Q.: My sister is partially disabled, so her income is fairly low. Her credit is good, but she doesn’t earn enough to qualify for a conventional mortgage. Are there any special loan programs that help disabled people get a home loan?

A.: Millions of disabled people across the United States have similar problems when it comes to getting a mortgage. Even the most able-bodied buyer can have trouble saving for a down payment and qualifying for a loan, but it’s extra tough for folks whose earning power is limited by a disability and who have medical expenses that gobble an unusually large portion of their income.

Fortunately, several lenders and nonprofit organizations can help. Perhaps the largest and most comprehensive nationwide program designed specifically for borrowers with disabilities is operated by the Federal National Mortgage Assn., or Fannie Mae.

One of Fannie Mae’s most popular loan plans, called “Community HomeChoice,” provides help to low- and moderate-income people with disabilities and also to able-bodied people who have a family member with a disability. Eligible borrowers don’t have to meet the more rigorous down payment and earnings standards imposed on traditional buyers, which makes getting a home loan much easier.

Fannie Mae doesn’t loan money directly to buyers, but instead operates its various programs through thousands of banks and other financial institutions across the country. To find a lender that makes HomeChoice mortgages in your area, call Fannie Mae at (800) 732-6643 or go to www.fanniemae.com on the Internet.

The U.S. Department of Housing and Urban Development also provides lots of help for borrowers with disabilities. Contact the HUD regional office nearest you or go to www.hud.gov/groups/disabilities.cfm on the Internet.

Q.: You recently advised some prospective home buyers that wood-roof shingles that are splitting could indicate that the wood is beginning to dry out and that all sorts of problems could develop. We also are considering making an offer on a home with a wood roof, but the shingles are actually curling upward toward the sky instead of cracking or splitting. What’s the problem?

A.: A cracking or splitting roof is bad enough, but a roof that’s beginning to curl – whether it’s made of wood or some other material – can be even worse.

Curling is often a sign that a roof is not only drying out, but that the shingles themselves might be of very low quality. Shingles with excessive curling don’t provide any protection against wind-driven rain or other harsh weather, which in turn can lead to massive leaks, rot or even health-threatening mold or mildew problems.

Considering such potential troubles, I’ll repeat the advice I gave to that earlier letter-writer: If you want to make an offer on the property, make sure it’s contingent on your obtaining a satisfactory report from a company that specializes in roof repairs. The report might help you to negotiate a lower price with the seller if a lot of work needs to be done, or alternatively cancel the offer and get your deposit back if the seller refuses to make any concessions.

Q.: Several weeks ago, you wrote that the largest freestanding building in the world is the 1,667-foot-tall Taipei 101 office tower and shopping complex in Taiwan. I beg to differ: The tallest building is the CN Tower in Ontario, Canada, which was built in 1975 and is 1,815 feet high. If it’s any consolation, I have been reading your column for years, and I believe this is the first time you’ve made a mistake!

A.: You might think I’m “splitting hairs,” but I’m not quite ready to cop to a “mistake” just yet.

At 1,815 feet, Canada’s CN Tower is indeed taller than the project in Taiwan. But according to the authoritative Council on Tall Buildings and Urban Habitat in Chicago, a structure is not considered a building unless it provides a substantial amount of office or residential space.

The CN Tower is a communications tower – essentially a large, glorified antenna – that doesn’t provide any significant space in which people can work or live. Therefore, it does not qualify as a “building” in the eyes of the CTBUH. This means that the Taiwan project, though shorter, is still the world’s tallest building because it provides space for thousands of workers and shoppers.

To split hairs even further, the tallest man-made structure of all is actually the Petronious oil-and-gas drilling platform in the Gulf of Mexico. Operated by Texaco and opened five years ago, it’s nearly 2,000 feet tall – but most of it is underwater.