Splitting every cost equally feels like the neutral choice. It is not neutral. It is a choice among three lawful bases, and at many associations it is a choice the governing documents already made differently, years ago, in a clause nobody has read against the budget since.
Equal isn't wrong. Unexamined equal is.
This is the derivation thread from Show the Math: How HOA Assessments Are Actually Calculated run in reverse: instead of building the split from the documents, you check the split you already have against them. Four steps, one afternoon, and you will know something most boards do not know about their own budget.
In this guide
Step one: pull the allocation language
Somewhere in your CC&Rs is the language that says how costs are shared: equally, prorated by size or another measure, or by fixed percentages, sometimes varying by category of expense or by member class. The language is dense (terms like proportionate share, base equal, benefited properties, and limited common expense each carry a specific answer to "who pays"; the decoder is the jargon section of Show the Math: How HOA Assessments Are Actually Calculated), but it is finite, and this step is nothing more than finding it and writing down, per category, what it says. If the density is what has kept this audit from happening at your association, that excuse recently expired: reading allocation language and stating plainly what it prescribes is exactly the kind of interpretation modern AI has become good at, with the clause kept alongside as the check.
Step two: list the basis the budget actually applies
Now the other column: for each expense category, what basis does the current budget actually use to reach per-unit numbers? At many associations the honest answer is "everything is split equally because it always has been." Write that down too. The audit is the comparison of these two columns, nothing more.
Step three: the two-question check
For each category where the columns differ, ask two questions in order:
Is the basis prescribed by the documents? Then practice must match. A mismatch is a true discrepancy, whatever its age. My own association's documents turned out to prescribe special assessments prorated; that is not a preference I get to hold an opinion about, it is the rule I inherited when I bought in.
Or is the basis delegated to the board? Some documents leave the basis for some categories to the board's judgment. Then any basis is legitimate, if it was actually decided: on an agenda, discussed, minuted. The failure mode here is not the choice; it is habit standing in for a decision nobody remembers making. It is the same silent-decision disease as the leftover reserve line in When Reserves Get the Leftovers.
Where the documents are silent
Neither prescribed nor delegated is the one branch that is not a do-it-yourself project. Documents genuinely silent on allocation are a question for association counsel, not for a spreadsheet afternoon.
Step four: quantify one line
Abstract discrepancies do not move boards. Dollars do. Take one large line and run both bases:
| $48,000 landscaping line, 120 units | Small unit pays | Large unit pays |
|---|---|---|
| Split equally | $400 | $400 |
| Prorated, as the documents prescribe | $290 | $610 |
If your documents prescribe prorated and your budget splits equally, the small units have been subsidizing the large ones. By accident. For years. Nobody chose it, which is exactly the problem: the one thing an allocation must be is chosen, either by the documents or by a board on the record.
What to do with what you find
Sort the discrepancy list into its two kinds and treat them differently:
- Prescription violations: fix prospectively, in the next budget, with the clause cited in the packet. If the historical amounts are material, that conversation belongs with counsel, not in a hallway.
- Undecided discretion: agenda it, decide it, minute it. The current basis may well survive the vote. Now it is a decision instead of a habit.
Everything here is prospective. This audit is not an invitation to restate history or relitigate old budgets; it is how the next budget becomes defensible. The board that has run it walks into the annual meeting able to say the strongest sentence available: our split is the one our documents prescribe, and here is the math.
In the interest of transparency: this is the gap my company works on. We offer a free, easy-to-use tool governed by your association's own documents. It ensures every budget line is properly coded, who is responsible and on what basis it is shared, as the documents direct, or as an explicit board decision where the documents leave that to the board. The math underneath is deterministic. The method above works with or without it.
Related: Show the Math: How HOA Assessments Are Actually Calculated · Is Your Share Calculated the Way Your CC&Rs Say? (the owner-sized version of this check).
