Home Improvement Loan Modernization Act of 2014 - Amends the National Housing Act to specify the premium charge paid by a financial institution to insure any loan, advance of credit, or purchase of obligations representing loans and advances of credit it makes to finance certain home improvements for both existing single-family and multifamily structures.

Sets the initial premium at 2.75% of the original insured principal obligation, with annual premium payments not to exceed 1.5% of the remaining balance.

Limits any premium charges to the minimum amounts necessary to maintain a negative credit subsidy for the insurance program.

Increases the maximum obligation that may be insured for improvements to: (1) an existing single-family dwelling from $25,000 to $42,000; and (2) an existing multi-family structure from $60,000 to $101,888, with an average amount of $20,378 (currently $12,000) per family unit.

Directs the Secretary of Housing and Urban Development (HUD) to develop a method of indexing to increase these dollar amount limitations annually, based on the Consumer Price Index for all urban consumers (CPI-U) computed by the Bureau of Labor Statistics (BLS).

Allows an increase in these dollar amount limitations also by up to 150% if at least half of the amount will be used for energy conserving improvements or the installation of solar energy systems.