Best endeavours v reasonable endeavours
Many construction industry practitioners will have been confronted with a contract which requires the parties to use 'best' or 'reasonable' endeavours in performing obligations under the contract. This apparently minor difference however presents a real risk to a party if they are unaware of the difference in legal interpretation between the two terms.
Evidently an obligation to use 'best endeavours' implies a higher degree of commitment to perform a particular task when compared to 'reasonable endeavours' but, as is often the case, it is only when a contract dispute arises and Court proceedings follow that the reality of the difference becomes apparent.
There are no clear definitions of these terms upon which reliance can be made but case law has held that best endeavours means, amongst other things:
- To leave no stone unturned.
- To do what is reasonably to be expected in the circumstances.
- Not to do anything that will jeopardise the commercial interests of the obligor.
An immediate and obvious difficulty is that the word “reasonably” appears in a definition of 'best' endeavours. Furthermore, case law has also used similar language in defining reasonable endeavours.
Behind these definitions lies an expectation of what might be done to ensure that these obligations are met.
In the case of best endeavours it may be the case that a party has to commit extra resources or spend additional funds in order to meet the obligation, even to the extent that it is commercially damaging to the party concerned. Where the obligation is reasonable it is unlikely that this degree of obligation would be applied by the Courts.
And when it comes to testing these definitions in Court a subjective approach is adopted for best endeavours whilst it is an objective one for reasonable endeavours.
For the purposes of the layman, however, one can point to certain more simple facts:
- Reasonable endeavours will be less onerous than best endeavours.
- If a contract sets out specific steps to be taken as part of a reasonable obligation, ensure that these steps are indeed carried out. This is regardless of commercial considerations.
This article was created by: --Martinc 14:11, 22 November 2014 (UTC)
[edit] Related articles on Designing Buildings Wiki
- Delict.
- Duty of care.
- Duty to warn.
- Fitness for purpose.
- Good faith.
- Good faith – good grief.
- Reasonable skill and care.
- Unreasonable.
[edit] Relevant case law
Featured articles and news
What they are, how they work and why they are popular in many countries.
Plastic, recycling and its symbol
Student competition winning, M.C.Esher inspired Möbius strip design symbolising continuity within a finite entity.
Do you take the lead in a circular construction economy?
Help us develop and expand this wiki as a resource for academia and industry alike.
Warm Homes Plan Workforce Taskforce
Risks of undermining UK’s energy transition due to lack of electrotechnical industry representation, says ECA.
Cost Optimal Domestic Electrification CODE
Modelling retrofits only on costs that directly impact the consumer: upfront cost of equipment, energy costs and maintenance costs.
The Warm Homes Plan details released
What's new and what is not, with industry reactions.
Could AI and VR cause an increase the value of heritage?
The Orange book: 2026 Amendment 4 to BS 7671:2018
ECA welcomes IET and BSI content sign off.
How neural technologies could transform the design future
Enhancing legacy parametric engines, offering novel ways to explore solutions and generate geometry.
Key AI related terms to be aware of
With explanations from the UK government and other bodies.
From QS to further education teacher
Applying real world skills with the next generation.
A guide on how children can use LEGO to mirror real engineering processes.
Data infrastructure for next-generation materials science
Research Data Express to automate data processing and create AI-ready datasets for materials research.
Wired for the Future with ECA; powering skills and progress
ECA South Wales Business Day 2025, a day to remember.
AI for the conservation professional
A level of sophistication previously reserved for science fiction.
Biomass harvested in cycles of less than ten years.
An interview with the new CIAT President
Usman Yaqub BSc (Hons) PCIAT MFPWS.
Cost benefit model report of building safety regime in Wales
Proposed policy option costs for design and construction stage of the new building safety regime in Wales.
Do you receive our free biweekly newsletter?
If not you can sign up to receive it in your mailbox here.
























