Roofing in Nepal

Nepal stretches from the hot, humid Terai plains on the Indian border to the highest mountains on earth. Its census recognises roofs of thatch and straw, galvanised iron, tile and slate, reinforced concrete, wood and mud, a range that reflects this variety of climate. The country's most celebrated contribution to roofing is the tiered Newar pagoda roof of the Kathmandu Valley.

Climate and hazards

The summer monsoon brings heavy rain to most of the country, while the high mountains have long, cold winters with snow. Nepal lies on the collision zone between the Indian and Eurasian plates and suffers frequent strong earthquakes. The 1934 Nepal-Bihar earthquake and the magnitude 7.8 Gorkha earthquake of 2015 both caused severe damage in the Kathmandu Valley, where many historic temples collapsed in 2015.

Roofing history

According to UNESCO, the blending of Hindu and Buddhist art in the Kathmandu Valley goes back at least to the 5th century CE; Changu Narayan carries one of the valley's earliest inscriptions from that time. The roots of Newar architecture are traced to the Licchavi period (about 400-750 CE), and the Durbar Squares of Kathmandu, Patan and Bhaktapur were built up between the 12th and 18th centuries, with the greatest flowering roughly from 1500 to 1800 under the Malla kings. Nepalese craftsmen, including Arniko, carried the style beyond the valley.

The valley's temples and palaces were built of fired brick in mud mortar, with timber floors, windows and roof frames, and roofs of small overlapping terracotta tiles, some decorated or covered with gilded brass. In the modern period galvanised iron sheet and reinforced concrete were added to these traditional materials, and both appear as standard categories in the census.

Traditional and vernacular roofs

• Newar pagoda roof: two or more diminishing tiled roofs on a brick shrine, each propped on carved timber struts. The Nyatapola Temple in Bhaktapur (1701-1702), with five roofs, is one of only two five-roofed temples in the valley.
• Jhingati tile roofs: small terracotta tiles (jhingati) laid in overlapping courses on timber, used on Newar temples and houses.
• Tile and slate, thatch and straw, wood and mud roofs: the traditional coverings recorded by the census in rural Nepal.

Roofing today

The national census asks about the roof of each house. In 2011 the categories were thatch/straw, galvanized iron, tile/slate, RCC (reinforced cement concrete), wood/planks, mud and other. The 2021 census published a table of households by type of roof (Table 4 of the household results).

Codes, standards and regulation

Nepal's National Building Code (NBC) is a series of documents. The seismic design code NBC 105:2020, approved by the Council of Ministers in 2020, replaced NBC 105:1994 and sets earthquake-resistant design requirements based on a seismic hazard assessment of the country, with values that vary by location. Before its revision, designers had for many years relied heavily on the Indian code. The Ministry of Urban Development is responsible for the code.

Notable roofs

• Kathmandu Valley World Heritage Site: seven monument zones, including the Durbar Squares of Hanuman Dhoka (Kathmandu), Patan and Bhaktapur, Swayambhu, Bauddhanath, Pashupati and Changu Narayan.
• Nyatapola Temple, Bhaktapur: five-roofed pagoda built for King Bhupatindra Malla, about 30 m (100 ft) high; it survived the 1934 and 2015 earthquakes.

Local roofing terms

• jhingati (Newar): small terracotta roof tile
• tundal (Newar): carved wooden bracket or strut

Sources and gaps

National census shares of roof materials and detailed accounts of mountain slate and stone roofs, the roofing industry and roofing standards: published information is limited.