If a custom home finishes materially over its contract price, the cause is almost always one of these two mechanisms rather than anything dramatic. Both are legitimate and unavoidable in custom work. Both are manageable if you understand how they operate.
Allowances
An allowance is a number in the contract standing in for a decision you have not made yet — tile, plumbing fixtures, lighting, appliances, millwork, flooring, hardware, countertops. The contract is priced with that number in it, and when you select the actual item the difference is added or credited.
Allowances run over for a structural reason: a builder pricing competitively has an incentive to set them low, because a lower total wins the job and the overrun arrives later. This is rarely dishonest. It is what the competitive dynamic produces unless a buyer specifically resists it.
- Insist on a category-by-category schedule. A lump-sum "finishing allowance" is not a schedule and cannot be tested.
- Establish whether each figure is supply-only or supplied-and-installed. This single distinction moves allowances substantially.
- Go to the suppliers during your conditional or preconstruction period and price your actual preferences against the allowance. Do this for tile, plumbing and lighting at minimum — they are the three that overrun most often.
- Confirm what happens if you come in under. Most contracts credit the difference; some do not, and that should be a conscious decision rather than a discovery.
- Confirm whether the builder’s fee or markup applies to allowance overruns.
| Category | Why it overruns | What to do |
|---|---|---|
| Tile and stone | Quoted per square foot at a builder-grade price; setting labour for large-format or patterned tile is far higher | Price your actual selection including setting labour, not material alone |
| Plumbing fixtures | Allowance often reflects mid-grade; the fixtures in the inspiration photos are not | Price the specific fixtures you want, including rough-in valves |
| Lighting | Fixture count on a custom plan is frequently higher than the allowance assumed | Get a lighting layout before the allowance is set |
| Millwork and cabinetry | Linear-foot allowances rarely reflect custom detailing, interior fittings or specialty finishes | Get a millwork quote against your actual drawings |
| Appliances | Allowance may exclude installation, ventilation and panel-ready cabinetry costs | Confirm what the figure includes beyond the appliance price |
| Landscaping | Frequently excluded entirely, then required by a community covenant deadline | Confirm inclusion, and check any covenant completion deadline |
Change orders
A change order documents any alteration to scope, price or schedule after the contract is signed. Every one should be in writing, priced before the work is performed, and signed by both parties. A verbal change is the most common source of a dispute at possession.
- Require the price BEFORE the work proceeds, not after. "We will figure it out" is how a small change becomes an argument.
- Require the schedule impact to be stated alongside the price. A change that costs little and delays four weeks is not a small change.
- Establish the builder’s markup on change orders in the original contract, so it is not negotiated when you have no leverage.
- Keep a running log of change orders with a cumulative total. Individually they feel minor; in aggregate they are the difference.
- Distinguish client-initiated changes from builder-initiated ones and from those caused by unforeseen conditions. Who pays should follow from which it is.
Finish your selections before construction starts. Buyers who complete selections in advance experience dramatically fewer change orders, less schedule slip and a smaller gap between the contract price and the final cost. It is unglamorous and it is the single most effective cost control available to you.
The contingency you should hold
Hold a contingency of your own, separate from anything in the builder’s number, and treat it as spent. Its purpose is not to fund upgrades — it is to absorb the unforeseen without forcing a decision you would not otherwise make. A buyer without a contingency ends up value-engineering the finishing package to pay for a foundation problem.