6. Property, Plant and Equipment and Leases

Property, plant and equipment at April 30, 2017 and 2016, consists of the following (in thousands):

	2017		2016
Buildings and building improvements	$	2,646	$	2,643
Machinery, equipment and furniture		56,435		51,468
		59,081		54,111
Less, accumulated depreciation		44,268		41,797
	$	14,813	$	12,314

Depreciation and amortization expense for the years ended April 30, 2017 and 2016 was $2,610,000 and $2,456,000, respectively.

Maintenance and repairs charged to operations for the years ended April 30, 2017 and 2016 was approximately $675,000 and $593,000, respectively.

The Company leases its Long Island, New York headquarters building at an annual rent of $800,000 following the Company’s exercise of its option to renew the lease for a second 5-year period. The lease will end in January 2019. Under the terms of the lease, the Company is required to pay its proportionate share of real estate taxes, insurance and other charges.

In addition, the Company’s subsidiaries in New Jersey, China, and California lease their office and manufacturing facilities. FEI-Elcom leases 32,000 square feet of office and manufacturing space at current monthly rental of approximately $40,000 through the end of the lease which expires in March 2018. The lease for the FEI-Asia facility is for a one-year term with monthly rent of $1,000 through May 2018. FEI-Zyfer leases office and manufacturing space encompassing 27,850 square feet. Monthly rental payments are currently $31,200 for the remaining 4 months of the lease term. The Company has signed a second amendment to the lease, which extends the lease an additional 88 months, beginning October 1, 2017 and expiring January 31, 2025. The average annual rent over the period of the amendment is approximately $332,000.

Rent expense under operating leases for the years ended April 30, 2017 and 2016 was approximately $1.6 million and $1.5 million, respectively. The Company records rent expense on its New York building and FEI-Zyfer facility on the straight-line method over the lives of the respective leases. As a result, as of April 30, 2017 and 2016, the Company’s balance sheet includes deferred rent payable of approximately $99,000 and $214,000, respectively, which will be recognized over the respective rental periods.

Future noncancelable minimum lease payments required by the operating leases are as follows (in thousands):

Years ending
April 30,	Operating Leases
2018	$	1,535
2019		900
2020		322
2021		332
2022		342
Thereafter		994
Total future minimum lease payments	$	4,425