Buying a house with mold

Read the report for the water

A home inspector will note visible growth, staining and moisture readings. What you want to know is why. Efflorescence on basement block points to seepage. Dark sheathing in the attic points to bath fans or air leaks. Stains on ceilings point to roof or plumbing leaks. A fresh coat of paint on one basement wall, in an otherwise unpainted basement, deserves a question.

Ask the seller

• Has the basement ever taken water, and when?
• Any insurance claims for water or mold?
• Any remediation done? If so, by whom, and is there a New York clearance report?
• When was the sump pump replaced, and is there a backup?
• Do the bath fans vent outside?

A clearance report from a past job is worth asking for by name. Under Labor Law section 947, a licensed assessor issues one after checking the work, and it's the closest thing to proof that the job was finished.

Get it priced before you close

If there's more than about 10 square feet of growth, a licensed mold assessor can write a remediation plan with a cost estimate during your inspection window. That plan gives you something concrete to negotiate with, whether it's a price cut, a credit, or the seller doing the work under the plan before closing. Fixr's national figure for basement mold removal is $1,500 to $4,000; your plan will be more specific.

Old Buffalo houses

Stone and early block foundations are normal in the city's older neighborhoods; the oldest ZIPs in our table are Elmwood Village, Upper West Side (Grant-Ferry), Allentown and Lower West Side, Downtown (south) and the First Ward, Hamlin Park and Masten. A dry stone basement is fine. A wet one can usually be managed with gutters, grading, a sump and a dehumidifier. Look at how the downspouts drain, whether the soil slopes toward the house, and whether stored things against the walls have water lines on them.