Ladakh is a high-altitude cold desert, situated across the greater Himalayas. During extremely cold
winters, keeping livable spaces warm remains a priority for any family. Ladakh witnesses consistently sunny
days even in peak winters and this abundant solar energy can be harnessed for heating homes.
In recent times, Ladakh experiences migration of many families from village to the Leh town for either
jobs, education or tourism. One such settlement is in Saboo-thang village. This is an example of unplanned
development, done at such a pace that every new house coming up is averse to traditional knowledge and life choices.

Our client is an award-winning self-made businesswoman, running a trekking company operated only
by women. This house is for her family of two adults and a child. The eco-friendly local dry composting toilets are required on both floors, squatting type with a dual manure chamber on upper and a western seat with a barrel system on ground floor.

This earthen house design revolves around the core factors of passive-solar heating (PSH) and
traditional planning. It is designed to stay warm in winter (without additional heating) and cool in summer
through ventilation; providing running water throughout the year, which is rare in Ladakh. Thus, keeping
interiors at around +12 °c, while outdoors may be at -25 °c.

Key technical features:

The house is oriented to the solar South to gain more winter Sun. Ancillary functions along the North
act as a thermal buffer. Central area is shared by kitchen, dining and seating space like a traditional ‘Chansa’, wrapped around traditional 4 wooden column design ‘Ka-(b)zhi’.

Both rammed earth (ground floor) as well as adobe wall (first floor) construction techniques are used
with insulation. The outer and inner walls are 60 cm and 45 cm thick respectively. Earth provides thermal lag in walls and straw-clay provides natural insulation for the flooring and roofing. External doors are insulated sandwich-panelled wooden doors with double rebates to cut heat loss. The adobe walls have repurposed army mattresses as insulation. Geo-tensile mesh within rammed-earth, and timber/RCC ties in stone and adobe masonry are used for earthquake resistance. Thermal breaks are designed within the wall systems wherever thermally conductive materials like RCC or stone are used.

The passive solar south façade of bedrooms is made with a Trombe wall system which has (2+1) triple
glazing, 20 cm wide cavity and black painted concrete brick wall as thermal energy storage. This captures
radiation from low winter Sun and heats interior through convection (via hot air current in the cavity) and
conduction throughout the day. Together, limecrete floor and South walls made of concrete form thermal
mass, which radiates heat even at night.

The attached greenhouse to the Chansa captures solar radiation and warms up living space via
convection. The greenhouse remains above 0 °c even in winter, so can be used to grow vegetables, and it
helps regulate humidity indoors in dry weather. The interior and exterior walls are finished with hand-made plasters with earthen materials and traditional touch.