Who specifically(by name) has overall responsibility for the
design,construction, and repair of Postal facilities

Hello natie and thank you for your question.

The person who has overall responsibility for the design,
construction, and repair of Postal facilities is:

Mr. Rudolph K. Umscheid
Vice President Facilities
Facilities Services Division
4301 Wilson Boulevard
Suite 300
Arlington, VA 22203-1861
Tel: (703) 526-2727
Fax: (703) 526-2740
E-mail: rumschei@email.usps.gov

Also see:

"Expansion, Relocation, Construction of New Post Offices" 
"Vice President, Facilities."
http://www.usps.com/news/2000/press/frr.htm

If we have a look at the "Five-Year Strategic Plan of the United
States Postal Service for the Fiscal Years 2004-2008" we see that
Rudolph K. Umscheid, is responsible for facilities of the US Postal
Service.  His contact details are: (and amazingly, I managed to find
his email address!)

"Mr. Rudolph K. Umscheid
Vice President Facilities
Facilities Services Division
4301 Wilson Boulevard
Suite 300
Arlington, VA 22203-1861
Tel: (703) 526-2727
Fax: (703) 526-2740
E-mail: rumschei@email.usps.gov"
http://www.gsa.gov/gsa/cm_attachments/GSA_BASIC/RealEstateWorkplaceContactDirectry_R2OD5D_0Z5RDZ-i34K-pR.doc

"Rudolph K. Umscheid, Vice President, Facilities"
http://www.usps.com/strategicdirection/_pdf/FiveYearPlan2004-2008.pdf

"Facilities Information Systems Listing"
http://www.usps.com/foia/majorsys/facili_2.htm

"A list of post offices in need of work should be ready in about a
month, said Rudolph Umscheid, vice president of facilities."
http://federaltimes.com/index.php?S=2135746

Thank you for your question, and if you need any clarification of my
answer do not hesitate to ask before rating my answer.

Very best regards

THX1138

Search strategy included:
"us postal service" facilities
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