RIBA Professional Services Contracts: What Changed in 2024 and 2026?
RIBA has made a number of amendments to its Professional Services Contracts in recent years, reflecting changes to building safety legislation, the Building Regulations and the RIBA Plan of Work.
In 2024, amendments were introduced to bring the contracts into line with the Building Safety Act 2022, Part 2A of the Building Regulations and the revised RIBA Plan of Work. In 2026, RIBA has introduced a further set of amendments, this time focused specifically on its Domestic Professional Services Contract family.
So, what has actually changed, why does it matter, and what should architects and consultants be checking if they are still working from an older version of the contracts?
A reminder of the current RIBA contract suite
Before looking at the amendments, it is worth briefly revisiting the current RIBA contract suite.
The RIBA Building Contracts cover the agreement between the client and contractor. These include the RIBA Domestic Building Contract, aimed at consumer clients, and the RIBA Concise Building Contract, intended for commercial clients.
The RIBA Professional Services Contracts cover the appointment of architects and consultants and are divided broadly into consumer and commercial contracts.
For domestic clients, the suite includes:
The RIBA Domestic Professional Services Contract for architectural services.
The RIBA Domestic Professional Services Contract for Conservation Architectural Services.
The RIBA/BIID Domestic Professional Services Contract for Interior Design Services, published jointly with the British Institute of Interior Design.
For commercial clients, the suite includes:
The Standard Professional Services Contract.
The Concise Professional Services Contract.
The Sub-consultant Professional Services Contract.
The Client Adviser Professional Services Contract.
There are also separate appointments for the Building Regulations Principal Designer and CDM Regulations Principal Designer roles. These allow those responsibilities to be formally appointed rather than automatically bundling them into the main architectural services agreement.
How the Professional Services Contract is structured
The Professional Services Contract is broadly divided into four parts:
The Agreement.
The Contract Details.
The Contract Conditions.
The Schedule of Services.
There is also a Contract Checklist at the front, which acts as an aide-memoire but does not itself form part of the contract.
The Contract Details run from Item A through to Item M and cover matters including:
The client's details.
The architect or consultant's details.
The site address.
The Project Brief, Construction Cost and Project Programme.
Other Client Appointments.
The Basic Fee.
Time charges and expenses.
Payment frequency.
Professional indemnity insurance.
Dispute resolution.
Information formats.
Any Supplementary Agreements.
The Contract Conditions contain the definitions and operative clauses, covering areas such as:
General Interpretation.
Client's Responsibilities.
Architect or Consultant's Responsibilities.
Assignment and Subcontracting.
Fees and Expenses.
Copyright and Licence.
Liability.
Professional Indemnity Insurance.
The Client's Right to Cancel.
Suspension or Termination.
Dispute Resolution.
Information Formats.
The Schedule of Services is now divided into four sections, with individual services selected as applicable:
Architect or Consultant Services, mapped against RIBA Plan of Work Stages 0–6.
Additional Architect or Consultant Services.
Building Regulations Principal Designer Services.
CDM Regulations Principal Designer Services.
The 2024 amendments: building safety and Principal Designer roles
The 2024 amendments were primarily about bringing the contracts into line with the Building Safety Act 2022, Part 2A of the Building Regulations and the revised RIBA Plan of Work.
A significant change was the introduction of clearer contractual provisions around the Building Regulations Principal Designer and CDM Regulations Principal Designer roles. The Architect or Consultant can now be appointed to undertake either or both roles, with the relevant services selected within the Schedule of Services and the applicable project stages identified.
Competence assessments
If an Architect or Consultant is taking on the Building Regulations Principal Designer role, the contract requires them to assess their competence before entering into the appointment.
Clause 3.2.8 requires consideration of competence under Regulation 11F of the Building Regulations and, where the individual is also acting as Building Regulations Principal Designer, competence under Regulation 11G.
The position does not simply end at the point of appointment. If the Architect or Consultant's competence changes, or there is a material change to the Project Brief that could affect the original assessment, the Client must be informed in accordance with the relevant regulatory requirements.
For anyone taking on the Building Regulations Principal Designer role, documenting that competence assessment before signing the contract is therefore an important practical step.
What happens if no Principal Designer is appointed?
The amended contract also reflects the regulatory default positions.
If the Client does not appoint a Building Regulations Principal Designer, the designer in control of the design phase is deemed to be the Building Regulations Principal Designer.
Similarly, if a CDM Regulations Principal Designer is not appointed, the designer in control of the pre-construction phase is deemed to hold that role.
In other words, leaving the relevant appointment box blank does not necessarily mean that the responsibility disappears. The statutory duties can still attach to the person or organisation actually controlling the relevant phase of the work.
The 2026 amendments: a closer focus on domestic contracts
The latest amendments have a narrower focus.
The 2026 amendments apply specifically to the Domestic Professional Services Contract family. The other Professional Services Contracts remain at the 2024-amended position.
