I should note here that there is currently a house for sale in western Washington that would be excellent for someone with MCS. It has all hardwood floors that are very old (as in, the finish is completely worn off), the house is old but has no musty or moldy odor, it's at the end of a culdesac, it has a back porch, garage is not attached (no exhaust fumes make their way to the house) there's been no improvements on it, it's uphill of other houses so the wind is better to dissipate pollution, has a fairly large yard...the house is just amazing for anyone with chemical sensitivities, and I can hardly bear the thought of a regular person buying it and ruining it with toxic stuff. So if anyone is interested, please PM me.
When selecting houses, you definitely want to go for as little carpeting as possible, due both to chemicals and dust mites. There's a big difference in the way curtains collect dust than the way a carpet collects and stores dust so that it's never really clean. If the comfort of a carpet is important to you, I strongly recommend investing in rugs, ideally organic, unbleached, undyed. Rugs can be washed and thus cleansed much more thoroughly than carpet ever can be. And as a bonus, you take them with you when you move so you get to hang on to that investment, unlike carpeting. If they could be tossed in the washing machine that's even better....much easier than vacuuming so you're more likely to be able to do it often.
If propane triggers a reaction then you definitely want to stay away from it. That doesn't necessarily mean you must get a house without it, simply that if you do then you won't get to use those appliances and you'll probably want to have the supply shut off to the house to make sure there's none of that stuff at all anywhere near you.
That being said, realize that not all gas powered appliances are propane....in the city most of them are natural gas. (I only recently learned the difference, lol). It's possible you don't do well with propane but are fine with natural gas, however the only way to know this is to test it for yourself.
You definitely want no new paint or other fix-ups if you can at all avoid it. Foreclosure houses are great in this regard, as the bank can't be bothered to expend the effort. One home my family recently looked into even had a pile of dog poop in the corner - no kidding! That's the kind of house you want to look into, one where no one's bothered to clean with toxic chemicals or put new paint on the walls or anything.
Edit: Note that there's a kind of natural vinyl, Marmoleum, that some people do fine with. It's made of all natural materials. It isn't something I'd personally choose to use, but that is another possibility, and if you find a house that has Marmoleum flooring I'd give it ia chance.
The older the better,
as long as you don't smell any mold or mildew. If you smell either, get out. It isn't worth it. Houses about 20 years old or so tend to be lacking a vapor barrier, which is a good thing....that means moisture in the walls has a chance to escape, greatly reducing the likelihood of mold.
There are, however, some things you can do to improve a house. The first course of action is ozone. I'm not talking about an ozone air purifier that only emits low doses, I'm talking about an ozone
generator capable of producing a lethal concentration of ozone into its surroundings. You can either buy or rent one. You set it up and leave the house while it does its job and then wiat to enter until the levels are safe enough. The ozone breaks down the chemicals and outgasses new stuff, basically "aging" it very quickly. It will also kill every single dust mite in the environment. Of course, the allergic reaction is usually to their feces, so that might not be immediately helpful, but you can see how it would be handy.
Mold will also be killed with this method, however, if there's mold inside the walls the ozone won't get to it. So again, stay away from houses that smell like mold.
Another thing you can do is some home improvement of your own. AMC safecoat has sealants for trying to seal in chemicals that you can use on walls, carpets, wood, etc. In my experience success varies. I still would strongly recommend against carpets due to the dust mites. LIme or clay plaster is being sold as a paint alternative, and though I have no personal experience with those options I know that if tolerable, covering paint with them should neutralize the issue of pain chemicals outgassing into the room.
Due to the dust, you want to avoid a house with a heating duct system. Those things collect dust and then blow it all over the house. In-floor radiant heat is ideal, other radiant heating options are good, anything that doesn't depend on blowing air. Of course, if that isn't possible, you can make do by adding a whole house filtration system or not using it at all and covering up all the ducts.
Houses on busy roads usually have more dust.
A back porch/verandah/screened room/gazebo is very helpful for airing out chemical stuff outside.
WIth dust mite allergies (ask me how I know
) cleaning the house regularly and thoroughly is very important. You want to keep in mind whether or not a house would be easy to clean, and especially size. Smaller houses are generally easier.
It's a good idea to take a look at how well-kept the lawn is, and especially the neighbors' lawns as well. If they are immaculate, that probably means your neighbors use chemical fertilizers and herbacides to keep them that way and living there could turn into an MCS nightmare. I have a friend who knows. You want neighbors who are low maintenence about their landscaping.
Also pay attention to who has chimneys nearby, and if possible ask a neighbor about wood burning in the area. Unfortunately, the worst stuff is caused my human error and not inherant properties of wood burning. Nevertheless, I can't tolerate any smoke at all. As for you, I have to say if you come accross a house with a masonry heater (also known as a Russian stove, a Swedish fireplace, a Finnish fireplace, and other things) then that's a big bonus in my eyes. They are not like a normal fireplace. I'll keep this short and just say you light a fire that only burns for an hour or two and the heat radiates in the house for the next 12-24 hours.
This page has a breakdown of some things chemically sensitive people should look for when buying a house.
3CFIDS, I'm so sorry to hear about your family's illness and experience.