Heddal Stave Church is a hybrid. Its nave borrows from two traditions: the towering central plan of the Borgund type, with its dramatic vertical interior, and the long arcaded nave of the Kaupanger group, which stretches the building lengthwise. The result is a structure that manages to be both tall and deep, its chancel extending through six free-standing masts into a space that feels more like a corridor than a room. But the most telling detail is on the facade. In older stave churches, pagan dragon heads occupy the highest positions on the roof, with Christian symbols placed below. At Heddal, the arrangement is reversed: Christian symbols sit at the more elevated level. The church was built after Christianity's influence had spread throughout Norway, and the decorative hierarchy records that shift. The portals, which in earlier churches served as thematic boundaries between pagan exterior and Christian interior, here lean fully into the new faith. The older ambiguity is gone.

Beneath 17th-century decorative paint on the walls of Heddal's chancel and nave, restorers in the early 2000s found the remains of medieval wall paintings. Between 2008 and 2010, the distempered paintings were painstakingly refurbished to their original medieval designs, revealing a style similar to the wall paintings at the Torpo Stave Church, evidence of an artistic connection between workshops in different parts of southern Norway. The church's post-medieval history is a study in institutional indifference. After the Reformation reached Norway in 1536-1537, the building fell into serious disrepair. In 1723, during the Norwegian church sale, the King sold it, along with hundreds of other churches across the country, to private owners in order to pay debts from the Great Northern War. The new owner was responsible for upkeep, a responsibility that went largely unmet. By the mid-1800s, the building was in dangerous condition.

In 1848, the architect Johan Henrik Nebelong began a major rebuilding of Heddal Stave Church. When it was finished in 1851, the interior had been transformed into something closer to the Empire style fashionable in 19th-century Scandinavia, a look completely at odds with a medieval wooden church. The restoration was strongly criticized, and for good reason. This was one of the first major restorations of a medieval building in Norway, and neither Nebelong nor the newly established Society for the Preservation of Ancient Norwegian Monuments had much understanding of stave church construction. The rebuilding introduced moisture problems and fungal damage that would plague the structure for the next century. A second, more sympathetic restoration was carried out in the 1950s, stripping away much of Nebelong's work and attempting to return the interior to something closer to its medieval character. The lesson of Heddal's two restorations became a cautionary example in Norwegian heritage preservation: good intentions without proper knowledge can cause as much damage as neglect.

In 1814, Norway wrote its constitution. The process required elections, and each church parish served as a constituency. Heddal Stave Church, along with more than 300 other parish churches across the country, became a polling station for the country's first national elections, where locals chose electors who would later select representatives for the constitutional assembly at Eidsvoll. The church has carried this dual identity ever since, serving simultaneously as a place of worship and a site of secular significance. Unlike many surviving stave churches, which have been decommissioned and preserved as museums, Heddal remains an active parish church. Weddings are common. Services are held regularly. The church is open to tourists during the summer season, and its proximity to the town of Notodden makes it one of the more accessible stave churches in Norway. The heating system, which keeps the interior at a steady 5 degrees Celsius through the cold months between October and May, reflects the ongoing challenge of maintaining an 800-year-old wooden building that is still expected to function.