The current domestic architectural contract is therefore the:
RIBA Domestic Professional Services Contract 2020 – 2024 and 2026 amendments.
The same 2026 updates also apply to the domestic conservation architectural contract and the RIBA/BIID domestic interior design contract.
The changes are particularly relevant to projects where an individual homeowner is appointing an architect or consultant for work to their own home.
When is the Domestic Professional Services Contract appropriate?
The Domestic Professional Services Contract is intended for domestic commissions of any value where:
The Client is appointing the Architect or Consultant in their own name.
The project concerns the Client's own home.
The works are being procured using a standard form of building contract, such as the RIBA Domestic Building Contract.
Tendering takes place at the end of Stage 4, Technical Design, using the traditional procurement approach.
It can therefore be used for projects such as renovations, extensions, maintenance works and new homes. The Client must fall within the relevant statutory definition of either a domestic client under the Building Regulations and CDM Regulations or a consumer under the Consumer Rights Act 2015.
The contract is not intended for business clients or for projects where the property is being used as part of a business. That includes projects for organisations such as charities, religious organisations and not-for-profit bodies. It is also not intended for properties that are being let, including circumstances where a second home is being operated as a holiday rental or let to tenants.
Higher-risk buildings under the Higher-Risk Buildings Regulations 2023 are also outside the scope of the domestic contract, with the Standard Professional Services Contract being more appropriate in those circumstances.
These distinctions are important because selecting the wrong contract at the outset can create problems later, particularly where the client's status or intended use of the property changes.
What changed in 2026?
The 2026 amendments introduce several changes that practices should be aware of.
1. Greater clarity around the net contribution clause
Clause 7.3 deals with the net contribution position.
Broadly, this means that where several parties may be responsible for a loss, the Architect or Consultant's liability is intended to reflect their proportionate responsibility rather than exposing them to the whole loss simply because other responsible parties cannot meet their share.
The 2026 amendment provides clearer guidance around this provision and places greater emphasis on the Client having appropriate contractual arrangements with their other consultants and contractors.
This has an important practical implication.
At the beginning of a project, it is sensible to encourage the Client to ensure that other professional appointments and contractor contracts contain appropriately aligned provisions.
Otherwise, the Architect or Consultant may have the benefit of a net contribution provision while the Client still finds themselves unable to recover the remaining proportion of a loss from another party.
2. Tighter controls around additional fees
Clause 5.5 identifies circumstances in which the Architect or Consultant can charge additional fees on a time basis.
These can include circumstances such as:
Work that is not included within the Construction Cost.
A request to vary a service that has already been completed.
Circumstances where substantial elements of the design cannot reasonably be finalised before construction starts.
Delays or disruption to performance that are not the Architect or Consultant's fault.
The 2026 amendments reinforce the principle that additional fees should be connected to these defined circumstances and matters outside the Architect or Consultant's reasonable control.
Clause 5.6 remains particularly important because it requires the Architect or Consultant to notify the Client as soon as they become aware that the circumstances in clause 5.5 apply. The practical lesson is straightforward: document the issue when it arises.
Do not wait until the next invoice to raise an additional fee. If circumstances arise that may trigger an entitlement to additional fees, notify the Client promptly and in writing.
3. The late payment interest rate has changed
One of the more straightforward amendments concerns late payment interest.
The rate under clause 5.22 has been reduced from 8% to 5% per year over the Bank of England dealing rate. That means practices working from older versions of the contract should check their wording carefully.
If you are dealing with an overdue payment under the current contract, the relevant contractual figure is 5%, rather than the 8% figure that appears in earlier versions.
4. Greater clarity around disputed payments
The amendments also provide clearer wording around the Client's ability to withhold disputed payments.
Clauses 5.16 to 5.20 contain the existing Notice of Intention to Pay Less provisions. Where a Client intends to pay less than the Notified Sum, they must provide written notice at least five days before the Final Date for Payment. The notice needs to state the amount the Client considers due, explain the basis of the calculation and identify the grounds for withholding payment.
The updated wording makes the Client's position clearer and more prominent. This also highlights the importance of the Architect or Consultant getting their own payment administration right.
Under clause 5.12, Payment Notices should be clear and properly reasoned. A well-prepared account and Payment Notice can reduce uncertainty and narrow the scope for a payment dispute.
5. Defective Premises Act and limitation periods
Another important amendment concerns liability and the Defective Premises Act 1972, as amended.
The contract now makes clearer how its limitation provisions interact with statutory rights.
Generally, clause 7.1 provides limitation periods of:
Six years for an action founded on a simple contract.
Twelve years where the contract is executed as a deed.
These periods run from the relevant date specified in the contract, generally linked to Practical Completion or completion of the last Services, whichever is earlier.
However, this is subject to statutory rights, including claims under the Defective Premises Act, where the applicable limitation period can extend to 15 years from completion of the dwelling.
