Use Rent vs Own in your AI

Install one skill in Claude, ChatGPT or Grok, then ask your question in plain words. Your AI looks up what you did not say, lists every assumption with its source, and replies with one link that opens Rent vs Own on your scenario. The tool works out the answer, so the figures you see are the tool's, not the chatbot's.

 Download brotools-rentvsownhouse.zip Open the tool

A .zip skill: SKILL.md (how to answer), references/ (every input, its range and the Quick Starts) and scripts/build_link.py (builds and checks the link). Read SKILL.md

Install the skill

Pick your assistant. The demo plays the steps; press a step to jump to it.

    Menus move as these apps update; look for Skills in Settings. Skills need the app's code tool switched on (Claude: Code execution and file creation). No skill support on your plan? Attach brotools-rentvsownhouse.zip or SKILL.md to the chat and say "use this skill".

    How to use it

    Ask as you would ask a friend. With the skill on, the AI keeps your figures, researches the rest, and hands you the link. It does not give the answer itself: the tool does, once you open the link.

    Should I buy an $800,000 house or keep renting for $700 per week?

    Using skill brotools-rentvsownhouse Searched: Western Australia transfer duty on $800,000 Searched: Average variable mortgage rate in Australia, November 2026 Ran scripts/build_link.py: link checked

    Your inputs

    • Property price: $800,000
    • Rent amount: $700 a week

    Assumptions

    1. Place: you did not say where. A rent quoted per week in dollars is how Australia quotes it, and $800,000 buys a 2-bedroom house in Perth, so the link starts from the Perth 2-bedroom house Quick Start (qs=perth/house-2br). Tell me your city and I will send a new link.
    2. Loan: a 20% deposit and a mortgage at 6.4% a year over 30 years, near the going variable rate for an owner-occupier in November 2026.
    3. Setup cost: 4.4% of the price, for Western Australian transfer duty on $800,000 (about $32,300) plus conveyancing and inspections.
    4. Ongoing costs of owning: $7,500 a year for council and water rates, insurance and upkeep.
    5. Growth and returns, from the Quick Start: house prices 4.5% a year, rent 3.5% a year, spare cash earning 4.6% a year, selling costs of 2.8%, compared over 30 years.

    Your scenario

    Open Rent vs Own on this scenario

    https://tool.adjiebrotots.com/rentvsownhouse/#load&v=1&qs=perth/house-2br&propertyPrice=800000&rentAmount=700&setupCost=4.4&why.setupCost=WA%20transfer%20duty%20on%20$800,000%20%28about%20$32,300%29%20plus%20conveyancing%20and%20inspections&ownOngoingCost=7500&why.ownOngoingCost=Council%20and%20water%20rates,%20insurance%20and%20upkeep%20on%20an%20$800,000%20house,%20about%200.9%25%20a%20year&note=Assumed%20Perth,%20November%202026,%202-bedroom%20house

    Open the link to see the result.

    Open this scenario
    • Your figures stay yours. Anything you state goes in as you said it; correct any assumption and the AI sends a new link.
    • Checked before you see it. The skill's script checks every input's name, range and choices before the AI sends the link, so it opens the scenario listed.
    • The tool shows what the AI chose. When the link opens, a banner lists each value the AI set and why, with an Undo back to your own inputs.

    Ready to try it?

    Download the skill Read the guide Open the tool