"[1] The concept of collateral warranty was sometimes regarded as "[...] the most unjust, oppressive, and indefensible in the whole range of common law.
Today a collateral warranty generally defines an agreement ancillary to another principal contract and/or a letter of appointment.
Collateral warranties may be provided by designers, building contractors and specialist sub-contractors.
The need for collateral warranties exists when the party that commissions a building will not carry the burden in the event of defects.
The collateral warranty establishes a contractual relationship between the housing association and the architect against defect.