How HouseWorkbench works
Every tool on this site follows the same workflow, from the measurements you bring to the plan you leave with. Understanding that workflow once makes every individual project tool faster to use.
1. Everything runs in your browser
There is no account, no server-side calculation, and no database behind this site. The page you load contains the calculation logic itself, and it runs on your device the moment you change an input. That is a deliberate architecture choice, not just a privacy feature: it means the site has no meaningful cost to run at any traffic volume, and it means your project details are never exposed to a breach, a subpoena, or a change in someone else's data-retention policy, because they were never transmitted in the first place.
2. Measurement to plan
A project tool starts by asking for the facts a tape measure, a product label, a plan, or a recent quote can normally supply in a couple of minutes: dimensions, openings to subtract, the products you are considering, and the prices you have found for them. The tool flags anything missing or out of range before it produces a result, so you find out you are missing a measurement before you are staring at a number you cannot trust, not after.
3. Transparent assumptions, not hidden ones
Once a tool has what it needs, it shows the calculation, not just the final number. That means the quantities that fed into a result, any waste allowance applied, and any planning assumption used are visible and, where it makes sense, editable. If a tool's method depends on a manufacturer's stated coverage or yield, that number comes from the product label you enter, not a hidden site-wide average.
4. Package rounding and leftover coverage
Materials are sold in fixed units, cartons, gallons, rolls, bags, stock lengths, not the exact decimal quantity a project needs. A tool converts a required quantity into whole purchase units and shows the leftover coverage that rounding creates, because that leftover often changes which of two options is actually cheaper once you buy in real packages instead of comparing raw unit prices.
5. Product-label verification stays with you
A tool can calculate from the numbers you give it, but it cannot verify a product's installation instructions, a manufacturer's spacing or clearance requirement, a local code or permit rule, or a site condition specific to your property. Where that verification matters to whether a plan is safe to act on, the tool names it explicitly as the next thing to check, rather than assuming it away.
What a plan cannot decide for you
A quantity or budget plan is not an installation guide, a structural calculation, or a permit determination. Product instructions, local building requirements, and your specific site conditions can all change what is actually safe or appropriate to build, and a qualified professional's review is sometimes the correct next step. This site tells you when that kind of verification applies to a project; it does not perform it.
6. Carrying values across tools
A value you enter on one tool, like your default waste allowance, can prefill automatically on another tool that uses the same fact, so planning several projects does not mean retyping the same assumption each time. That prefill lives only in your browser's local storage and is never transmitted anywhere; you can always overwrite a prefilled value on any page, and it never blocks a tool from working correctly from a blank field.
Common questions
Does anything I enter leave my browser?
No. Every calculation runs in your browser using JavaScript that ships with the page. Nothing you type, including measurements, product choices, or prices, is sent to a server, because there is no server for it to go to. Analytics, where enabled, records anonymous page views only and never your inputs or results.
Why does a plan ask for a product-specific coverage number instead of assuming one?
Coverage, stock length, and package yield vary by manufacturer and by product line, and a generic average would make the resulting purchase plan wrong for your actual materials. Product-label numbers you enter are treated as authoritative for your project; the site never substitutes a generic default without telling you.
What happens if I clear my browser data?
Any values this site prefilled for you from an earlier tool live only in your browser’s local storage. Clearing your browser data, switching devices, or using a private window clears that prefill, but every tool still works correctly from a blank field, since it does not depend on a prior visit.
What does the ft/in ↔ m/cm switch in the header actually convert?
It converts every measurement you type, length, width, area, and volume fields, between US customary and metric units, so you can enter a room measured with a metric tape measure directly. It does not convert a result’s purchase units: paint is still sold by the gallon and lumber by the linear foot in the US regardless of how you measured your room, so results and product-label coverage numbers (the figures printed on a can or box) stay in the units those products are actually sold and labeled in.