17 property, plant and equipment


		Owned assets												Right-of-use lease assets (Note 19)
				Buildings and
		Network		leasehold						Assets under				Network		Real
(millions)	Note	assets		improvements		Other		Land		construction		Total		assets		estate		Other		Total		Total
AT COST
As at January 1, 2018		$	28,724	$	3,077	$	1,095	$	48	$	655	$	33,599
Additions 1			1,039		27		37		—		1,265		2,368
Additions arising from business acquisitions			4		13		9		—		—		26
Dispositions, retirements and other			(767)		56		(52)		—		—		(763)
Assets under construction put into service			956		100		85		—		(1,141)		—
As at December 31, 2018		$	29,956	$	3,273	$	1,174	$	48	$	779	$	35,230
As at January 1, 2019
As previously reported		$	29,956	$	3,273	$	1,174	$	48	$	779	$	35,230	$	—	$	—	$	—	$	—	$	35,230
IFRS 16, Leases transitional amount	2(c)		—		—		—		—		—				—		1,011		30		1,041		1,041
Reclassification arising from implementation of IFRS 16			(101)		—		(1)		—		—		(102)		101		—		1		102		—
As adjusted			29,855		3,273		1,173		48		779		35,128		101		1,011		31		1,143		36,271
Additions 1			1,073		42		84		—		1,217		2,416		219		274		16		509		2,925
Additions arising from business acquisitions	18(b)		127		3		12		—		—		142		—		12		11		23		165
Dispositions, retirements and other			(644)		(125)		(48)		—		—		(817)		(101)		(18)		2		(117)		(934)
Assets under construction put into service			1,302		121		152		—		(1,575)		—		—		—		—		—		—
Net foreign exchange differences			—		—		—		—		—		—		—		(12)		—		(12)		(12)
As at December 31, 2019		$	31,713	$	3,314	$	1,373	$	48	$	421	$	36,869	$	219	$	1,267	$	60	$	1,546	$	38,415
ACCUMULATED DEPRECIATION
As at January 1, 2018		$	19,638	$	1,884	$	709	$	—	$	—	$	22,231
Depreciation			1,431		115		123		—				1,669
Dispositions, retirements and other			(769)		51		(43)		—		—		(761)
As at December 31, 2018		$	20,300	$	2,050	$	789	$	—	$	—	$	23,139
As at January 1, 2019
As previously reported		$	20,300	$	2,050	$	789	$	—	$	—	$	23,139	$	—	$	—	$	—	$	—	$	23,139
Reclassification arising from implementation of IFRS 16			(1)		—		—		—		—		(1)		1		—		—		1		—
As adjusted			20,299		2,050		789		—		—		23,138		1		—		—		1		23,139
Depreciation 2			1,473		120		135		—		—		1,728		13		177		11		201		1,929
Dispositions, retirements and other			(712)		(118)		(49)		—		—		(879)		(8)		(3)		5		(6)		(885)
As at December 31, 2019		$	21,060	$	2,052	$	875	$	—	$	—	$	23,987	$	6	$	174	$	16	$	196	$	24,183
NET BOOK VALUE
As at December 31, 2018		$	9,656	$	1,223	$	385	$	48	$	779	$	12,091	$	—	$	—	$	—	$	—	$	12,091
As at December 31, 2019		$	10,653	$	1,262	$	498	$	48	$	421	$	12,882	$	213	$	1,093	$	44	$	1,350	$	14,232

(1)

For the year ended December 31, 2019, additions include $153 (2018 – $(15)) in respect of asset retirement obligations (see Note 25).

(2)

For the year ended December 31, 2019, depreciation includes $5 in respect of impairment of real estate right-of-use lease assets.

As at December 31, 2019, our contractual commitments for the acquisition of property, plant and equipment totalled $136 million over a period ending December 31, 2022 (2018 – $148 million over a period ending December 31, 2022).