Disclaimer and limits of use
Please read this if you are about to rely on a number from this site for anything that could hurt someone or cost money to put right.
These are estimates for planning
The calculators produce quantities and cost estimates to help you plan, budget and order. They are not a design, not a specification, and not a substitute for professional judgement about your particular project.
Site conditions, local amendments, material variation, workmanship and the specific circumstances of a job all affect the real answer, and none of them are visible to a calculator.
Structural, electrical, gas and life-safety work
Anything that carries load, carries current, carries fuel or protects people in a fire needs a qualified professional and, in most jurisdictions, the approval of a building authority. That includes beams, headers, joists, footings and retaining walls; consumer units, circuits and bonding; gas appliances and flues; and fire separation, egress and alarm coverage.
Where the site publishes a calculator touching these areas, it states the standard it follows and the scope that standard covers. Outside that scope the figure does not apply, and the page says so. Please do not extrapolate past it.
Codes vary and codes change
Results are presented for the market you select, against the code named on the page. Local authorities amend national codes, and codes are revised on cycles. A figure that satisfies a model code may not satisfy the amendment in force where you are building.
The last-verified date on each calculator tells you when the citation was checked. It is not a guarantee that the clause is still current.
Cost figures
Prices are regional estimates from national baselines, presented as ranges because material pricing genuinely varies by supplier, quantity and date. They are not quotations, not offers, and not financial advice.
Any figure carrying interest rates, repayments or affordability is arithmetic on the numbers you supply. It is not a lending decision, not a recommendation, and not regulated financial advice. Speak to a qualified adviser before acting on one.
Measurements from the field tools
The sensor tools are limited by consumer hardware. A phone used as a level is only as flat as its own case. A measurement scaled from a photograph is only valid in the plane of the reference object. A camera overlay carries no depth information and is a layout preview, not a measurement.
Each tool states where it stops being trustworthy. For anything that must be certified, set out structurally, or defended to an inspector, use the calibrated instrument the job calls for.
Limitation of liability
The site is provided as it is, without warranty of any kind, and is used at your own risk. To the fullest extent the law allows, the operator is not liable for loss arising from use of, or reliance on, anything published here.
Nothing in this statement limits liability that cannot lawfully be limited. The governing law and jurisdiction should be stated here by the operator before launch.