We do a lot of pressure washing of many different surfaces, at up to 22 metres, so far.
I am very busy and we have a full workload on all fronts.
I am in a position to walk away from a price if it is not agreed - that makes all the difference.
It is very difficult without seeing the job in person to estimate how long it will take.
I would not go on a day rate but would use a rate of £500.00 per day over a two day period - charging £1000.00 for the job but trying to finish in one day.
I would be very surprised if it took any longer than one day - possibly going back the next day to snag when you can see it dry.
You are offering to give them back the original standard of external finish that the house has not seen for quite some considerable time. They will be happy with the work as it can only look better.
You can't take the p*ss as he seems to know the score.
Good luck - and if you were thinking higher you can come and price up a couple of Sainsburys for me next year!!!
Rob