A builder’s number can be accurate for the work described and still leave a large gap in the total amount needed to finish the project. The problem is usually not one dramatic surprise. It is the accumulation of site work, connections, allowances, carrying costs and finish items that sit outside the base contract.
Start with the contract, not the sales number. For every item below, mark it as included, excluded, allowance or unknown. An unknown is a budget risk until the answer is written down.
Land and site costs
- Land purchase and closing costs. The lot, title work, recording fees and legal costs may be entirely separate.
- Demolition. Removing an old cabin, home, foundation, septic component or outbuilding may require permits and disposal fees.
- Tree and stump removal. Clearing prices can change with access, equipment needs and disposal.
- Excavation. Confirm whether the price is fixed, an allowance or based on assumed soil.
- Imported fill and soil correction. Unsuitable soil can require removal, engineered fill or compaction testing.
- Rock removal. Blasting or mechanical removal is often treated as an unforeseen condition.
- Rough and finish grading. The excavator may leave the site safe but not ready for lawn installation.
- Drainage and retaining work. Swales, drain tile, culverts and walls can become necessary after final elevations are known.
- Erosion and shoreland controls. Silt fencing, stabilization, mitigation planting and inspections may be owner costs.
Utilities and access
- Permanent electrical service. Include utility charges, trenching, meter equipment and any long service run.
- Temporary construction power. The temporary pole, panel and energy use may not be in the house price.
- Well or municipal water connection. Depth, pumps, trenching, tap fees and restoration all matter.
- Septic, holding tanks or sewer connection. Separate permitting, pumping access and soil conditions can affect the total.
- Gas or propane. Budget the tank, regulators, trenching, first fill and rental or purchase decision.
- Internet and communications. Rural extensions can require construction charges or alternate equipment.
- Driveway and culvert. A construction entrance is not necessarily a finished gravel, asphalt or concrete driveway.
Finishes and allowances
- Cabinet and countertop overruns. Layout, hardware and edge details can exceed a basic allowance.
- Flooring upgrades. Include material, underlayment, transitions and installation differences.
- Lighting and electrical upgrades. Decorative fixtures, extra receptacles, exterior circuits and service changes add up.
- Plumbing fixtures. Faucets, shower systems, sinks and installation accessories may exceed the scheduled amount.
- Appliances and ventilation. Confirm delivery, installation, range hood ducting and required electrical work.
After the builder leaves
- Landscaping. Topsoil, seed, sod, trees, mulch and restoration can be a substantial final phase.
- Decks, patios and exterior stairs. Plans may show them even when the contract excludes them.
- Construction-loan interest and carrying costs. Interest, inspections, taxes, insurance, storage and temporary housing continue during the build.
- Move-in equipment. Window coverings, furniture, water treatment, generator, dock or lawn equipment may be needed quickly.
How to use the list
Do not automatically add a worst-case number for every item. First identify which costs apply, obtain a realistic low and high estimate, then apply contingency to the additional costs that remain uncertain. Keep allowances separate from fixed-price items so you can see where decisions or site conditions could move the budget.
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