- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 17 Jun 2013
Contra proferentem is a rule of construction applying to written documents or deeds. The rule provides that if the wording of an agreement is ambiguous or uncertain, but not otherwise, the contract should be construed more strongly against the person whose words they are rather than the other party.
In the case of John Lee & Son (Grantham) Ltd v Railway Executive (1949) it was found that:
'We are presented with two alternative readings of this document and the reading which one should adopt is to be determined, amongst other things, by a consideration of the fact that the defendants put forward the document. They have put forward a clause which is by no means free from obscurity and have contended... that it has a remarkably, if not extravagantly, wide scope and I think that the rule contra proferentem should be applied’
If a party has incorporated its own standard terms and conditions of trade into an agreement then in the event of ambiguity those terms and conditions will be construed contra proferentem that party. Where however the parties execute standard form contracts, the contra proferentem rule will only operate in respect of amendments or additions to the contract.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
The London Build Expo is hosting a Diversity in Construction panel and networking session on October 24.
Analysis can help develop a specification, but must not lead to inappropriate specifications being accepted.
Dos and don'ts for creating a smart home.
New ICE publication recommends pay-as-you-go tax to fund roads and other financing options.
BSRIA launches a White Paper on wearable technology and wellbeing in buildings.
Have the pressures of the market shredded the core values of professionalism?
Lead times are a measure of the amount of time that elapses between initiating and completing a construction process.
Government releases first tranche of funding for removal of unsafe high-rise cladding.
How to ensure UK transport infrastructure copes with severe winter weather.