Budget assumptions

An assumption is not the same as a rule

A budget contains two very different kinds of numbers. Some are set for the board: a state assessment-increase cap, a reserve-study inspection cycle, a lender's minimum reserve allocation. Those thresholds vary by state and by your governing documents, so check yours before budgeting against a number you read somewhere else. Everything else in the budget, how much landscaping will actually cost, whether last year's insurance premium repeats, how big a contingency line should be, is a board assumption. Nobody outside the association set it. That is exactly why it needs to be written down and defended, not copied forward on autopilot.

Confusing the two is the most common way a budget goes wrong. A board that treats its own guess about vendor pricing as if it were a legal floor stops questioning it. A board that treats a real statutory cap as if it were a flexible internal guideline risks a budget that is not just optimistic, but unlawful.

The default assumption is "last year, plus a little"

Most boards build next year's budget by starting from this year's budget and adjusting a few lines. That approach has a name, and a hidden cost.

"the budgeting process starts from a base of zero, with no reference being made to the prior period's budget or actual performance" versus "the budget is prepared by taking the current period's budget or actual performance as a base, with incremental amounts then being added for the new budget period."

Source: Comparing budgeting techniques (Incremental v ZBB), Association of Chartered Certified Accountants

That second approach, prior-year budgeting, is faster and easier to delegate, which is why nearly every board defaults to it. The tradeoff is that a line nobody re-justifies can carry an outdated assumption for years without anyone noticing. Zero-based budgeting forces the opposite: every line starts at zero and has to earn its place again, at the cost of far more work to prepare.

Test the assumption before you keep it

You do not need to zero-base the whole budget to catch a stale assumption. You need to ask, line by line, what you are assuming and whether it still holds. Before assuming a vendor's price repeats, check the contract itself for a renewal or escalation clause rather than the invoice total. Before assuming a utility line is right because it matches last year's budget, compare it to last year's actual usage instead, a budget that matched itself but missed a hot summer is not a success. Before sizing a contingency line, treat the amount as a deliberate board policy choice you can explain, not a percentage borrowed from another association's budget.

None of these has one correct number. The discipline is asking the question every year, not landing on a specific figure once and reusing it forever.

Some assumptions are policy choices in disguise

Reserve funding is where this shows up most. A board that funds reserves just enough to keep the balance from going negative is not automatically underbudgeting, and a board that funds toward full reserves is not automatically the responsible one. Both are legitimate assumptions about risk, made by policy, not handed down as a single correct target.

"Threshold Funding: Establishing a Reserve funding goal of keeping the Reserve balance above a specified dollar or Percent Funded amount." "Baseline Funding: Establishing a Reserve funding goal of keeping the Reserve cash balance above zero."

Source: National Reserve Study Standards glossary, Community Associations Institute

The failure is not choosing baseline over full funding. The failure is not knowing which one you chose, and finding out only when the reserve study or a special assessment forces the question. See reserve contributions for how that choice turns into a specific budget line.