Clause 7.4 also makes clear that the liability provisions do not exclude or limit liabilities that cannot lawfully be excluded or limited, such as liability for death or personal injury caused by negligence or for fraud.
The amendment does not change the underlying legislation. Instead, it brings the contractual wording into closer alignment with the legal position.
That is important because a contractual liability cap should not give either party the impression that a statutory liability can simply be contracted out of when the law does not permit that.
6. Photography rights must be agreed in advance
The 2026 amendments also address project photography.
Previously, clause 3.3 allowed the Architect or Consultant, subject to the Client's reasonable agreement, to publish photographs and other information relating to the project, with the Client providing reasonable access for that purpose.
The updated approach places greater emphasis on agreeing photography rights with the Client in advance.
For architectural practices, this is worth addressing early in the appointment rather than assuming that permission can be obtained after completion.
With project photography playing such an important role in practice marketing, it is much better to have a clear agreement about what can be photographed, when photographs can be taken, how they can be used and whether there are any confidentiality or privacy concerns.
7. The 14-day cancellation right is more prominent
The final major change concerns the consumer's 14-day cancellation right.
Under clause 9, the Client can cancel the contract for any reason by giving written notice, including by email, within 14 days of signing the Agreement.
There are provisions dealing with work that has been instructed before the contract was made or before the cancellation period has expired. Where such instructions have been confirmed in writing, the Architect or Consultant can be entitled to fees and expenses properly due for work carried out before the cancellation notice is received.
The contract also includes a template Notice of Cancellation in the Appendix.
The 2026 amendment makes the cancellation right more prominent within the contract, helping to ensure that a consumer client is less likely to overlook this statutory protection.
The 2026 amendments apply across the Domestic family
It is important not to assume that these amendments only apply to the standard domestic architectural contract.
The same 2026 changes apply across the three Domestic Professional Services Contracts:
RIBA Domestic Professional Services Contract 2020 for architectural services.
RIBA Domestic Professional Services Contract 2020 for Conservation Architectural Services.
RIBA/BIID Domestic Professional Services Contract for Interior Design Services.
They do not, however, extend across the wider commercial Professional Services Contract suite.
What should practices do now?
If your practice still has older RIBA contracts sitting in templates, on your server orwithin project folders, now is a good time to check which edition you are actually using.
In particular, check:
Which RIBA contract you are using. Make sure the client's status and the nature and intended use of the project are appropriate for the domestic or commercial contract selected.
Whether you are using the latest amended edition. For domestic projects, check that you are using the 2020 contract incorporating both the 2024 and 2026 amendments.
Principal Designer appointments. If you are taking on the Building Regulations Principal Designer or CDM Regulations Principal Designer role, make sure the relevant services have been selected and that the necessary competence assessment has been undertaken.
Other Client Appointments. Consider whether the Client's other professional appointments and contractorcontracts contain appropriate and compatible liability provisions, particularly where a net contribution clause is involved.
Additional fees. If circumstances arise that could trigger additional fees, notify the Client promptly and keep a written record.
Payment notices. Make sure your Payment Notices and any responses to payment disputes are issued correctly and within the contractual timescales.
Photography. Agree photography and publication rights with the Client at the outset rather than leaving the issue until the project is complete.
Cancellation rights. Make sure consumer clients are aware of their 14-day cancellation rights and that any instruction to begin work during that period is properly documented.
Liability and limitation. Be aware that contractual limitation provisions operate alongside statutory rights, including those arising under the Defective Premises Act.
The key takeaway
The latest RIBA amendments are not simply cosmetic changes to the wording of the contracts.
The 2024 amendments were principally about bringing the Professional Services Contracts into line with the changing building safety and regulatory environment, particularly the Building Safety Act, within the Domestic Professional Services Contract family. They provide greater clarity around net contribution, additional fees, payment disputes, liability and statutory limitation periods, Part 2A of the Building Regulations and the introduction of the Building Regulations Principal Designer role.
The 2026 amendments take a more consumer-focused approach within the Domestic Professional Services Contract family. They provide greater clarity around net contribution, additional fees, payment disputes, liability and statutory limitation periods, while also addressing photography rights and the consumer's cancellation rights.
For practices, the practical message is simple: don't treat the contract as a static document.
The contract you have been using for years may no longer be the current version, and relatively small changes in wording can have significant implications for how you administer fees, payments, liability, client communications and statutory responsibilities.
For domestic projects in particular, check that you are using the RIBA Domestic Professional Services Contract 2020 incorporating the 2024 and 2026 amendments, and make sure your practice procedures reflect the changes rather than simply relying on the updated wording sitting in the contract.
Ultimately, the purpose of these amendments is to keep the contract aligned with current regulation and professional practice, while making the contractual relationship clearer for both the architect or consultant and the consumer client.
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