Short answer: the account is free forever. You pay only for the full report you hand to a client: $32 for the whole project, $19 for one module or $27 for two, tax included. With several houses a month, the Installer subscription at $129 a month costs less. Managing the subscription itself, invoices and payment methods are covered in subscription, invoices and payments.
What the free plan includes
On a free account, you work in any number of projects without entering a card. Every module is available: the heat loss calculation, heat pump sizing, radiant floor heating, heat recovery ventilation, the client form and the Algo assistant. The calculations run in full - what we limit is how much of the result you see on screen and in the PDF.
A US account sees the app in imperial units (feet, ft², °F, Btu/h, gpm) and its prices in dollars. The calculation itself stays metric, to EN standards. You can switch units in Settings or in a module's settings.
In radiant floor heating, you draw by hand on one floor; floors imported from the heat loss calculation do not count toward that limit. One AI section drawing per account is free.
A reading of your house plans, from which Algo enters the rooms, building elements, windows and doors, is not paid for separately: a reading uses the same monthly Algo limit as the chat and does not use a report. The limit grows once you buy a report and is largest with a subscription. When it is used up, Algo tells you before it starts. One reading also fills heat pump sizing and heat recovery ventilation at no extra cost. One account can run up to 10 readings per 24 hours. The details are in the heat loss calculation guide.
My library - the constructions, windows, doors, ventilation units, fittings and radiators saved on your account and available in every project - holds 5 entries in total on a free account. Only an active subscription lifts that limit; a report does not change it. If your subscription lapses, the saved entries stay, and you can add a new one once you are below the limit again.
The preview in each module shows:
- in the heat loss calculation - the building's total heat loss, the heat loss per square foot and one fully calculated room; the other rooms are covered ("Value available once the project is unlocked"),
- in heat pump sizing - the recommended heat pump with its output, supply temperature, SCOP, annual electricity use and installation cost,
- in radiant floor heating - one fully calculated room: the first one in which you draw a loop and assign the section to a room,
- in ventilation - room roles, required airflows, the supply-exhaust balance and duct velocities.
Unlocking the project adds: the full heat loss table of every room and the method details (source sizing, thermal bridges, n50, ventilation) in the heat loss calculation; the full list of matched heat pumps and the variant comparison (SCOP, annual use, installation cost) in heat pump sizing; tubing spacing, loop lengths, the manifold, the printable floor plan and the materials list for your supplier in radiant floor heating; pressure drops, pressure, the unit verdict and the printable duct plan in ventilation. In radiant floor heating, unlocking also lets you add more floors by hand.
On a free account, the first room of a new radiant floor project may be calculated with a delay - we calculate a few projects at a time, and the screen then shows a date ("The first room in this project will be calculated on ..."). An unlocked project is calculated in full right away.
On the covered room cards in the heat loss calculation, you see "Locked - unlocks on activation". Activation here means unlocking the project with a report or a subscription - nothing more. HeatAlgo has no trial period: a free account does not expire and needs no activation to calculate.
What a report unlocks: a project, or a credit
A report bought inside a project unlocks that project at once; bought outside a project, it goes to your account as a credit. One credit unlocks one project - all of its modules at once, on screen and in the PDF. You can also buy a report for one or two modules. You buy it straight for the project you pick, not as a credit, and adding another module or the whole project costs the difference in the price list while the window of the modules you hold runs. A report for one module costs $19 and for two modules $27, tax included.
A whole-project report costs $32. The price includes tax: the figure you see is the figure you pay. One purchase unlocks one project; there are no report packs. Unused credits stay on the account with no expiry - you can buy a report today and spend it six months from now.
You see the number of available credits in the account menu and on the "Billing" page under "Your plan". You buy credits with "Change plan".
How to unlock a project
In the project you want to hand to a client, click "Unlock the full report" - the button is in the project view on the "Client report" card and in every module next to the results. If you have credits, you see the "Unlock this project" dialog with the number of credits it uses; confirm with "Use a credit". If you have no credits, the purchase dialog opens with a choice: a report for the modules you pick, a report for the whole project, or a subscription.
After you unlock it, the full results are on screen right away and you download the PDF in each module. A full report gets a number in the format HA-year-code (for example HA-2026-K7M2XQ), which appears on the cover with your logo and company details. The PDF prints metric units for now, whatever units you see in the app.
The revision window: 7 days from the first download
The clock does not start at purchase but on the first PDF download. So you can unlock a project in advance and finish the calculation a week later - the window is still a full one. Each module gets its own 7 days from its own first download for revisions and new PDF versions, at no extra cost - a heat loss report downloaded on day one does not shorten the heat pump or radiant floor window. The days left are shown in the project ("Export until ...") and on the "Billing" page under "Your reports".
Two things worth knowing:
- The printable radiant floor plan has its own clock. Its 7-day window runs from the first download of the plan, separately from the report. So you can print the plan for the crew at the start and generate the report at the end of the job.
- Nothing disappears when the window closes. The project, the calculations and the full on-screen results stay, and downloaded files are yours for good. Only downloading a new PDF version closes - that needs another report or a subscription.
You buy a report for one job. Another house needs another report or a subscription - you cannot move a purchase to another project.
A subscription instead of credits
The Installer subscription covers every project on the account and has no revision window: while it is active, you edit and download reports in every project with no limit. It costs $129 a month, $103.17 a month when paid six months ahead ($619) or $89.92 a month when paid a year ahead ($1,079). Prices include tax. At prices before discounts, the monthly subscription costs less from 5 reports a month. How to buy, cancel and resume it is in subscription, invoices and payments.
For companies doing many houses a month, there is the Company plan, with an individual quote and invoicing that fits the company's process - details on the for companies page.
The setup reward
The Start page has a "Setup" card with five steps: "Who you are", "First project", "First report", "Use Algo AI" and "Secure your account". Once you finish all five, you get a discount:
- -20% on a report (the whole project, modules or an upgrade to more modules) or on the first invoice of the monthly or six-month subscription,
- -25% on the first year of the annual subscription.
The lowest price in the 30 days before the reduction, tax included:
| Product | $ |
|---|---|
| Whole-project report | $32 |
| One-module report | $19 |
| Two-module report | $27 |
| Upgrade from one to two modules | $8 |
| Upgrade from one module to the whole project | $13 |
| Upgrade from two modules to the whole project | $5 |
| Monthly subscription | $129 |
| Six-month subscription | $619 |
| Annual subscription | $1,079 |
The discount lasts 30 days and applies itself at checkout - you type no code. Every account gets it, paying ones included, but not an active subscriber. The card's sixth row, "Complete your profile" (the company name and logo on reports), is optional and does not affect the discount.
Where all this is shown
The "Billing" page (account menu, "Plan and billing") has four sections:
- "Your plan" - free account, the number of credits, or the subscription with its paid-until date,
- "Your reports" - the list of unlocked projects with the days left for revisions, separately for the report and the floor plan, and the list of projects not unlocked yet,
- "Orders" - payment and invoice history,
- "Buy" - buying credits or a subscription.
The binding price list is always on the pricing page.
A HeatAlgo report follows EN 12831-1 and EN 1264, not ACCA Manual J, and is not accepted for permits or rebates.