Mortgage Notes Payable

ESS does not have any indebtedness as all debt is incurred by the Operating Partnership. Mortgage notes payable consist of the following as of December 31, 2016 and 2015 ($ in thousands):



	2016			2015
Fixed rate mortgage notes payable	$	1,911,699		$	1,925,985
Variable rate mortgage notes payable ⁽¹⁾	279,782			289,092
Total mortgage notes payable ⁽²⁾	$	2,191,481		$	2,215,077
Number of properties securing mortgage notes	61			64
Remaining terms	1-30 years			1-31 years
Weighted average interest rate	4.3		%	4.4		%

The aggregate scheduled principal payments of mortgage notes payable at December 31, 2016 are as follows ($ in thousands):



2017	$	82,796
2018	301,575
2019	576,954
2020	693,868
2021	51,584
Thereafter	441,313
	$	2,148,090

⁽¹⁾

Variable rate mortgage notes payable, including $257.3 million in bonds that have been converted to variable rate through total return swap contracts, consists of multi-family housing mortgage revenue bonds secured by deeds of trust on rental properties and guaranteed by collateral pledge agreements, payable monthly at a variable rate as defined in the Loan Agreement (approximately 1.2% at December 2016 and 1.2% at December 2015) plus credit enhancement and underwriting fees ranging from approximately 1.0% to 1.3%. Among the terms imposed on the properties, which are security for the bonds, is a requirement that 20% of the apartment homes are subject to tenant income criteria. Principal balances are due in full at various maturity dates from May 2025 through December 2046. Of these bonds $20.7 million are subject to various interest rate cap agreements that limit the maximum interest rate to such bonds.


⁽²⁾	Includes total unamortized premium of $50.8 million and $64.8 million and reduced by unamortized debt issuance costs of $7.4 million and $8.0 million as of December 31, 2016 and 2015, respectively.

For the Company’s mortgage notes payable as of December 31, 2016, monthly interest expense and principal amortization, excluding balloon payments, totaled approximately $7.4 million and $2.5 million, respectively. Second deeds of trust accounted for zero of the $2.2 billion in mortgage notes payable as of December 31, 2016. Repayment of debt before the scheduled maturity date could result in prepayment penalties. The prepayment penalty on the majority of the Company’s mortgage notes payable are computed by the greater of (a) 1% of the amount of the principal being prepaid or (b) the present value of the mortgage note payable which is calculated by multiplying the principal being prepaid by the difference between the interest rate of the mortgage note and the stated yield rate on a specified U.S. treasury security as defined in the mortgage note agreement.