Restoration and climate adaptation of church ruins, Holla, Norway

The Holla church ruin at Ulefoss in south-eastern Norway, a 13th-century church that has stood as a ruin since 1867, required renewed conservation because increasing precipitation and more frequent frost-thaw cycles were degrading masonry repaired in earlier, less climate-resilient campaigns, particularly from the 1920s.

The 2020 restoration aimed to preserve the ruin for the long term under a changing climate, make it publicly accessible, improve its physical condition, and interpret its history for visitors.

1920s concrete joints were replaced with hydraulic lime joints, which are less susceptible to moisture and weathering damage than the original lime mortar (unsuitable given the ruin has no roof); the wall capping was replaced with cast fibre-reinforced concrete slabs designed to slide at the wall top and avoid cracking as temperature and ground conditions change; soil within 25 cm of the walls was replaced with gravel to limit rainwater soaking and fire risk; and native vegetation was planted around the site to reduce erosion. A path and interpretive signage were added, and the masonry is now monitored every two years, with minor flaws repaired before they cause structural damage. The public and volunteers were involved throughout, and the site remained open to visitors during the works.

The Norwegian Directorate for Cultural Heritage (Riksantikvaren) reported a total project cost of about NOK 14.5 million (approximately EUR 1.4 million), of which private donations contributed NOK 2.8 million (approximately EUR 0.3 million). The restoration is reported to have increased visitor numbers to the area, with associated benefits for local businesses.

Success factors identified include designing for long-term climate resilience with materials allowing targeted point-to-point repairs, and strong stakeholder and volunteer involvement that fostered community ownership of the site. Limiting factors included the cost and fundraising effort required, some local opposition on environmental and heritage-integrity grounds, and the need for continued long-term maintenance and monitoring.