HomeMy WebLinkAboutB14-0269 Energy Code Compliance Form
Jake’s Drafting Service, Inc.
PO Box 774121 426 Oak Street
Steamboat Springs, CO 80477
970.879.7929 Fax 970.879.8709
e-mail jakes@springsips.com
28 July, 2014
Martin Haeberle, CBO
Town of Vail,
75 S Frontage Road
Vail, CO 81657
Ref: Chateau d-O’ex, Adam Bersin
Martin,
We would like to use section R402.1 General (prescriptive) method for code compliance with the IECC. The difficulty in using this section is determining the R-value for the log walls.
ResCheck is not very good at doing log walls as it uses the inscribed square to determine average thickness and does not use large logs.
In lieu of using ResCheck for this determination we would like to use the ICC-400-2012 “Standard on the Design and Construction of Log Homes” to determine the U-value for our log walls
and more specifically section 305 “Thermal Envelope”.
As mass walls we are required to meet an R-value of 19 for zone 7.
This house will use Lodge Pole Pine which has a specific gravity of 0.39. Log tips at the saddle notch will have a minimum diameter of 13-1/2” and a butt diameter at the saddle notch
of 17-1/2” with an average layup of 15”. We created a section of the log walls at the saddle notch and at the midpoint of the wall using the above sizes. This gives an average wall
thickness of 12.60”. See the attached wall layup diagram for reference.
Logs will be TPI certified to less than 15%.
Using Section 305.3.3 Calculation method the R-value for the proposed wall will be 19.21, meeting the prescriptive R-value for mass walls of R-19 per Table R402.1. “Insulation and Fenestration
Requirements by Component” for zone 7. See attached “Log Thermal Envelope Calculations” prepared by JDS, Inc.
All other components will meet or exceed Table R402.1.
Should you have questions or need further clarification, please feel free to contact me.
Sincerely,
James M. Henry, President
Jake’s Drafting Service, Inc.
JMH/jmh
H:\proj|MLH Bersin\BPS\ICC-400-2012.doc