How To Calculate Rebuilding Costs For Home Insurance? 
I generally agree with David 's answer . But I would add a few more items to consider . What your agent is developing in a Replacement Cost Calculator is only an estimate . The actual replacement of home depends on a number of factors that might change by the time loss occurs . For example we can identify that building one hose back in the instance of a total fire loss will likely cost more than the original building costs were when the builder may have building an entire subdivision . Yet losses to insured homes can be substantially more than expected if an entire city shares the same loss . That is what you get in some tornado or hurricane events.The fact that so many are affected increases do to shortage of materials and labor . So , here is what I recommend : Get as close to a number that you and your agent think represents the total replacement cost . Then buy an Extension of coverage . Many companies sell this at increments of 25 % ,50 % or even 100 % . What the extension does is move the limit to a higher level of protection at the time of loss if needed . An example would be to take the estimated replacement cost of 300,000 up to 375,000 in the event more coverage is need on the home at time a of loss and a 25 % extension has been purchased . 