Stratum statements

All lots in a strata plan are a cubic space and must be limited in height and depth. Stratum statements are required if a lot is not limited in height and or depth by a structure. Lots which are within a building are generally accepted to extend from the upper surface of the floor to the lower surface of the ceiling. If this is the case no stratum statement is required.

When is a statement required?

A stratum statement will be required for all lots outside a building which are not fully covered by a structure or do not have a structural base for their entire area. These areas of the plan should be uniquely identified and stratum statements provided for each unique area. Part lots which are outside a building generally fall into four categories with their requirements for stratum statements as follows:

  • A statement is required for the height and depth.
  • A statement is required for height only because a structural base exists for its entire area.
  • A statement is required for the depth only because a structural cover exists for its entire area.
  • No statement is required if the area has a structural base and cover for its entire area.

Maximum limit

The maximum limit for the height or depth limit of a lot defined by a stratum statement acceptable to LPI is 50 metres. If there is a requirement to exceed this limit an application should be put to the Plan and Title Advisor at plan-info@lpi.nsw.gov.au for approval.

Composition of the stratum statement

All stratum statements are comprised of 3 parts.

  • The unique description of the part of lot it relates to e.g. Courtyard, Balcony, Terrace etc.
  • The datum which the boundary is related to. The datum must be a stated structural surface within the parcel.
  • The boundary's relationship to the datum. This is a distance in metres above or below the datum.

It is possible to describe both the upper and lower limits of a lot in a single statement. If the stratum limits are complex it is recommended that separate statements be provided so the lot is clearly defined.

The unique description

Each part of a lot which requires a stratum statement must have a unique description. If there are several parts with the same stratum limits they may be given the same description.

Generally they are described as architectural feature, such as balcony, courtyard, terrace etc. However they may also be designated with an alpha character.

It is generally accepted by LPI that some descriptions would indicate that the area has a structural base and will not require a stratum statement for their lower limit.

The datum

The datum must be a permanent structural surface within the parcel. The most commonly used datum is the upper surface of a floor. Most structures used for a datum will have an upper and lower surface. It will be necessary to indicate a specific surface. Although when a surveyor is on site there may be no doubt regarding which surface is to be used as the datum, the examiner in LPI must be certain the boundaries have been defined without ambiguity.

When selecting the datum the surveyor should ensure that it is suitable. Some points which should be considered include:

  • Is the datum level?
  • Is there only one level to a floor? Sometimes the floor of a dwelling may have 2 or more.
  • Refer to the upper surface at the front door or another specific point if there is more than one level.
  • Is the datum likely to be altered in any way? Tiles may be added to balcony floor which may cause doubt as to the position of a stratum limit. Refer to the material of the floor, e.g. Concrete, Tiles, Timber etc.
  • In many cases a garage will have the most substantial floor. This would be an excellent datum as also it is unlikely it will be covered by carpet or other flooring at a later date.
  • Are there any structures within the stratum limits? Eaves and gutters may partly cover a balcony. If this is the case a rider may be added to the statement.

Balconies are limited in height to 3 metres above the upper surface of their concrete floor except where covered within this limit.

Commonly used terms

The following are some commonly used terms to describe areas outside of the building:

Courtyard, Garden Area, Yardspace

It would not be expected that these areas have a structural base or are fully covered and statements would be required.

Balcony, Patio, Porch, Veranda, Terrace, Deck, Car Space

It would be expected that these areas have a structural base but are not necessarily fully covered

Carport

It would be expected that this area would be fully covered by a structure but not necessarily have a structural base.

The above descriptions are examples and suggestions only. The surveyor should select an appropriate description for parts of the lot which require statements. A description may be as simple as designating the area with an English alpha character.

Describing the datum

In most case a structure such as a floor of ceiling will have two surfaces. The statement must be related to either the upper surface or lower surface. Examples:

  • the upper surface of the ground floor of the respective dwelling
  • the upper surface of the garage floor of the respective lot
  • the lower surface of the eaves which partly covers them

The relationship of the boundary should be a distance in metres above or below the datum.

  • The courtyards are limited from (X) below to (Y) above the upper surface of the ground floor of the residence.
  • The balcony is limited in height to the horizontal projection of the underside of the eaves which partly cover it.

Acceptable datum

The datum used for the stratum statement must be a permanent structure within the parcel. The structure should be horizontal unless a specific point is indicated. Most permanent floors or ceilings are acceptable as a datum. It should be noted that pavers and similar items are not acceptable unless they are fixed to a structural base.

In some circumstances there may be a structure which partly covers an area with a stratum statement such as the eaves of a building. In other cases there may be a structure beneath the ground but within the stratum limits. These structures must be considered when composing the stratum statement. A common phrase added to a stratum statement is except where covered. Examples:

  • Courtyards are limited from 5 below to 10 above the upper surface of the ground floor of the adjoining dwelling except where covered.
  • Balconies are limited to 3.5 above the upper surface of their concrete floor except where covered.
  • Terrace is limited to 3 above the upper surface of the floor of the respective garage except where covered.
  • Courtyard are limited in depth to 3 below the upper surface of the floor of the adjoining unit except where there is a concrete base and in height to 8 above the upper surface of the floor of the adjoining unit except where covered.

Example stratum statements

The following is a list of examples of stratum statements. They are not intended to be copied to floor plans as written. Their intention is to provide a guide as to the format of a statement and provide some examples of various descriptions. The surveyor preparing the plan should consider carefully the content of all stratum statements for each plan specifically.

(a) Courtyards are limited from 5 below to 10 above the upper surface of the ground floor of the adjoining dwelling except where covered.

(b) Courtyards are limited in height to 8 metres above the upper surface of the ground floor of the adjoining dwelling except where covered within this limit.

(c) Courtyards are limited in depth to 3 below the upper surface of the ground floor of the adjoining dwelling except where the basement roof exists below.

(d) Courtyard are limited in depth to 3 below the upper surface of the floor of the adjoining unit except where there is a concrete base and in height to 8 above the upper surface of the floor of the adjoining unit except where covered.

(e) Balconies are limited to 3.5 above the upper surface of their concrete floor except where covered within this limit.

(f) Balconies are limited in height to the horizontal projection of the underside of the eaves which partly cover them.

(g) The Terrace is limited to 3 above the upper surface of the floor of the respective garage except where covered.