Frequently asked questions

The NHBC System Review service offers a comprehensive review of innovative construction systems. From the UK’s leading new homes warranty and insurance provider, NHBC System Review is the route to acceptance for building systems used in homes covered by our Buildmark warranty product. NHBC System Review provides acknowledgement, in writing, that a construction system can meet the NHBC Standards. It also demonstrates that, subject to appropriate design and installation, the system can be used in homes covered by Buildmark. NHBC’s Innovation Team carries out a review of the system and, if deemed satisfactory, will provide a System Review certificate to the system owner and inclusion in the NHBC searchable database of Reviewed Systems.

NHBC Accepts will become NHBC System Review from 1 January 2026. This change follows a full review of the service and reflects its evolution into a comprehensive technical risk-management offering for systems that may be used on sites registered with NHBC.

NHBC System Review is for system owners – typically manufacturers of innovative building systems. Please note that system owners must possess the intellectual property rights to the system.

Systems reviewed under NHBC System Review must demonstrate that they meet NHBC Standards. The requirements are set out in the NHBC System Review Technical Document, available at www.nhbc.co.uk/SystemReview.

For most systems, the certificate will be valid for 24 months (subject to an annual fee). However, certificates for volumetric (modular) systems will be limited to 12 months duration. 

A bespoke fee is charged for each assessment to address the variety or form of innovative construction we review. After initial certification, an annual fee and a biennial periodic review are required. The bespoke fees charged reflect the complexity of the system and the number of factory and site inspections required, as well as the extent of any changes to the system.

The annual fee covers ongoing monitoring of the system throughout the 24-month certificate period, including face-to-face and Teams meetings and the cost of the required factory and site inspections.

We aim to respond to information received within three weeks. The system owner must then provide any further information we request and this timescale is outside our control. Assessment can take significantly longer if test evidence (including fire tests), third-party certification, or the system manual are not completed prior to engagement. Where information is missing or the certification process becomes unduly prolonged, we reserve the right to reforecast the associated costs.

Please refer to the Technical Document available at www.nhbc.co.uk/SystemReview.

The cost of Buildmark warranty must be paid for separately by registered NHBC developers for the purposes of providing Buildmark cover to a new home.

A review under NHBC System Review is not mandatory. There are many ways that a construction system can be shown to meet NHBC Standards. In general, most construction products are certified by a notified body or assessed by an independent technical approvals authority. See NHBC technical guidance 2.1/01 available at NHBC Standards - NHBC.

The benefit of the NHBC System Review service is that it provides confidence to a developer that the system has been thoroughly reviewed by NHBC in advance. This is particularly valuable for innovative systems that are not frequently seen on site. Without certification, the system can only be checked on an individual project basis with the risk that it does not meet NHBC Standards. NHBC System Review is an integral part of our overall technical risk management to deliver Buildmark warranty for innovative systems.

NHBC System Review is a review against NHBC Standards only. It is not intended for use for any purposes other than satisfying the requirements to achieve Buildmark warranty.

Please visit www.nhbc.co.uk/SystemReview to complete an enquiry form.

NHBC surveyors, inspectors and engineers will review and accept systems used on individual projects. However, NHBC System Review is the only way to demonstrate that a system has been thoroughly reviewed and is the only formal way that we will confirm acceptability to meet the NHBC Standards. Any historic letters from NHBC that provided written acceptance of a system are no longer valid, as this option has now been replaced by NHBC System Review.

Our System Review specialists usually visit the place of manufacture to understand how the system is assembled and the associated quality management process. Ongoing visits to the factory and to sites will be arranged where required.

Yes, but systems must meet NHBC technical requirements as set out in the NHBC Standards and TGN 2.1/01, covering independent technical assessment bodies. However, NHBC provides a bespoke review of innovative systems so that they can be assessed before getting onto site, giving confidence in their quality as well as assisting with assessment on site by the NHBC inspectors and project managers.

Buildmark warranty is provided on a completed home, including external works, substructure, superstructure and finishes and is for the benefit of the homeowner. The NHBC System Review service reviews the quality and conformity of the system elements that form part of the overall home.

This would potentially not meet NHBC Technical Requirements and could result in rejection of offer of cover under Buildmark warranty. Contact your NHBC project manager for details.

If a system is proven to be non-compliant in use, then NHBC may charge additional fees for any significant issues that affect your ability to deliver a compliant project.

The Technical Document describes in detail the primary evidence required prior to engagement with NHBC System Review. These include the full System Manual, system owners’ Quality Management/ISO 9001 certification, testing evidence including any required fire tests to recognised standards, and specific factory production controls for the manufacture of the system.

The NHBC System Review service can provide a pre-appraisal service, which can include consideration of the evidence available to support innovative prototypes and pre-construction concepts.

A bespoke technical risk management plan will be produced and project-specific technical conditions will be applied that are relevant to the details submitted. If there are features of the design that are not covered by the existing certification and that are not possible to risk manage by NHBC Operations, it is possible that offer of cover for Buildmark warranty may be denied. This may be withdrawn or denied depending on when the design is submitted.

Evidence to UK-recognised standards of performance is always required in order to assess a system. It will not be possible to progress an assessment if required fire tests are not available in their full and original form, not applicable to the makeup of the system or not provided by a body which is certified by UKAS. In some cases, an interpretative report by a suitably accredited and competent fire consultant may also be required. Assessments in lieu of testing (AILOTs) cannot be recognised on their own, in the absence of any comparable fire test data. Refer to Appendix B in Approved Document B Volume 1 for further details.

NHBC reserves the right to raise technical conditions related to the system that may require significant changes to the design or specification of the system. Please refer to earlier FAQs, which describe how a chargeable annual (or periodic) review will be carried out by the NHBC System Review team to ensure that conformity with recognised standards is maintained over time.

The NHBC System Review team will evaluate the extent of variation from the certified design and where the changes are significant, a periodic review will be carried out on a chargeable basis.

We would ask that the System owner notify us when a third-party certificate is received and our team will evaluate the scope of the certificate. If the full scope is covered by the third-party certificate, we would not offer a System Review in future but the live NHBC System Review certificate will continue until its duration expires. If there are gaps in the scope, we would consider re-engagement for a System Review in the future.