21 Degrees Portsmouth

Energy efficient upgrades in Portsmouth and the surrounding areas.
Get in touch

Energy efficient upgrades in Portsmouth

Originally founded as Solar Voltaics and rebranded to Green Building Renewables in 2023, we evolved to become 21 Degrees in November 2024.

Whether you need a single product or the ultimate Passivhaus, your system needs to be well thought out and designed correctly. We adopt a full-circle approach to provide better performing buildings from a carbon, cost, and comfort perspective to get you the right outcome

Our specialist products and services include renewables such as solar panels and heat pumps, and energy efficient upgrades such as triple-glazed windows and doors, mechanical ventilation with heat recovery (MVHR) systems, and insulation and airtightness products. 

I was really pleased with the service and products we received from Solar Voltaics. From the initial desktop survey and quote with various options based on our needs, to the in-person survey, quick installation, friendly contractors and technical support. It’s truly hard to fault them!

Darrell de Vries - Portsmouth

Positive: Professionalism, Punctuality, Quality, Responsiveness, Value In my experience an excellent company to do business with. They provided and installed a Tesla Powerwall at my property. Their quote was competitive both on cost and availability. Placing the order was simple, and after order, the admin team kept me informed on progress, DNO approval and expected delivery date. They installed on time. The installation team ensured the installation was tidy and fully functional. 21 Degrees have, post installation, called to check all is fine. I would gladly use them again for any further solar work.

Michael Bunn - Portsmouth

From the initial enquiry to installation 21 Degrees and their team were great. After the receipt of the original quote to the scaffolding and installation all went smoothly. Very clean and efficient installation team always left the house and area of work clean at the end of each day. Would recommend.

Myles Waterman - Portsmouth

/ 3
Featured in
Change the way you think about energy