User Damian's example

SConstruct

import os
dbgfilelist = [
    'concrt140d.dll',
    'msvcp140d.dll',
    'vccorlib140d.dll',
    'vcomp140.dll',
    'vcruntime140d.dll'
]

relfilelist = [
    'concrt140.dll',
    'msvcp140.dll',
    'vccorlib140.dll',
    'vcomp140.dll',
    'vcruntime140.dll'
]

# Now create dummy files
os.makedirs("bin", exist_ok=True)
for f in dbgfilelist+relfilelist:
    with open("bin/%s" % f, 'w') as of:
        of.write(f)


vars = Variables()
vars.AddVariables(EnumVariable('BUILDTYPE', help="Build type DEBUG or RELEASE",
                               default='RELEASE', allowed_values=("RELEASE", "DEBUG")))

thisenv = Environment(tools=[], variables=vars,
                  INSTALLDIR="#/Install", BINDIR="#/bin")

thisenv['INSTALLDIR'] = '$BINDIR/../interfaces/binaries/x64'


if thisenv['BUILDTYPE'] == 'DEBUG':
    for cn in relfilelist:
        thisenv.Execute(Delete(thisenv.File('$INSTALLDIR/%s'%cn)))
    
    rel_install =thisenv.Install(thisenv['INSTALLDIR'], ['$BINDIR/%s'%x for x in dbgfilelist])

    Default(rel_install)
else:
    for cn in dbgfilelist:
        thisenv.Execute(Delete(thisenv.File('$INSTALLDIR/%s'%cn)))

    dbg_install = thisenv.Install(thisenv['INSTALLDIR'], ['$BINDIR/%s'%x for x in relfilelist])
    Default(dbg_install)