Environment in historic house

I am currently working on the restoration of a 1930s home in
Wisconsin, USA. We have recently upgraded the existing HVAC system.
My question concerns RH levels. I had always been told that optimum
RH in a historic house was 50% with a temperature between 65 and 70
degrees Fahrenheit year round. The project architect feels this RH is
too high and will infiltrate the plaster and begin to rot the wall
studs. What should we do? Any suggestions for sources concerning
this topic?

Christine Cross


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                  Conservation DistList Instance 14:35
                Distributed: Thursday, December 21, 2000
                       Message Id: cdl-14-35-009
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