<?xml version="1.0" encoding="utf-8" ?>
<configuration>

  <configSections>

    <section name="log4net"
      type="log4net.Config.Log4NetConfigurationSectionHandler,
            log4net"
    />

    <!-- NHibernate Section -->
    <section
        name="hibernate-configuration"
        type="NHibernate.Cfg.ConfigurationSectionHandler,NHibernate"
        />

    <sectionGroup name="applicationSettings"
...
    </sectionGroup>

  </configSections>

  <log4net>

    <!-- A1 is set to be a ConsoleAppender -->
    <appender name="A1" type="log4net.Appender.ConsoleAppender, log4net">
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%-4timestamp [%thread] %-5level %logger %ndc - %message%newline" />
      </layout>
    </appender>

    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender, log4net">
      <file value="logs/log4net.log" />
      <appendToFile value="true" />
      <rollingStyle value="Size" />
      <maxSizeRollBackups value="10" />
      <maximumFileSize value="100KB" />
      <staticLogFileName value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%-4timestamp [%thread] %-5level %logger %ndc - %message%newline" />
      </layout>
    </appender>

    <!-- Set root logger level to DEBUG and its only appender to A1 -->
    <root>
      <level value="ALL" />
      <appender-ref ref="A1"/>
      <appender-ref ref="RollingFileAppender"/>
    </root>

  </log4net>

  <!-- NHibernate Configuration -->
  <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
  </hibernate-configuration>

  <applicationSettings>
...
  </applicationSettings>

</configuration>

NHibernate.Cfg.Configuration config = new NHibernate.Cfg.Configuration();