Scott is correct that you can't refuse to rent to families with children under the age of six; however, you could rent through word of mouth and/or friends and family to place someone in the house that does not have children under that age. I have not suggested that you have a tenant sign any papers waiving liability, or anything of the sort. You have legal right to rent to adults, or adults with children over the age of six. Furthermore, even if you did delead your home it is likely that lead based paint was used on the entire project at some time, and children are just as likely to get poisoned by eating the dirt in the yard that closely surrounds the home. Before you spend the potential 10's of thousands of dollars to delead your home, I would hire the services of a trained professional in the field to determine the extent of the lead, and the accuracy of your test. Store bought kits should not be used as the prime indicator of lead based paint in the home as they are notoriously inaccurate. It should be understood that I am not telling you to circumvent the law. There are many homes being rented that have known lead paint. I am just giving you a real world example of how you might accomplish your goal without the expense, and still comply with MA laws. If you can afford to delead it is always your best option, and there are some deleading abatement programs out there. Eventually you may wish to transfer the property, and deleading is almost inevitable at that point. What year was your house built? If after 1978 it is unlikely that lead paint was used. Also, what rental period would you be wanting? Summer rentals typically do not have to be deleaded. All points in these answers should be considered carefully.
If a child is lead poisoned by lead hazards where the child lives and the owner has not complied with the Lead Law, the owner is legally responsible. An owner cannot avoid liability by asking tenants to sign an agreement that they accept the presence of lead paint. Nor can an owner refuse to rent to families with children under six years of age in order to avoid Lead Law responsibilities. This is discrimination, and it is illegal under the Lead Law and federal and state fair housing laws. Complying with the Lead Law is the best protection an owner has from liability and a child has from lead poisoning.
If you are considering renting your home, I am assuming that you would like the income to pay for some type of expense (perhaps the mortgage)? The cost to de-lead the home can be very expensive, and would be counter productive to the benefits of renting your home. Instead of taking all this preventative measure, I would just state in your rental ad that you are unable to rent to families with children under the age of 6 years old. The law only requires you to de-lead below that age, and only again, if the stay is longer than 100 days. This is a simple solution to your problem. I would however, paint over the exisiting lead paint. Check for chipping, as this is the most common cause of lead poisoning due to exposure to the old paint.
You should probably also consult with your insurance agent and a real estate attorney to review your liability if there is any questions. Remember just removing the windows unless done properly will only further spread the lead paint dust potentially over the interior of the rest of the property & outside. Lead can also be found in putty, plaster, adhesives and other common building materials. And just as over the holidays proved there are still items out there with lead paint that we buy new and don't know about.
That's the Massachuetts Health & Human Services section on Lead
The EPA is coming out with more stringent guidelines as to de-leading. Seek professional guidance. Rick Reibstein is a good resource. Check out: https://www.vtbar.org/Images/Journal/journalarticles/Summer%