A house that sold for $91.5 million tops the list of the most expensive residential real estate sales in Boulder in the past week.

During the past week, a total of 88 residential real estate sales were registered in the area, with an average price of $2.3 million. The average price per square foot was $754.

The prices in the list below include real estate sales where the title was recorded during the week of Dec. 15 even if the property may have been sold earlier.

10. $2.4 million, single-family house at 580 Pleasant Street

A detached house at 580 Pleasant Street in Boulder, has been sold. The price was $2,350,000. The house was built in 1950 and has a living area of 2,655 square feet. The price per square foot was $885. The house features 3 bedrooms and 3 bathrooms.

9. $2.4 million, detached house at 7306 Island Circle

The property at 7306 Island Circle in Boulder has new owners. The price was $2,400,000. The single-family residence was built in 1977 and has a living area of 4,930 square feet. The price per square foot was $487. The house features 4 bedrooms and 4 bathrooms.

8. $2.5 million, single-family home at 2581 Briarwood Drive

The sale of the single-family residence at 2581 Briarwood Drive in Boulder has been finalized. The price was $2,500,000. It was built in 1972 and has a living area of 1,777 square feet. The price per square foot was $1,407. The house features 4 bedrooms and 4 bathrooms.

7. $2.9 million, single-family house at 4932 Valkyrie Drive

A sale has been finalized for a single-family home at 4932 Valkyrie Drive in Boulder. The price was $2,850,000. The house was built in 1988 and the living area totals 3,802 square feet. The price per square foot ended up at $750. The house features 4 bedrooms and 6 bathrooms.

6. $3.1 million, detached house at 1719 Mapleton Ave. #A

A 1,980-square-foot single-family residence at 1719 Mapleton Ave. #A in Boulder, has been sold. The total purchase price was $3,146,500, $1,589 per square foot. The house was built in 2004. The house features 4 bedrooms and 4 bathrooms.

5. $3.5 million, single-family home at 1330 Mariposa Ave.

A 2,647-square-foot detached house at 1330 Mariposa Ave. in Boulder has been sold. The price was $3,500,000, $1,322 per square foot. The house was built in 1955. The house features 3 bedrooms and 3 bathrooms.

4. $4 million, single-family house at 2697 Fourth Street

The single-family house at 2697 Fourth Street in Boulder has new owners. The price was $4,000,000. The house was built in 2016 and has a living area of 2,661 square feet. The price per square foot was $1,503. The house features 6 bedrooms and 6 bathrooms.

3. $4.7 million, single-family home at 512 Marine Street

The single-family residence at 512 Marine Street in Boulder has new owners. The price was $4,650,000. The house was built in 1903 and has a living area of 3,238 square feet. The price per square foot was $1,436. The house features 4 bedrooms and 5 bathrooms.

2. $8.3 million, detached house at 1760 Sunset Blvd.

The property at 1760 Sunset Blvd. in Boulder has new owners. The price was $8,250,000. The single-family house was built in 2014 and has a living area of 4,502 square feet. The price per square foot was $1,833. The house features 5 bedrooms and 8 bathrooms.

1. $91.5 million, multi family at 1750 15th Street

A multi family at 1750 15th Street in Boulder, has been sold. The price was $91,500,000. The house was built in 1950 and has a living area of 123,741 square feet. The price per square foot was $739.