St Helens has a small but significant landslip site which has its own building requirements.
Landslip is closely governed by both the Building Act 2000 and Building Regulations 2004.
The relevant parts of both Acts are displayed below. Note that they are to be read in conjunction with each other.
BUILDING ACT 2000 - PART 10 - RESTRICTIONS ON BUILDINGS
Division 1 - Landslip areas
Effect of order in A landslip area
Section 150.
(1) A person must not erect, alter or add to a building in an A landslip area except in accordance with subsection (2).
(2) The Minister, on the recommendation of a General Manager may permit a person to -(a) erect in an A landslip area -
(i) a shed, or
(ii) a building that has a total floor area not exceeding 25 m2 and is not more than one story high; or(b) carry out building work, other than erections, in respect of a building in an A landslip.
Effect of order in B landslip area
Section 150.
(1) A person must not erect, alter or add to a building in a B landslip area except in accordance with the Building Regulations.
Penalty: Fine not exceeding 100 penalty units.
(2) A person must not store in a B landslip area -
(i) more than 10,000 litres of water; or
(ii) any explosive, flammable liquid or other dangerous substance
Penalty: Fine not exceeding 100 penalty units.
Activities prohibited in landslip areas
Section 152.
(1) A person who erects, alters or adds to a building in a landslip area must not aggravate any existing landslip conditions.
(a) excavate or deposit material: or
(b) use earthmoving or vibrating compaction equipment: or
(c) remove any vegetation.
Penalty: Fine not exceeding 100 penalty units.
BUILDING REGULATIONS 2004 - PART 2 - RESTRICTIONS ON BUILDINGS
Division 1 - Landslip Areas
Effect or order in B landslip areas
Regulation 9.
(1) For the purposes of section 151 of the Act, a person-
(a) may only erect, alter or add to a building in a B landslip area if the total floor area will not exceed 200 m2 when the building work is
completed; or
(b) may not erect, alter or add to a building in a B landslip area for the purpose of carrying out heavy industry in the building.
(2) A permit authority may grant a permit for the erection or alteration of, or addition to, a building in a B landslip area so that the building
has a floor area exceeding 200m? if -
(a) a certificate is given by a practicing professional engineer who has expertise in landslip areas: and
(b) a building surveyor grants a certificate of likely compliance.
(3) The certificate given by the practicing professional engineer under sub regulation (2) (a) must confirm that -
(a) the erection, alteration or addition can be carries out safely: and
(b) the building will be structurally sound; and
(c) the completed building will not affect the stability of the land
(4) For the purposes of sub regulation (2) (b), a building surveyor may grant a certificate of likely compliance to a person to erect or add to
a building in a landslip area if satisfied that
(a) the pipes installed are adequate to convey any stormwater, sullage, sewage, water storage overflow, sub-soil water and other waste
and water from the building work to -(1) a suitable drainage system; or
(2) an on-site waste water management system; or
(3) a natural water course; and(b) the stability of the landslip areas is not compromised.
Activities prohibited in landslip areas
Regulation 10.
(1) For the purposes of section 152(2) of the Act, a person may only -
(a) excavate, or deposit, material in a landslip areas if the excavation or deposition is carried out in such a manner as to allow rainwater
or seepage to drain from the site; or
(b) Permanently excavate or deposit any material for, or in connection with, building work in a landslip area if -(1) the excavation is not more than 600 millimetres in depth: and
(2) the material, when deposited, is not more than one metre in height above ground level and is compacted and graded so as not to aggravate existing landslip conditions: or(c) backfill a trench or hole in a landslip area if the trench or hole is backfilled with well compacted material which was previously removed from the trench or hole; or
(d) fell or remove trees or other vegetation for, or in connection with, building work on land in a landslip area if the person has obtained
the written agreement of a permit authority; or
(e) use any earth-moving or vibrating compaction equipment for, or in connection with, building work on land in a landslip area if the
person has obtained the written agreement of a permit authority.
(2) The building surveyor may grant a certificate of likely compliance for a permanent excavation of any vertical depth, or a deposit of filling
of any height, in a landslip area if satisfied on the basis of a certificate given by a practicing professional engineering geologist, or a
practicing professional engineer who has expertise in landslip areas, that the excavation or filling will not affect the stability of the land.
