Storey Enclosure Method

Storey enclosure unit – It measure the area of external walls, floors and roof areas (effectively enclosing the building) and multiplying them by an appropriate weighting factor.

Not much used in practice and involves greater calculation.

Historical data are not readily available

Provides a single rate

Take into account of difference in plan shape total floor area, vertical position of the floors, overall height, storey height, extra costs of providing usable floor areas below ground.

1.  Floor areas, measured from the internal face of external walls and subject to the following  weightings

basements X 3

ground floor X 2

first floor X 2,15

second floor X 2.30 and add 0,15 for each successive floor

2. Roof areas are measured in its plan projection, to the extremities of eaves: roof x 1. 

3. External wall areas, measured on the external face of the walls:

 basement wall area      X 2    (basement floor to ground floor  level)

Above ground wall areas X 1  (ground floor to ceiling of top floor with no deduction for openings)

When this method was suggested, it aimed at  overcoming the problems detected in other single-rate estimating methods, by taking into account variations in plan shape and storey height. Unfortunately, the method was never totally adopted by construction professionals because it requires much more calculations than other single-rate methods and because the rates needed cannot be directly extracted from historical data

 Storey enclosure unit Method Estimate