Center for Environmental Building & Design

Reinventing the Traditional Mongolian Home to Help Solve a Health Crisis | UNICEF USA

Energy and Comfort of Mongolian Ger (Yurt), Ulaanbaatar, Mongolia - 2017-18

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 (2009).

Working with the Mongolian non-profit GerHub  (, we are auditing the comfort and energy use of a selection of buildings in the ger district of Ulaanbaatar to understand their thermal behavior and to identify opportunities to improve both their comfort and energy performance. We have also assembled a ger at the Pennovation Center, where we can study its behavior in more detail and more readily test improvements. The immediate result of the project will be an auditing protocol for Mongolians interested in evaluating and improving the energy performance of their ger. The longer term project is to collaborate with the many parties in Mongolia working to develop improved ger, better adapted to their fixed, urban locations.

The first phase of the research has been made possible with the generous support of Penn Global's Global Engagement Fund.

Project Approach

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 (2013).”

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 (Millenium 2013). Real energy savings and pollution reduction can only be achieved by making residents more comfortable with less fuel consumption.

The first phase of the project is to monitor and evaluate the thermal properties of the ger. Monitoring package have been installed in four ger, accompanied by a weather station. Another ger has been shipped to Philadelphia, where it is being assembled at the Pennovation Center, where multiple sensors can be installed to understand the complex thermal behavior of this very simple structure.

The ger is deeply bound up with Mongolian nomadic culture and identity, so any projected improvements will be developed in close consultation with ger residents and carefully balance the symbolic value of the ger with the metropolitan conditions of the ger district.

Team Members & Roles

Center for Environmental Building + Design, University of Pennsylvania

Bill Braham, Professor and Director, will serve as principal Investigator for the project, coordinating team work, data analysis, and the writing of reports and publications.

Evan Oskierko-Jeznacki, PhD student, will install and troubleshoot the monitoring systems, develop the hygrothermal models of the ger, and supervise the work of the graduate student from the Environmental Building Design program, who will prepare documents describing the ger and their thermal environments.

Michael Henry will serve as an expert consultant on monitoring protocols and analysis of the thermal behavior of the ger.

KieranTimberlake | Architecture, Planning, Research

Billie Faircloth will work with the team to understand the comfort and thermal regime of the ger and to strategize improvements and interventions, drawing on the deep resources at KieranTimberlake to develop proposals for ger and the ger district.

Stephanie Carlisle will serve as project manager for the KieranTimberlake team, drawing on her experience living in Mongolia for a year.

GerHub, Ulaanbaatar, Mongolia

Badruun Gardi is CEO of GerHub, a non-profit active in the ger district, is the key collaborator for the project. He will help identify ger for monitoring and review proposals as they are developed.


Kim Dupont-Madinier is an architect on leave from Certainteed Research working in the ger district for a year on a Fullbright scholarship. She has installed monitoring equipment for temperature and heat flow in four ger in the district.

Laura H Kwong is a PhD candidate in Civil Engineering at Stanford, working with a design team testing improvements to the sealing of the cap of the ger. She has installed and is testing indoor air quality of the four ger.

Bryan Paris is an Air Monitoring Data Analyst & QA/Toxics Supervisor for the Louisville Metro Air Pollution Control District, who is working with the US State Department to improve the monitoring of pollution in Mongolia.

Forrest Meggers is an Assistant Professor at the Princeton University School of Architecture & Andlinger Center for Energy + the Environment. He is assisting with some of the monitoring protocols, especially of the asymmetrical radiant environment within the ger.