Sustain (SustainSolutions)

About us

Sustain, operating as SustainSolutions, is a Danish company specialised in climate-optimising existing buildings, based in Kongens Lyngby, Denmark. The company advises on, designs, executes, and finances energy renovations of existing houses, apartment buildings, and other properties across all of Denmark, and specialises in serving housing associations ('boligforeninger'), municipalities, companies, institutional investors, and private property owners — an unusually complete 'A to Z' offering that covers everything from initial energy screening through project development, execution, and financing of the resulting works.

Sustain's stated purpose is that an energy-improved home or property reduces energy consumption, delivering both CO2 and financial savings; the company notes that buildings account for roughly 40% of CO2 emissions, framing existing-building renovation as a major lever for climate impact. Its energy renovation services typically involve replacing heating sources, optimising a building's thermal envelope (insulation, windows, airtightness), renewing technical installations and lighting (including LED conversion), and installing renewable and sustainable energy sources such as solar panels and heat pumps — all intended to lower energy consumption, extend a building's usable lifespan, and improve indoor climate for occupants.

A notable feature of Sustain's model is its financing partnerships: the company works with the Danish pension fund PKA and Denmark's Green Investment Fund ('Danmarks Grønne Investeringsfond') to finance and invest directly in the green transition of existing buildings, rather than relying solely on clients to self-fund renovation work. Sustain is based at Orgelfabrikken, Lyngby Hovedgade 102, 2800 Kongens Lyngby, Denmark (CVR no. 32337740), and can be reached at +45 72 20 08 66. The company maintains a LinkedIn profile and publishes English- and German-language versions of its site.