Free home addition calculators

Eight practical tools to model a construction budget, plan permits and soft costs, test resale, plan financing and compare actual contractor bids.

Estimate total costs for a new room or house expansion.

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Compare bedroom, kitchen, bathroom and sunroom budgets.

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Understand building up, stairways and structural upgrades.

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Model construction costs and a conservative rental scenario.

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Estimate the portion of cost potentially recovered at resale.

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Plan illustrative monthly principal-and-interest payments.

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Spot exclusions and compare two proposals side by side.

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Plan design, engineering, permit and contingency allowances transparently.

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