How to configure the intermediate output directory in C#

You could try to do this (don't forget that there are Debug and Release sections which will be used depending on what type of build you are targeting):

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    ...
    <BaseIntermediateOutputPath>..\build\obj</BaseIntermediateOutputPath>
    <IntermediateOutputPath>$(BaseIntermediateOutputPath)$(Configuration)\</IntermediateOutputPath>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    ...
    <BaseIntermediateOutputPath>..\build\obj</BaseIntermediateOutputPath>
    <IntermediateOutputPath>$(BaseIntermediateOutputPath)$(Configuration)\</IntermediateOutputPath>
</PropertyGroup>

Do this like Microsoft:

  <PropertyGroup>
    <IntermediateOutputPath Condition=" '$(PlatformName)' == 'AnyCPU' ">$(BaseIntermediateOutputPath)$(Configuration)\</IntermediateOutputPath>
    <IntermediateOutputPath Condition=" '$(PlatformName)' != 'AnyCPU' ">$(BaseIntermediateOutputPath)$(PlatformName)\$(Configuration)\</IntermediateOutputPath>
  </PropertyGroup>

I've used:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>$(OBJDIR)\$(SolutionName)\bin\$(Configuration)\</OutputPath>
    <BaseIntermediateOutputPath>$(OBJDIR)\$(SolutionName)\obj\$(Configuration)\</BaseIntermediateOutputPath>
    <IntermediateOutputPath>$(BaseIntermediateOutputPath)\</IntermediateOutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
</PropertyGroup>

(In Visual Studio 2012 Beta, FWIW), and it works fine.

The OBJDIR on my machine points to E:\BuildOutput.