Acceptance and Florida Product Approval

    Miami-Dade County and Florida Building Commission

    That rooftop PV components installed in the High-Velocity Hurricane Zone require product approval, that a Florida Product Approval carrying HVHZ certification is accepted statewide while a Miami-Dade Notice of Acceptance is a local approval, that the two use the same test standards so only one is needed, and that approval attaches to individual products rather than to a system as a whole.

    Verified August 18, 2026 · Corroborated from manufacturer approval listings and trade coverage rather than read from the county product-control database, which is not reachable from the authoring environment. The mechanism is stable; a specific product’s approval status must always be checked against the live listing and never inferred.

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