Interactive tools
Work your decision through, not just read about it
Six tools covering the decisions homeowners actually face. Each publishes its full rule set on the page, so you can check the reasoning rather than trust an output.
All of them run entirely in your browser. Nothing you enter is transmitted — there is no server to transmit it to. And none of them returns a price: this platform holds no pricing observations, so a cost estimator would be inventing a number. What they return is the reasoning, which is the part that is actually useful.
Assess what you have
- What does my result mean? — Your number, read against guidance and against the conditions it was measured in.
- Is my system working? — The safe checks, in order, and where they stop.
Decide what to do
- Should I retest? — Time since the last test, plus what has changed in the house — the two things that decide it.
- Selling or buying? — Your side, your timeline, your result — and what should be in the amendment.
- Should I test? — Five reasons to test, and which one applies to you.
- Should I mitigate? — Above the action level it is recommended. In the 2–4 band it is your call, and this shows what tips it.
- Should I negotiate? — Which ask is realistic given your side, your days, and what you have in writing.
- Do I need a second opinion? — Five situations where a second opinion pays for itself, and one where it does not.
- Repair or replace the fan? — Four different problems present the same way. This separates them.
Compare your options
- Compare two quotes — Review both bids on the eight lines that explain almost every price gap.
Plan the sequence
- Build a testing timeline — Work backwards from your deadline to the day conditions have to start.
Related
- Research Center — the datasets these tools reason from.
- Homeowner guides — the full reasoning behind each decision.
- Editorial policy — why none of these returns a price.
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