Data source: Benchmarks are derived from service charge demands and historic billing records contained within the tracked dataset. User submissions are initially categorised as Unverified and then reviewed before being included in the benchmark calculations.
Core metric: The primary benchmark displayed is the annualised service charge (£/year). For comparability, the same figure is also expressed as £/month, and where floor area is available as £/sqft and £/sqm.
Normalisation of billing periods: Service charge demands are issued on varying billing cycles (e.g. half-yearly, quarterly, monthly, April–September, etc.). To ensure comparability, each invoice is normalised to a daily rate and then annualised as follows:
This approach avoids doubling half-year invoices, which can misstate the true annual cost.
Intensity metrics: Where floor area is available:
If area is in square feet, square metres are calculated using the following conversion (1 sqm = 10.7639 sqft).
Aggregation approach: Service charge datasets often include outliers (e.g. major works, adjustments to the reserve fund, balancing charges). Using the median provides a better representation of the typical charges within each sector.
Geography Used: The primary comparison is the postcode sector (e.g. E14 4). A London-wide benchmark, calculated from the full dataset, is displayed for context.
Forecasting: The five-year forecast is at 3% per annum, at time of publication. This projection is indicative and not predictive of any specific building’s future budget.