Privacy, in plain English.
Solar.day collects what it needs to give you an answer, sells nothing, and you can have anything deleted with one email.
Who's responsible
Solar.day is run by Mat Moakes, trading as Green But Not Heard. That makes me the data controller. Postal address: 4th Floor, 18 St. Cross Street, London EC1N 8UN. Email: mat@greenbutnotheard.com.
ICO registration: ZC252862.
What this site collects, and why
| What | Why | Legal basis | How long |
|---|---|---|---|
| WhatThe first half of your postcode (e.g. BS1). Only the first half is stored, even if you type the full thing. | WhyTo place you in a sunshine and pricing region. | Legal basisProviding what you asked for. | How longWith your assessment, below. |
| WhatYour quiz answers: roof, outdoor space, energy use, tenure, budget band, how long you plan to stay, and your result. | WhyTo produce your result and, without your name, to improve the tool and see which routes come up most. Every completed assessment is stored, whether or not you leave an email. | Legal basisProviding what you asked for, and my legitimate interest in improving the tool. | How longUp to 24 months. |
| WhatYour email address, only if you ask for your result by email. | WhyTo send your result. If you tick the optional box, to email you when the numbers behind your result change. | Legal basisProviding what you asked for; consent for the updates. | How longUntil you ask me to remove it. |
| WhatAnalytics (only if you accept on the cookie banner): pages viewed, device and browser type, approximate location. | WhyTo see which pages get read. | Legal basisYour consent. | How longGoogle keeps it for up to 14 months. |
Research participants
If you arrived through a Prolific study, your participant ID is stored with your assessment so I can match it to the survey. Study data is used only for the research described in your participant information sheet. To withdraw, email me with your Prolific ID.
A note on what lands in my inbox
When an assessment completes, or someone leaves an email, a summary (postcode area, property type, result) is emailed to me so I can see the tool is working. That mailbox is Google Workspace.
Who else handles your data
- Supabase: database, hosted in the EU (Frankfurt).
- Resend: sends the emails (US company, certified under the UK Extension to the EU–US Data Privacy Framework).
- Cloudflare: hosts and serves the site.
- Lovable: build platform and aggregate visit statistics using a short-lived session identifier.
- Google: Google Analytics if you accept it; Google Fonts, which your browser fetches from Google's servers; and YouTube, whose video thumbnails load on the Learn pages.
- Google Workspace: my mailbox.
Where data leaves the UK it goes to providers covered by the UK's adequacy decisions or the Data Privacy Framework, or under the UK's standard international data transfer agreement.
Cookies and similar things
Until you choose, this site sets nothing beyond what it needs to work: your answers are kept in your browser's storage so you don't lose them between pages. If you accept analytics on the banner, Google Analytics sets its cookies (_ga and _ga_*, up to two years). Decline and the site works identically. Change your mind via "Cookie settings" in the footer. Hosting keeps a session identifier for up to 30 minutes for aggregate statistics; it holds nothing about who you are.
Your rights
You can ask me for a copy of what I hold about you, ask me to correct or delete it, object to how I'm using it, or withdraw consent you've given. One email to mat@greenbutnotheard.com does any of these; I aim to reply within a week and must within a month. To complain about how I've handled your data, email me and I'll acknowledge within 30 days and tell you what I've done. You can also complain to the Information Commissioner's Office at ico.org.uk.
Children
Solar.day is meant for adults.
Changes
If this changes materially I'll update the date. Last updated: 25 September 2026.