Description
The Centre for Alternative Technology (CAT) is an environmental charity near Machynlleth in mid-Wales that teaches low-carbon building, eco-renovation and renewable energy through free information sheets, short courses and postgraduate degrees.
It was founded in 1973 on a disused slate quarry and opened its visitor centre in 1975. CAT is a registered charity (no. 265239), funded by its members, donations and legacies. Its free information service covers natural building materials, low-energy buildings, planning permission for eco-building projects, whole-house retrofit, wall insulation, windows and airtightness, and describes its advice as independent and impartial. One of its sheets describes its own WISE building.
Short courses run on site; those listed for the coming months included Low and Zero Carbon Buildings (14 to 18 December 2026), Renewables for Households on micro hydro and wind turbines in November 2026, and Reedbeds and Compost Toilets (6 February 2027). Its Graduate School offers master’s degrees, among them Sustainability and Adaptation and an MArch in architecture; applications for 2027 entry open later in autumn 2026. The Zero Carbon Britain hub helps councils and community groups plan cuts in emissions. The site was open for pre-booked visits only when checked, such as courses, groups and its B&B.
Strengths
- The free information sheets cover the practical questions of an eco-renovation, from insulating walls to airtightness and planning permission.
- Courses are taught on a site where low-carbon buildings, compost toilets and renewable energy have been tried out for decades.
- It is a charity with no products to sell, funded by members, donations and legacies.
Weaknesses
- The centre is in rural mid-Wales, and when checked it was open only to visitors who had booked a course, a group visit or a stay.
- The course listing shows no prices, so the cost of a course isn’t clear at a glance.
- The free information is general, not advice on a particular house, and there is no advice line on the pages read.
Who it is for
Self-builders, homeowners planning a deep renovation and building professionals in the UK who want to learn low-carbon methods, on a short course or a master’s degree.
Sources
- CAT: home, about us, free information service, short courses, Graduate School courses, getting to CAT (checked November 2026)
- Woodlands.co.uk: Centre for Alternative Technology, a good visit for woody people
- Visit Mid Wales: Centre for Alternative Technology short courses
- National Library of Wales: Centre for Alternative Technology archive



