At a minimum $2/sq. foot...( on average $2.60-$6/sq.' )....Prep should be over 50% of the work and depending on the exterior materials, consider that sanding, scraping, filling, caulking and masking is VERY labour intensive -before the first coat can even be done. You then are usually going over the entire house 3x more - first w primer and a quality, pro painter will always then do at least two coats of colour...if window trim or a second colour for accents such as features like porches, doors, and garage is involved - the labour for those has to be factored in and finally the cost of paint and prep material -including any scaffolding or cherry picker extensions that may need to be rented to reach spots beyond the reach of ladders. (Scaffolding platforms can end up being much cheaper on a lrg. Project in time saved for painting more than just the small area you can cover on a ladder before it has to moved and set up all over again )... Exteriors vary considerably from the simple aluminum siding w very little prep and just a pressure washer, to a complicated mix of materials such as wood+stonE/brick/stucco and endless amounts of detailed gingerbread trim...a professional contractor is also factoring into his price the insurance for his crew members, something that you should NOT hire somebody without just to save a few dollars!! Especially with two-story homes w steep roof pitches, hard to reach areas that involve safety equipment and working high off the ground.
One thing I can definitely NOT advise you to do is agree to an hourly rate for such a lrg. (or complicated) job that is dependent on weather.
Never agree to pay in this manner for something that takes many days/wks to complete.
An experienced exterior house painting crew WILL be able to accurately estimate how many hrs. The job will take to complete plus or minus for any unexpected or additional jobs added on by the homeowner, if they don't manage this appropriately that it is NOT your problem, and is the company's cost to absorb. (Guaranteed their estimating ability will improve considerably on future jobs if you stand firm on a set price agreement) This also saves you keeping track of workers' hours, but you should allow a small cushion for any extras that may have been overlooked, or come up for other reasons such as renovations, changes in original plan. Agree on one third down, and do not pay final third till the very last touch-up and clean-up has been completed, all equipment is removed and your house (including details like anything that had to be removed and reinstalled ) returned to normal.
This ensures that workers are not taking their time (excessively ) on the job and that they stay professional in their goal to completion so that you aren't living w a long, drawn out, process and paying people to work at their leisure. Accompany the contractor on the estimate walk-around and ask for exact details of his process and what is included to make sure your expectations are matched before agreeing on the set amount, including paint quality, bad weather back-up plans and how many hrs./day people will be working. Finally, choose a month or (two is best) during the year where you will be most likely to not have rain/snow/extreme humidity, as this is the biggest downside (after poor prep) to your paint job not curing well (after completion) and of course during, will extend the time it takes to complete your house!!