Privacy policy

Plain English, no legal fog. Here's exactly what data we collect, why, and what happens to it.

Who we are

Knowwatt (knowwatt.uk) is an independent UK home energy calculator and guide site. If you have questions about this policy, contact us at the email address on our affiliate disclosure page.

What data we collect

Calculator inputs

When you use our calculators (solar, heat pump, battery, insulation, etc.), the inputs you enter — postcode, property type, roof orientation, energy usage — are processed entirely in your browser. This data never leaves your device. We don't store, transmit, or have access to your calculator inputs.

Analytics

We use Plausible Analytics (plausible.io) to understand which pages are visited and where visitors come from. Plausible is privacy-focused: it uses no cookies, collects no personal data, and does not track you across sites. We see aggregated numbers (e.g. "200 people visited the solar calculator this week"), not individual visitor data. Plausible is EU-owned and GDPR-compliant by design.

Quote request forms

If you submit a quote request form (e.g. on the insulation calculator), you voluntarily provide your name, email, phone number, postcode, and house number. This data is shared with our partner LeadsDoWork, who pass it to up to 4 local installers in your area so they can contact you with quotes. We do not store this data on our own servers. By submitting the form, you consent to being contacted by these installers. You can withdraw consent at any time by contacting us or the installers directly.

Installer interest form

If you're an MCS-certified installer and register interest in our directory, you provide your company name, contact name, email, postcode coverage, and services. This data is submitted via Formspree (formspree.io) and delivered to our email. We use it solely to contact you about the installer directory. We don't share it with third parties.

Cookies

Knowwatt uses cookies in two ways:

Essential cookies: we store your cookie consent preference so we don't ask you again on every visit. This cookie contains no personal data — just whether you accepted or declined advertising cookies.

Advertising cookies (with your consent): if you accept cookies via the consent banner, Google AdSense may set cookies to serve relevant display advertisements on our guide pages. These cookies allow Google to track which ads you've seen, prevent repetition, and measure ad effectiveness. Google may use information about your visits to this and other websites to provide ads relevant to your interests. You can opt out of personalised advertising at any time via Google's Ad Settings.

If you decline cookies, no advertising cookies are set and you will see non-personalised ads (or no ads at all). You can change your preference at any time by clicking "Cookie settings" in the footer.

Our analytics (Plausible) do not use cookies.

Affiliate links

Some links on this site are affiliate links. When you click one, a tracking parameter in the URL tells the destination site that you came from Knowwatt. If you make a purchase within the tracking window, we earn a commission. We don't receive your personal data through this process — we see only that a conversion occurred, not who you are. Full details of our affiliate partnerships are on our affiliate disclosure page.

Third-party services

We use the following third-party services, each with their own privacy policies:

• Plausible Analytics (plausible.io) — privacy-focused analytics, no cookies, no personal data
• Google AdSense (google.com/adsense) — display advertising on guide pages only, sets cookies with your consent
• Formspree (formspree.io) — processes installer interest form submissions
• LeadsDoWork (leads.work) — processes insulation quote requests and connects you with installers
• Awin (awin.com) — affiliate tracking network for product links
• Cloudflare (cloudflare.com) — hosts the site and provides security

Your rights under UK GDPR

Under UK data protection law, you have the right to:

• Access the personal data we hold about you
• Request correction of inaccurate data
• Request deletion of your data
• Object to processing of your data
• Withdraw consent at any time
• Lodge a complaint with the Information Commissioner's Office (ico.org.uk)

In practice, the only personal data we might hold is your installer interest form submission (in our email). If you want it deleted, let us know and we'll remove it.

Data retention

Calculator inputs: not stored at all. Analytics: Plausible retains aggregated data indefinitely but collects no personal data. Form submissions: retained in our email until the purpose is fulfilled or you request deletion. Affiliate tracking: managed by Awin and the respective advertisers under their own retention policies.

Children

Knowwatt is not directed at children under 16. We don't knowingly collect data from children.

Changes to this policy

We'll update this page if anything changes. The date at the bottom tells you when it was last revised.

Last updated May 2026. Updated to include display advertising and cookie consent.