Meaning of depreciating assets
As explained in C3.301 the method of giving rollover relief varies depending on whether or not the replacement asset is a depreciating asset. In the case that it is a depreciating asset, the chargeable gain on disposal of the old assets is not deducted from the cost of the replacement assets as outlined in C3.307. The gain is instead held over and will be assessed on occurrence of the first of certain events.
For the purpose of these provisions an asset is a depreciating asset at any time at which it is either a wasting asset1 (see C2.221, C2.901) or will become a wasting asset within ten years of that time2. In effect, this means that a depreciating asset is one which has a predictable useful life not exceeding 60 years, which in fact applies to most of the business assets qualifying for relief.
As outlined in C3.303, for rollover relief purposes (although not for other chargeable gains purposes), land is treated as a separate asset from any buildings which are constructed on it. If a building is constructed on leasehold land, it is therefore the length of the trader's interest in the building which determines whether it is a depreciating asset for rollover relief purposes. However, the length of the trader's interest in the building cannot exceed the length of time left in the lease because on the expiry of the lease the land and building will revert