A contribution to the Search for Extra-Terrestrial Intelligence
 (SETI) is made by searching for astro-engineering products of
 advanced civilizations.
 A photometric survey, covering 5 wavelength bands, of 72 or 59 old
 main sequence stars (autumn or spring launch) shall be performed
 in order to assess infrared excesses compatible with the presence of
 large astro-engineering products like Dyson spheres that emit a
 blackbody spectrum of several hundred K temperature. This survey
 serves to identify candidates for Dyson spheres which subsequently
 shall be considered for more detailed observations in a separate
 follow-up programme either with ISO (detailed spectral investigation)
 or in another regime of the electromagnetic spectrum from another
 observatory.
 Additional 10 or 15 objects (autumn or spring launch) which show
 infrared excesses in the 12 or 25 microns IRAS measurements shall be
 investigated in more photometric detail at 13 wavelengths. This
 programme serves to reveal ultimate indication of the existence of
 Dyson spheres or otherwise.
 The usage of ISO is crucial for the success of the observation
 programme as only ISO currently offers the high sensitivity,
 especially with ISOPHOT, that is needed to identify a several hundred
 K blackbody spectrum flux excess generated by an astro-engineering
 product superimposed on a several thousand K blackbody background
 spectrum of the host star.
 The observation programme makes also an important contribution to the
 knowledge of developed main sequence stars in the infrared, thus
 supplementing existing ISO GT and OT observing programmes.