Energiesprong: Retrofit in a Week

Energiesprong — Dutch for "energy leap" — treats retrofit as manufacturing rather than construction. Insulated facades and roofs are made off-site to a laser survey of the existing building, craned into place in days, and paired with a heat pump and solar so the home generates roughly as much energy as it uses. Crucially the work comes with a long-term performance guarantee, which is what lets housing associations pay for it out of the residents' existing energy costs rather than a rent rise. Around 11,000 Dutch homes have been converted, with over 10,000 more across Europe and North America and roughly 1,000 a year now being done in the Netherlands. Retrofitted homes use about 80% less energy. Residents mostly talk about being warm.