Annual property taxes are increasing by $346, to $10,534, for a single-family home with the town’s median assessment, $1,071,750, based on the rate approved by the Board of Selectmen last week. The board voted during its meeting Tuesday to set this fiscal year’s tax rate at $11.65 per $1,000 of assessed value, up from last year’s rate of $11.40. The new figure would increase the median property’s taxes by 3.4 percent if its owner qualifies for the town’s occupancy residential exemption, according to Gary McCabe, Brookline’s chief assessor. Most owners of single-family homes in town qualify for the exemption, he said. Selectmen also voted to raise the commercial tax rate from $18.58 to $18.97, which would raise taxes on the median commercial property by $1,116 a year.