Judge: Irwin LJ and Coulson LJ
Citation:  EWCA Civ 1220
The court provided guidance as to the approach to detailed assessment. The bill should be assessed line by line, dealing with reasonableness and proportionality simultaneously if possible. The proportionality of the total figure must also be considered. If that figure is disproportionate, a further assessment is required (See also the summaries regarding the recoverability of the ATE premium, and the assessment of proportionality).
“ First the Judge should go through the bill line by line assessing the reasonableness of each item of cost. If the Judge considers it possible, appropriate and convenient when undertaking that exercise, he or she may also address the proportionality of any particular item at the same time. That is because, although reasonableness and proportionality are conceptually distinct, there can be an overlap between them, not least because reasonableness may be a necessary condition of proportionality: see Rogers at paragraph 104. This will be a matter for the Judge. It will apply, for example, when the Judge considers an item to be clearly disproportionate, irrespective of the final figures.
 At the conclusion of the line by line exercise, there will be a total figure which the Judge considers to be reasonable (and which may, as indicated, also take into account at least some aspects of proportionality). That total will have involved an assessment of every item of cost, including fees, the ATE premium and the like.
 The proportionality of that total figure must be assessed by reference to both Rule 44.3(5) and 44.4(1). If that total figure is found to be proportionate, then no further assessment is required. If the Judge regards the overall figure as disproportionate, then a further assessment is required. That should not be line by line, but should instead consider various categories of cost, such as disclosure or expert’s reports, or specific periods where particular costs were incurred, or particular parts of the profit costs.
 At that stage, however, any reductions for proportionality should exclude those elements of costs which are properly regarded as unavoidable, such as Court fees, the reasonable element of the ATE premium in clinical negligence cases, and the like. Specifically, therefore, if the ATE premium is assessed as reasonable, it will not fall to be reduced by any further assessment of proportionality.
 The Judge will undertake the proportionality assessment by looking at the different categories of cost (excluding the unavoidable items noted above) and considering in respect of each such category, whether the costs incurred were disproportionate. If yes, then the Judge will make such reduction as is appropriate. In that way, reductions for proportionality will be clear and transparent for both sides.
 Once any further reductions have been made the resulting figure will be the final amount of the costs assessment. There will be no further stage of standing back and, if necessary, undertaking a yet further review by reference to proportionality. That would introduce the risk of double counting.”