Privacy & Cookie Policy

Effective: 6 September 2026  ·  Data Controller: VentCalc Ltd  ·  ICO Reg: CSN6168768

This policy explains how VentCalc Ltd (“VentCalc”, “we”, “us”) collects, uses, and protects personal data in accordance with the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018 (DPA 2018).

1. Data Controller

VentCalc Ltd is registered in England and Wales (Company No. 17123275). Our ICO registration number is CSN6168768.

For all data-protection enquiries contact us at legal@ventcalc.co.uk or for general enquiries at info@ventcalc.ai.

2. Data We Collect & Why

Payment data: We never store, process, or see payment card numbers, CVVs, or bank details. All transactions are handled directly by Stripe, Inc. under their own PCI-DSS-compliant infrastructure. We retain only a Stripe transaction reference and the plan purchased.

3. Third-Party Data Processors

We have reviewed each processor under the UK Transfer Risk Assessment (TRA) framework and have executed Data Processing Agreements (DPAs) as required by Art. 28 UK GDPR.

4. AI Processing & Your Data

VentCalc uses artificial intelligence to assist with floor-plan analysis, ventilation sizing, and calculations. You acknowledge that:

• AI outputs are generated automatically based on user inputs and embedded assumptions.
• There is no guarantee of accuracy, completeness, or suitability for any specific project.
• AI interpretation of uploaded drawings may be incomplete or incorrect.
• All outputs are indicative only and intended for early-stage feasibility and design support.

Building data you upload is processed in-memory only for the duration of your session and is not retained on our servers after your session ends. Operational metadata — including your drawing filename, analysis outcome, and account identifier — may be transmitted to our internal monitoring systems (see Section 3) for service quality and error-tracking purposes.

We use OpenAI (GPT-4o) to analyse image-based drawings and Anthropic (Claude) to analyse PDF drawings. Both providers have been configured with opt-out of training on user data to protect your intellectual property and confidential building information.

Important: VentCalc outputs are indicative and intended for early-stage design support only. Final design responsibility remains with the project team, engineer of record, or suitably qualified consultant. See our Terms & Conditions for full details of our liability position.

5. Cookie Policy

We use the following cookies and similar technologies:

Google Consent Mode v2

We implement Google Consent Mode v2 on the marketing site (ventcalc.ai). If you click Reject all, Google Tag Manager is not loaded at all — no scripts, pixels, or identifiers are set. If you click Accept all, Google Analytics and Tag Manager are activated and the consent state is updated to “granted” for all storage types.

You can change your preference at any time by clearing your browser's local storage (key: vc_consent). The banner will re-appear on your next visit.

Microsoft Clarity (authenticated app only)

We use Microsoft Clarity on the authenticated application (app.ventcalc.ai) to understand how professionals navigate the tool — session replays and aggregated heatmaps help us identify usability issues. Clarity is not used on the marketing site (ventcalc.ai). Our legal basis is Legitimate Interests (Art. 6(1)(f) UK GDPR): improving the service for authenticated, professional users. You may opt out of Clarity session recording via Microsoft's privacy settings.

6. Your Rights Under UK GDPR

• Access (Art. 15): Request a copy of personal data we hold about you.
• Rectification (Art. 16): Ask us to correct inaccurate data.
• Erasure (Art. 17): “Right to be forgotten” — request deletion of your data.
• Restriction (Art. 18): Ask us to pause processing in certain circumstances.
• Portability (Art. 20): Receive your data in a structured, machine-readable format.
• Object (Art. 21): Object to processing based on legitimate interests.
• Withdraw consent (Art. 7(3)): Where processing is consent-based, withdraw at any time without affecting prior lawful processing.

To exercise any right, email legal@ventcalc.co.uk. We will respond within one calendar month (UK GDPR Art. 12).

7. Data Retention

• Analytics data: retained for 14 months in Google Analytics (default GA4 setting), then automatically deleted.
• Account data: retained for the lifetime of your account plus 30 days after deletion request.
• Transaction records: retained for 7 years to comply with UK HMRC requirements.
• Building / calculation data: processed in-memory only; not persisted after session.

8. Security Measures

• All data in transit is encrypted via TLS 1.2+.
• Hosting on Vercel with automatic HTTPS and DDoS protection at the edge.
• No raw payment data ever reaches our servers (Stripe tokenisation).
• In-memory AI processing — calculation inputs are not written to disk.
• Access to any persisted data is restricted to authorised personnel only.

9. Children's Privacy

VentCalc is a professional B2B tool intended for engineers and construction professionals aged 18 and over. We do not knowingly collect data from anyone under the age of 18. If you believe a minor has submitted data to us, contact legal@ventcalc.co.uk and we will delete it promptly.

10. Right to Complain

You have the right to lodge a complaint with the Information Commissioner's Office (ICO) if you believe we have mishandled your personal data:

• Website: ico.org.uk
• Helpline: 0303 123 1113

We would always prefer to resolve concerns directly — please contact us first at legal@ventcalc.co.uk.

11. Changes to This Policy

We may update this policy to reflect changes in law or our practices. Material changes will be communicated via a banner on the website and/or email to registered users. The “Effective” date at the top of this page indicates when the current version was last revised.