makes such guaranteed loans (collectively referred to as “SBA loans”). The guaranteed portion of these loans is typically sold in the secondary market depending on market conditions. When the guaranteed portion of an SBA loan is sold, the Company retains the servicing rights for the sold portion. During the six months ended June 30, 2021 and 2020, loans were sold resulting in a gain on sales of SBA loans of $633,000 and $67,000, respectively
The Company’s factoring receivables are from the operations of Bay View Funding whose primary business is purchasing and collecting factored receivables. Factored receivables are receivables that have been transferred by the originating organization and typically have not been subject to previous collection efforts. These receivables are acquired from a variety of companies, including but not limited to service providers, transportation companies, manufacturers, distributors, wholesalers, apparel companies, advertisers, and temporary staffing companies. The portfolio of factored receivables is included in the Company’s commercial loan portfolio. The average life of the factored receivables was 36 days for the first six months of 2021, compared to 38 days for the first six months of 2020. The balance of the purchased receivables was $47.1 million at June 30, 2021, compared to $41.9 million at June 30, 2020 and $47.2 million at December 31, 2020.
The commercial loan portfolio, excluding PPP loans, increased $3.8 million, or 1%, to $557.7 million at June 30, 2021, from $553.8 million at June 30, 2020 and increased $2.0 million, or 0.36%, from $555.7 million at December 31, 2020. Commercial and industrial (“C&I”) line usage was 27% at June 30, 2021, and June 30, 2020 and 28% at December 31, 2020.
In addition, the Company had $286.5 million in PPP loans at June 30, 2021, compared to $324.6 million at June 30, 2020 and $290.7 million at December 31, 2020.
The Company’s CRE loans consist primarily of loans based on the borrower’s cash flow and are secured by deeds of trust on commercial property to provide a secondary source of repayment. The Company generally restricts real estate term loans to no more than 75% of the property’s appraised value or the purchase price of the property depending on the type of property and its utilization. The Company offers both fixed and floating rate loans. Maturities for CRE loans are generally between five and ten years (with amortization ranging from fifteen to twenty five years and a balloon payment due at maturity), however, SBA and certain other real estate loans that can be sold in the secondary market may be granted for longer maturities.
The CRE owner-occupied loan portfolio increased $29.6 million, or 5%, to $583.1 million at June 30, 2021, from $553.5 million at June 30, 2020, and increased $22.7 million, or 4%, from $560.4 million at December 31, 2020. CRE non-owner occupied loans increased $16.3 million, or 2%, to $742.1 million, compared to $725.8 million at June 30, 2020, and increased $49.0 million, or 7% from $693.1 million at December 31, 2020. At June 30, 2021, 44% of the CRE loan portfolio was secured by owner-occupied real estate.
The Company’s land and construction loans are primarily to finance the development/construction of commercial and single family residential properties. The Company utilizes underwriting guidelines to assess the likelihood of repayment from sources such as sale of the property or availability of permanent mortgage financing prior to making the construction loan. Construction loans are provided only in our market area, and the Company has extensive controls for the disbursement process. Land and construction loans decreased ($8.9) million, or (6%), to $129.4 million at June 30, 2021, compared to $138.3 million at June 30, 2020, and decreased ($15.2) million, or (10%), from $144.6 million at December 31, 2020.
The Company makes home equity lines of credit available to its existing customers. Home equity lines of credit are underwritten initially with a maximum 75% loan to value ratio. Home equity lines of credit decreased ($4.8) million, or (4%), to $107.9 million at June 30, 2021, compared to $112.7 million at June 30, 2020, and decreased ($4.0) million, or (4%), from $111.9 million at December 31, 2020.
Multifamily loans increased $29.2 million, or 17%, to $198.8 million, at June 30, 2021, compared to $169.6 million at June 30, 2020, and increased $32.4 million, or 19%, from $166.4 million at December 31, 2020.
From time to time the Company has purchased single family residential mortgage loans. Residential mortgage loans increased $110.9 million, or 117%, to $205.9 million at June 30, 2021, compared to $95.0 million at June 30, 2020, and increased $120.8 million, or 142% from $85.1 million at December 31, 2020. The increase in residential mortgage loans at June 30, 2021, compared to June 30, 2020 and December 31, 2020, was the result of the purchase of two single