Addendum
In a contract, the rights and obligations are created by the acts of agreement between the parties to the contract. English law does not require a particular form to contracts, and so the terms and ultimately the risk allocation are the choice of the parties involved.
Standard Form Contracts (SFC) aim to minimise the time and cost of creating contracts, but modifications may still be required. These provisions generally come in the form of amendments, but they can also come as an addendum. These two vehicles are similar, but they are structured differently and are used in different situations.
In its simplest form, an amendment is a change to an existing contract. In some cases, it may become necessary to amend a contract due to unforeseen circumstances. For instance, if certain clauses become obsolete or the industry changes and requires the inclusion of new terms, amendments may be required.
An addendum (or the plural, addenda) is written information that has been added to the original agreement. The information in an addendum is usually incorporated into the contract when the contract is executed.
Examples of addenda in construction contracts include:
- Acceleration agreements. It is common for acceleration agreements or costs to be treated as an addendum to the building contract. Sometimes acceleration agreements can be negotiated as an addendum to the contract in lieu of extensions of time caused by elements constituting client’s risk.
- BIM addendum. This addendum may provide for an information management structure, an information manager, a BIM execution plan and BIM protocols. There may also be a risk allocation and insurance provisions in relation to infringement of copyright and data loss.
[edit] Related articles on Designing Buildings
Featured articles and news
A now architectural practice looks back at its concept project for a sustainable oceanic settlement 25 years on.
Copyright and Artificial Intelligence
Government report and back track on copyright opt out for AI training but no clear preferred alternative as yet.
Embedding AI tools into architectural education
Beyond the render: LMU share how student led research is shaping the future of visualisation workflows.
Why document control still fails UK construction projects
A Chartered Quantity Surveyor explains what needs to change and how.
Inspiration for a new 2026 wave of Irish construction professionals.
New planning reforms and Warm Homes Bill
Take centre stage at UK Construction Week London.
A brief run down of changes intentions from April in an onwards.
Reslating an ancient water mill
A rare opportunity to record, study and repair early vernacular roofs.
CIOB Apprentice of the Year 2025/26
Construction apprentice from Lincoln Mia Owen wins this years title.
Insulation solutions with less waste for a circular economy
Rob Firman, Technical and Specification Manager, Polyfoam XPS explains.
Recycled waste plastic in construction
Hierarchy, prevention to disposal, plastic types and approaches.
UK Net Zero Carbon Buildings Standard V1 published
Free-to-access technical standard to enable robust proof of a decarbonising built environment.
Prostate Cancer Awareness Month
Why talking about prostate cancer matters in construction.
The Architectural Technology podcast: Where it's AT
Catch up for free, subscribe and share with your network.
The Association of Consultant Architects recap
A reintroduction and recap of ACA President; Patrick Inglis' Autumn update.
The Home Energy Model and its wrappers
From SAP to HEM, EPC for MEES and FHS assessment wrappers.
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.























