How do you estimate the cost to build a house?
Start with the floor area used by the builder’s quote and comparable local construction rates. This worksheet separates main-house construction, a separately priced garage, excluded site work, design fees, permits, land and accommodation. It gives a scoped low-to-high budget rather than inventing a location-based price.
Which floor area belongs in the house quote?
Known-area mode accepts the main-house area directly. Footprint mode multiplies length × width × equal-area floor count. Use the same gross, conditioned or usable area basis as the quote. Do not include a separately priced garage again in that main-house area; unequal floors need their measured combined area.
What is the new-house construction cost formula?
Base main-house cost = quoted area × rate. Add separately priced garage cost and construction items excluded from that base. Design fee and entered construction tax each use that construction subtotal. Permit totals and construction contingency follow, while land, transaction costs and accommodation are added outside that contingency.
Construction range = main-house area × rate + separate garage area × rate + excluded construction extras; add design, tax, permits and contingency, then land and accommodation
What does a two-thousand-square-foot example show?
At illustrative entered rates of 150–200 per sq ft, a 2,000 sq ft main house has a 300,000–400,000 construction base. Adding a separate 50,000 land purchase gives 350,000–450,000 before other items. The rates demonstrate arithmetic and are not a current national or regional price claim.
How should shell and complete-build quotes be compared?
The scope selector records the quote label and applies no hidden multiplier. A shell and a complete-build quote can have different inclusions, so their rates are not automatically comparable. Identify finishes, services, foundations and site work in the contract before adding separate extras.
Why are garage and external works separate?
Garage or outbuilding area can use a different rate from the main house. Enter its area and lower rate together, with an optional higher rate. Site work, excluded foundation work, utility connections and external works are project totals. Leave any item blank when it is already included in the base quote.
Where do land, fees and accommodation affect the budget?
Land purchase and its transaction costs stay outside construction contingency. Accommodation requires months and monthly cost together. The result shows build-only and combined-project ranges, plus combined cost per main-house sq ft. That combined unit figure includes land and extras, so it should not be compared directly with a builder’s construction-only rate.
Which inputs and assumptions should you verify?
Use the units printed on each input and data for the same project or product. Enter paired values together and leave unavailable optional extras blank. Entered comparable local quotes and their area basis determine the budget. Shell/complete is a scope label, not a price multiplier. Land remains outside construction contingency.
| Input | Unit basis | When used |
|---|---|---|
| Quoted main-house floor area | ft² / m² | areaMode:known |
| Main-house footprint length | ft / m | areaMode:footprint |
| Main-house footprint width | ft / m | areaMode:footprint |
| Equal-area main-house floors | as labeled | areaMode:footprint |
| Lower main-house quote per selected area unit | as labeled | all modes |
| Upper main-house quote per selected area unit | as labeled | all modes |
| Separate garage / outbuilding area (optional) | ft² / m² | all modes |
| Lower garage quote per selected area unit (optional) | as labeled | all modes |
| Upper garage quote per selected area unit (optional) | as labeled | all modes |
| Excluded site / earthwork quote (optional) | as labeled | all modes |
| Excluded foundation quote (optional) | as labeled | all modes |
| Excluded utility connection quote (optional) | as labeled | all modes |
| Excluded external works quote (optional) | as labeled | all modes |
| Design fee on construction subtotal (%) (optional) | as labeled | all modes |
| Tax on construction subtotal (%) (optional) | as labeled | all modes |
| Total permit / survey quote (optional) | as labeled | all modes |
| Construction contingency (%) (optional) | as labeled | all modes |
| Land purchase cost (optional) | as labeled | all modes |
| Land transaction costs (optional) | as labeled | all modes |
| Construction accommodation months (optional) | as labeled | all modes |
| Monthly accommodation cost (optional) | as labeled | all modes |
How can you compare and save a calculation?
Calculate a baseline and save it to comparison, then change one known value for another scenario. Copy or share the itemized result, download the input and result sheet, or print the worksheet. Clear changes removes current inputs and results, and refreshing starts clean.
Which related calculators support the next step?
Use Home Addition Cost Calculator and Concrete Slab Cost Calculator. Verify the printed units and scope before using their result as an input to this worksheet.
