Center for Environmental Building & Design

  • Weather Station at Test Ranch

    Weather station at the Ger Test Ranch

  • Test ger at "ger ranch"

    Six test ger at "ger ranch"

  • Monitoring equipment in test ger

    Monitoring equipment in test ger, including globe thermoment and ground temperature sensor

  • Final Report

    Designing the 21st Century Ger: Final Report

Designing the Ger of the 21st Century - 2018-19

Ulaanbaatar, Mongolia

"I was born in a ger, I grew up in a ger, I got married in a ger. I have never lived in a house. I love my ger.” (Tagtokhbayar Tuvaan)

Working with UNICEF and the Mongolian non-profit GerHub, a team from PennDesign’s Center for Environmental Building and Design and KieranTimberlake Architects is auditing the thermal performance of six improved ger at a test site and five occupied ger in the ger district of Ulaanbaatar. The team has also assembled a ger at the Pennovation Center, where they can test additional improvements.

Ger are the traditional, tent-like dwellings of the Mongolian herder nomads (called Yurts in Russian). With the steady urbanization of Mongolia since the 1960s, former nomads have been settled in legal, semi-formal “ger districts” at the perimeter of cities, and roughly 60% of the residents of the capital city live there in a combination of ger and self-built rigid frame houses. Ulaanbaatar is the coldest capital city in the world, and almost all of the 200,000 ger area households burn unrefined coal, making it one of the most polluted cities as well. Beginning in 2009, the World Bank and Millennium Challenge Corporation funded a program to provide more efficient stoves to the region, a program which has mitigated coal use and pollution to some degree, however there is little information on thermal characteristics of the ger construction itself, either in terms of energy use or the connection to interior comfort, clothing, or lifestyles.

The climatic conditions in the region are extreme. According to the Millennium Challenge Corporation, “Mongolia has an extremely harsh winter climate, and mid-winter temperatures in Ulaanbaatar, the capital, can drop to as low as minus-40 degrees. Nearly half of all Mongolians live there, the coldest capital city in the world and the world’s second-most air polluted city." Ger are only kept warm in winter with a steady supply of fuel (wood and coal). They are a lightweight form of construction with little capacity to retain any heat, so the thermal properties of the envelope construction and air sealing are critical to their energy use. The question of interior comfort is equally important and the interior temperatures are limited by the leakiness of the envelope and the firing cycles of the stoves. With the installation of the new stoves “rebound effects” have already been noted: occupants maintain higher interior temperatures once the new stoves are installed, effectively spending the savings of the more efficient stoves. Real energy savings and pollution reduction can only be achieved by making residents more comfortable with less fuel consumption.

"Ger Test Ranch"

A group of six ger have been assembled at test site on the outskirts of UlaanBaatar. These have been deployed to test a variety of improvements and to validate diagnostic techniques that can be used as part of auditing protocols. There is one standard, unimproved ger, three ger with insulated floors developed by KieranTimberlake, one ger for testing improvments to the door and toono (top ring), and finally, an "everything ger" with improvements to all the components.

Occupied Ger

Five occupied ger in the ger district have been instrumented to better understand the thermal performance in actual use.


Billie Faircloth
Stephanie Carlisle
Connor Cook
Chris Macneal
Badruun Gardi,
Enkhjin Batjargal
Munkh-Orgil Lkhagva
Purevsuren Norjinbat

William W. Braham
Evan Oskierko-Jeznacki
Max Hakkarainen


William W. Braham, Associate Professor of Architecture
Michael C. Henry, Adjunct Professor of Architecture
Stephanie Carlisle, Lecturer