Reliance letters in design and construction
Reports are often commissioned by parties involved in the design and construction of built assets that another party (other than the original client) then has to rely on to support or inform their own activities. Under such circumstances, the author of the report might issue a reliance letter, confirming that the third party can rely on the contents of the report, or can rely on a specific part of the report.
For example, an organisation selling a site might commission an assessment of geotechnical or environmental conditions that a purchaser later relies on when deciding whether to buy the site and at what price. Under these circumstances, the author of the report might issue a letter confirming that the purchaser can rely on the contents of the report.
Such a letter might include:
- A description of the report(s) to which the letter relates.
- The reason for the reliance.
- A warrant that the author exercised reasonable skill and care in preparing the report.
- Details of the original appointment agreement, perhaps limiting liability to that under the appointment (this requires that a copy of the appointment is provided).
- Other limitations to liability, such as a limiting period.
- A licence for use of the report.
- Confirmation of professional indemnity insurance.
- Consideration from the beneficiary to the consultant.
- A right to assign the benefit of the letter (for example to funders).
- Execution, perhaps as a deed.
This can be seen as a quicker and easier arrangement than providing a collateral warranty, or relying on the provisions of the Contracts (Rights of Third Parties) Act. However, it is important to ensure that the letter is carefully drafted and that the correct details are entered. Whether the result of a reliance letter is simply a common law duty to use reasonable skill and care, or whether it amounts to a contract between the parties that may introduce a greater duty will depend on the wording of the letter.
There are four essentials of a contract:
- Two or more parties; and
- An intention to create legal relations; and
- An agreement; and
- Consideration
The two essentials that might be disputed are an intention to create legal relations and consideration. This might be demonstrated by a consideration clause and by both parties executing the letter. However, even in the absence of such provisions, it may be apparent from the actions of the parties that the recipient of the letter has relied on it to their detriment, and this may be sufficient to establish ‘consideration’.
[edit] Related articles on Designing Buildings Wiki
- Assignment.
- Collateral warranty.
- Third party rights.
- Letter of intent.
- Letter of appointment.
- Essentials of a contract
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
The heritage of nuclear and conventional power stations.
New measures to stop people being ripped off
Government to protect families from cowboy builders and aggressive bailiffs.
New Futurebuild showcase brings an innovation-first approach.
National Planning Policy Framework
Understanding the 2026 changes.
ECA's public affairs priorities
Member consultation opens to shape priorities for 2027 to 2030.
Dutyholder responsibilities from 1 July 2026.
Where performance meets practice
The Building Envelope Stage at UKCW Birmingham.
CIAT publishes briefing on planning reforms.
Leaders in Learning for Practice Network
Call for conservation leaders in learning to register interest in new network.
The importance of early engagement
Construction lessons from the Trillium HealthWorks Experience Centre.
Mayors are to be given planning call in powers
Mayors across England will be able to make the most important planning decisions.
The Master Builder: William Butterfield and his times. Book review.


















Comments