Check it for free.Pay when you're sure.

Calculate heat loss, size a pump and draw underfloor heating by hand on one floor - floors imported from the heat loss calculation do not count towards that limit. One AI section drawing per account is free. On screen you see the building totals plus one fully worked room per module (one loop in underfloor heating) and the recommended pump. Locked on preview: the remaining rooms, the details and calculation method, the pump variant comparison, the underfloor heating loop spacing and lengths, the printable underfloor floor plan, the underfloor bill of materials, and adding another floor by hand. A report for the chosen modules or the whole project unlocks it. My library, the constructions, windows and doors saved on your account, is separate: a free account holds up to 5 entries in it, an active subscription lifts that limit, and a report does not change it.

One unlock covers the whole project across every module - heat loss, pump sizing, underfloor heating and heat recovery ventilation together, with your branding and a report number. For underfloor heating you get the report, the scaled printable floor plan and the bill of materials for the wholesaler with the coil cutting plan - each a separate PDF, downloadable together as one ZIP file. The report and the bill of materials download on a phone too. For heat recovery ventilation you get the report and the scaled printable duct layout. You can also buy a report for one or two modules of a project, and pay only the difference to add a module or the whole project while their window runs.

The clock starts on your first download, not at purchase - so you can buy ahead and work the project up a week later. Each module gets its own 7 days, counted from its own first download - further PDF versions at no extra cost, and editing is never limited. Downloaded files are yours to keep, and the project and its calculations stay visible in your account always. A report is bought for one job - the next house needs another report, or a subscription.

At around 2 reports a month or more, the subscription is cheaper than buying reports one by one.

A purchase made on this site is settled by Stripe, and Stripe is the seller: the tax for your country is already in the price, and Stripe issues the invoice carrying our business name and the product details. Buying for a company? Enter your tax ID in the payment form and it appears on that invoice. The for-companies route stays open for negotiated engagements - there we are the seller and issue a VAT invoice ourselves.

On this site you pay by card, or through Apple Pay, Google Pay and Link. BLIK and Przelewy24 are not available on this route. Bank transfer is arranged through the for-companies route.

A purchase on this site cannot be completed from the countries our payment provider restricts: Ascension Island, China, Cuba, Iran, Kosovo, North Korea, Russia, Syria, Tristan da Cunha. From anywhere else it works normally.

See the for-companies page - that's where you'll book a call about rollout matched to your project volume.