Staggered Lightweight Timber Frame Alternative to Traditional Bhutanese Ekra Wall

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F25%3A00384990" target="_blank" >RIV/68407700:21110/25:00384990 - isvavai.cz</a>

Result on the web

<a href="https://www.researchgate.net/publication/395392065_Lightweight_Timber_Frame_Walls_in_Context_of_Bhutan_and_Staggered_Lightweight_Timber_Frame_Alternative_to_Traditional_Bhutanese_Ekra_Wall#fullTextFileContent" target="_blank" >https://www.researchgate.net/publication/395392065_Lightweight_Timber_Frame_Walls_in_Context_of_Bhutan_and_Staggered_Lightweight_Timber_Frame_Alternative_to_Traditional_Bhutanese_Ekra_Wall#fullTextFileContent</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Staggered Lightweight Timber Frame Alternative to Traditional Bhutanese Ekra Wall

Original language description

The staggered timber frame ekra wall system is a modern adaptation of a traditional Bhutanese wall construction method. In a typical ekra wall, a heavy post and beam timber frame is infilled with a bamboo lattice and coated with mud plaster. While culturally significant, this method often lacks sufficient seismic resilience and thermal insulation. The improved system introduces staggered vertical timber studs, which alternate on the interior and exterior faces of the wall. This configuration reduces thermal bridging and improves insulation performance. Instead of a bamboo infill woven parallel with the load-bearing timber frame, the system uses diagonally woven split bamboo, which provides additional in-plane bracing and structural stability without altering the traditional appearance of the frame. Infill materials such as mud or hempcrete plaster are applied to both sides of the bamboo lattice, increasing thermal mass and airtightness and thermal insulation properties. The frame itself is designed to resist vertical and lateral loads, with mostly nail joinery for ease of prefabrication and on-site assembly. This hybrid solution maintains the cultural identity of traditional ekra construction with exposed timber elements while addressing modern requirements for seismic performance, energy efficiency, and material optimization. Two prototype houses are currently under construction using this method. The load-bearing timber frame consist of columns/studs of 50x100 mm in cross-section, top and bottom plate of 200x50 mm, trimmers at both sides of the window opening of 200x50 mm and decorative horizontals of 50x50 mm in cross-section from the exterior side of the wall. Total width of the wall structure is 200 mm, studs are placed 50 mm of the wall axis on centre alternative on both sides. Diagonally woven bamboo strips are between studs on the centre of the wall with 100 mm thick layer of hempcrete casted also on the centre of the wall.

Czech name

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Czech description

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Type

G_funk - Functional sample

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

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Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Internal product ID

2025_Alternative ekra wall_v1

Numerical identification

D1.1_Paro_Hemp_Prorotype

Technical parameters

The sample is used by the user of the prototype building Timber used = blue pine Wall test sample size = 5275 x 2440 mm (length x height) Stud size = 50 x 100 x 2340 mm (width x height x length) Stud spacing = 440 mm on axis (average) Top and bottom plate size = 200 x 50 x 5275 (width x height x length) Average volume of installed timber per 1 m length of wall = 0.3719 m3

Economical parameters

Average price of timber per 1 m length of wall = 53.3 USD (25% less than traditional bhutanese timber frame)

Application category by cost

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Owner IČO

68407700

Owner name

České vysoké učení technické v Praze / FSv / katedra konstrukcí pozemních staveb

Owner country

CZ - CZECH REPUBLIC

Usage type

V - Výsledek je využíván vlastníkem

Licence fee requirement

Z - Poskytovatel licence na výsledek nepožaduje v některých případech licenční poplatek

Web page

https://www.researchgate.net/publication/395392065_Lightweight_Timber_Frame_Walls_in_Context_of_Bhutan_and_Staggered_Lightweight_Timber_Frame_Alternative_to_Traditional_Bhutanese_Ekra_Wall#fullTextFileContent