These are some fantastic questions to ask and I particularly like the one that is concerned about safety for the painters. After all, if you have a large home and you’re hiring them to paint the exterior of that home then they’ll likely be on scaffolding. Because of that, you need to make sure that the contractor not only provides appropriate safety training, but has the correct liability insurance as well.
Ours was a big job. We chose to work with three colors, one of which Sang and his partner painstakingly applied to all our window trim and grids. But before the colors came the preparation. The detail and precision of their work can not be understated. Even the taping of plastic was performed with purpose, each edge a clean line. Sang inspected all phases (patching, sanding, and power washing) with great attention and after three days of intensive work, it was time for primer and paint. Sang is knowledgeable and gave us great advice on how to best use our colors. Again, he payed close attention to detail, making sure that our house looked beautiful. We are extremely pleased!
O'Neil patches shallow holes and divots with Ready Patch because it dries fast, sands smooth, and stays flexible. Deep cracks and rotten spots are best repaired with two-step epoxies, such as those made by Advanced Repair Technology. (For a step-by-step instructions, see Repairing Rot with Epoxy.) The days of using polyester auto-body fillers on wood are over. "They cure too hard," says Portland, Oregon–based painting contractor Kathleen George. "They look good at first, but then they peel away."

Complete the EPA’s Renovation, Repair and Painting (RRP) program. As of 2010, all painting contractors in the United States must be officially certified to work with lead-based paints. The purpose of the RRP program is to inform new contractors about the risks and proper safety procedures for working on properties that contain hazardous materials.[2]
The cost to paint an average size room (10X12) ranges from $380-$790, not including ceilings, trim or cost of the paint. DIY, this can cost between $200-$300. When estimating the cost, painters will start with how much paint will be required to complete the job. To know this, they first need to know the size of the area to be covered. The easiest way to calculate the size of the paintable area is to add together the length of the wall and multiply it by the width of the room from floor to ceiling. The resulting amount is the room's square footage. This total is a starting point, as it is not all paintable surface. The painters won't paint the windows and doors, for example, and they must account for ceiling trim and baseboards as well. The next step is to subtract the area of the doors and windows -- along with the square footage of the trim and baseboards -- to get an average. Then, use the same calculation (length x width) on the windows, doors, trim and baseboards, and subtract all of those numbers. The result of this equation is the square footage of the room's walls. This is your surface area number. (Painters will typically add a little square footage back in to this amount to account for extra paint, which may be required.)
So why not just paint your own home. I'm not a painter, so my wife and I take our time, buying the paint and supplies, and doing our own painting. Yes, we need to tape, and it's not perfect, but we get the satisfaction of seeing our completed work. Get the supplies, sliders for your furniture, and patience and go for it. That way YOU have control over the entire project.
My husband has been a professional painter over 30 years. He prides himself in his high level of work ethic and customer satisfaction. He stays up to date on techniques and finishes. He gives Very detail and accurate appraisals with contracts. At an alarming rate, as he starts to finish the last day or the day before, the client starts nit picking and being disrespectful towards his work when every day prior to that, they were very pleased, as he request ongoing satisfaction throughout the job. Then they don't to want pay remaining balance, bicker about final cost, or stop payment. He has a crew he has to pay whether the customer does or doesn't honor the contract as well as our own household expenses. Wasted time ,labor, money and effort lost. Now how do we fix this? Remind yourself and clients that a contract is based on honor.
Deciding which paint to use has gotten much easier now that acrylic latexes have pushed oil-based paints almost to extinction. The acrylics offer superior performance (they don't harden with age, the way oils do, so they move and breathe without blistering), they don't mildew as readily, and they emit fewer VOCs, so they comply with new air-quality regulations. They also work over both oil- and water-based primers.

Home Painter Co