Calculate for free. Pay only when you need the reports.
Complete your Part G water efficiency calculation and see your PASS or FAIL result without paying anything.
If you need professional Water Efficiency Reports and Part G Calculation Schedules afterwards, the first dwelling or plot is £20 + VAT, with additional plots from £10 + VAT each.
No subscriptions. No hidden fees.
Everything you need, without paying before you know the result
Use the calculator first. You only pay if you decide to generate professional project-specific calculation documents afterwards.
Complete the Part G water efficiency calculation and check whether the dwelling passes without entering payment details.
- Single and multiple dwellings
- Instant PASS or FAIL result
- 125 or 110 L/person/day targets
- Quick and Advanced calculation modes
- Unlimited recalculations
- No account required to start
£24 including VAT
- Water Efficiency Report
- Detailed Part G Calculation Schedule
- Project-specific calculation documents
- Suitable as supporting evidence for Building Control
- Secure PDF downloads
- VAT receipt included
Your calculated result is shown before you are asked to purchase any reports.
Simple pricing for larger residential projects.
Water Calculations supports developments containing multiple dwellings, plots and house types.
The first plot costs £20 + VAT, and each additional plot within the same project costs £10 + VAT.
You can also create different house types and assign them to the relevant plots within the development.
Start a Multi-Plot CalculationProfessional Part G calculation documents
Purchased reports are generated from your completed project specification and remain securely available within your account.
Water Efficiency Report
A clear project-specific report showing the dwelling, calculated water consumption, applicable target and final PASS result.
Part G Calculation Schedule
A detailed breakdown of the fixture specifications, individual water-use contributions and final calculation methodology.
Secure Account Access
Access purchased reports, VAT receipts and order history again from your Water Calculations account whenever required.
Why pay before you know whether the property passes?
We let you complete the calculation and see the result first. That means you can amend the proposed specification, recalculate and confirm that the dwelling meets the required target before purchasing any professional documents.
If you only need to check the design, you can use the calculator without purchasing anything at all.
Common questions about payment and reports
Everything you need to know before purchasing your calculation documents.
Is the calculator completely free?
Yes. You can complete the calculation, view the result and amend the specification without paying. Payment is only required if you choose to generate professional reports.
How much does the first report cost?
The first dwelling or plot costs £20 + VAT, which is £24 including VAT.
How much are additional plots?
Each additional plot within the same project costs £10 + VAT.
What documents are included?
Purchased projects include a Water Efficiency Report and detailed Part G Calculation Schedule. A VAT receipt is also provided.
Do I need a subscription?
No. Water Calculations does not require a monthly or annual subscription. You simply pay for the reports you choose to generate.
Are prices subject to VAT?
Yes. The first plot is £20 + VAT (£24 including VAT), and each additional plot is £10 + VAT.
Need a commercial water efficiency calculation?
Offices, schools, retail, hotels and mixed-use schemes, including BREEAM Wat 01 water consumption. Send us your drawings for a fixed-fee quote.
Check your property before spending anything.
Complete your Part G water efficiency calculation and get an instant PASS or FAIL result. Purchase professional reports only when you need them.
Start Your Free Calculation No account or payment required to start