def get_Cm_Af(construction):
    """
        Description	       code	    Cm_Af
        Light construction	T1	    110000
        Medium construction	T2	    165000
        Heavy construction	T3	    300000

    ..
        Copyright 2015, Architecture and Building Systems - ETH Zurich
    """
    if construction == 'light':
        cm_af = 110000
    elif construction == 'medium':
        cm_af = 165000
    elif construction == 'heavy':
        cm_af = 300000
    else:
        raise ValueError(
            'The construction should be "light", "medium" or "heavy", but equals {}'
            .format(construction))
    return cm_af
