Hello,
We do 3 storey (30ft) buildings all the time and have never had a problem with our single motor systems (Clarke 1400 watt or Kärcher 1380 watt). We've developed these systems so that both the vac and generator can be handled by 1 person and will fit easily into a van alongside the WFP window cleaning systems. We do the 3 motor Kärcher systems for those who want the extra power but in all honesty have never found we've needed it and we've cleaned thousands of metres of gutters. Also with the large systems you need 2 people to get the vac and generator off the van 1 man will not be able to do it by himself!! We design our systems with ease of use, price in mind and most importantly will do the job!