The Dover Sun House, completed in 1948, is recognized as one of the first modern solar-heated homes.
Designed by architect Eleanor Raymond with engineer Maria Telkes, the house in Dover, Massachusetts, used sunlight collected by large south-facing panels. Heat was stored in Glauber’s salt, a phase-change material that could release heat after sunset.
The system showed that solar energy could provide useful space heating in a domestic building, not just warm water. Its experimental storage approach was innovative but technically demanding and was not widely adopted.
The Dover Sun House was solar-heated rather than photovoltaic. It did not primarily make electricity from solar cells; its central purpose was collecting and storing heat.