Ameresco, Inc. Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2015

Changes in the allowance for doubtful accounts are as follows:



	Three Months Ended March 31,
	2015			2014
Allowance for doubtful accounts, beginning of period	$	2,851		$	1,519
Charges to costs and expenses	33			244
Account write-offs and other	(91		)	(136		)
Allowance for doubtful accounts, end of period	$	2,793		$	1,627

Depreciation and amortization of property and equipment are computed on a straight-line basis over the following estimated useful lives:



Asset Classification		Estimated Useful Life
Furniture and office equipment		Five years
Computer equipment and software costs		Three to five years
Leasehold improvements		Lesser of term of lease or five years
Automobiles		Five years
Land		Unlimited