Property and Equipment, Net

Furniture and fixtures, computer software and equipment, leasehold improvements and real property are recorded at cost and presented net of depreciation. We record land at historical cost. During the application development phase, we record capitalized development costs in our construction in progress account and then reclass the asset to internal-use software when the project is ready for its intended use, which is usually when the code goes into production. Furniture and fixtures and computer software and equipment are depreciated on a straight-line basis over lives ranging from three to five years. Internal-use software is amortized on a straight-line basis over a three-year period. Leasehold improvements are amortized on a straight-line basis over the shorter of the lease terms or the asset lives. Real property is amortized on a straight-line basis over 15 years.

The components of property and equipment, net are as follows (in thousands):



	December 31,
	2018			2017
Furniture and fixtures	$	4,102		$	3,699
Computer software and equipment	16,228			11,624
Internal-use software	5,072			1,643
Construction in progress	3,790			4,605
Leasehold improvements	18,338			15,849
Real property	707			502
Land	508			398
Total property and equipment	48,745			38,320
Accumulated depreciation	(20,988		)	(14,861		)
Property and equipment, net	$	27,757		$	23,459

Depreciation expense related to property and equipment for the years ended December 31, 2018, 2017 and 2016 was $5.7 million, $5.4 million and $4.7 million, respectively. Amortization expense related to internal-use software of $0.8 million, $0.4 million and $0.4 million was included in those expenses for the years ended December 31, 2018, 2017 and 2016, respectively. Within the Alarm.com segment, we disposed of and wrote off $1.4 million and $0.8 million of capitalized costs to research and development expenses within the consolidated statements of operations primarily related to the design of internal-use software that no longer met the requirements for capitalization during the years ended December 31, 2018 and 2017. There were no disposals and write-offs of property and equipment that impacted the consolidated statements of operations during the year ended December 31, 2016.