Calculating Provision: Methods

The levels of WC provision required will be affected by several factors across our MSA’s; the calculations here are indicative only and WC provision should be considered on an individual MSA basis.

The average time a person takes to use the facilities should be taken as 1.5 minutes for women and 0.75 minutes for men. [2] Therefore, assuming an equal number of male and female users, there should be twice as many female units provided as male units.

2. BS6465-4:2010, 11.2.3.4.3 Time a person takes to use the facilities

Method 1 = Daily Peak Calcs

Method 2 = BS Calcs

Method 3 = Site Comparison Calcs

Method 1 = Daily Peak Calculations

By way of comparison Network Rail recommends that 1 unit (WC/urinal) be provided per 2500-3000 passengers of daily throughput.

A sensible equivalent for a Westmorland MSA would be…..

Therefore the recommended method for calculation provision is as follows:

AM 3 hr peak x 4 = Daily peak

Daily peak / 3000 = Total units required

Where the The ‘AM 3 hour peak’ is the total number of passenger entries/exits on a typical weekday between 07:00 - 09:59.

2. BS6465-4:2010, 11.2.3.4.3 Time a person takes to use the facilities

To calculate the provision required for female/male WC’s:
Total units required x 2/3 = Female Units
Total units required x 1/3 = Male Units

These calculations are only for the provision of separate-sex facilities; unisex facilities should be provided in addition to the calculated ‘total units required’ (see section ??).

Further guidance on calculating provision is available within BS6465-4:2010, and BS6465-1:2006.

[Insert patterns in WC usage info:

usage peaks - how many in a day? what times?

do patterns of usage depend on the location of the MSA i.e. greater proportion of leisure travellers seeing a gradual increase in WC usage throughout the week, with highest WC usage on Saturday. ]

PLACEHOLDER DAILY USAGE CHART SAMPLES - NEED WESTMORLAND DATA

Method 2 = BS Calcs

An alternative method for calculation WC provision can be found in BS6465-4:2010. This equation is used to determine provision in all public environments and is not specific to MSAs. The level of provision should always exceed the requirements as calculated using the method below.

N = (U x A x T) / P

N = Total units
U = Total potential users
A = Arrival rate, i.e. the percentage (as a decimal fraction) of the number of potential users (U ) likely to use the WC’s in a given period (P );
T is the time a person takes to use the facilities (in minutes);
P is the period of time used for measurement (in minutes).

The number of units required for male and female WC’s should be calculated separately as T (time a person takes to use the facility) is 0.75 minutes for men and 1.5 minutes for women. [3]

3. BS6465-4:2010, 11.2.3.4.3 Time a person takes to use the facilities

Extrapolating figures on WC usage over a one week period gives an approximate number of users for a year, and a corresponding average arrival rate (i.e. the percentage of the number of potential users likely to use the WC’s).

…….

PLACEHOLDER DAILY USAGE CHART SAMPLES - NEED WESTMORLAND DATA

Method 3 = Site Comparison Calcs

The turn in rate, footfall etc numbers for each site.

Cairn Lodge

Rheged

Tebay North

Tebay South

Junction 38

Gloucester North

Gloucester South

(Tatton)

Calculating Provision - Methods Method 1 = Daily Peak Calculations Method 2 = BS Calcs Method 3 = Site Comparison Calcs