NHBC Standards 2011

1.1 Introduction to the Standards and Technical Requirements

Application of the Standards
Composition of the Standards
Technical Requirements
Performance Standards
Limitations on use
Standards and Codes of Practice
Technical Requirements
  R1 - Statutory requirements
  R2 - Design requirement
  R3 - Materials requirement
  R4 - Workmanship requirement
  R5 - Structural design requirement


This Chapter introduces the Standards and gives the Technical Requirements.

NHBC Standards do not cover aspects of health and safety relating to building operations and to the handling and use of certain building materials. Such matters are covered by statutory requirements.



The NHBC Standards give the Technical Requirements, Performance Standards and Guidance for the design and construction of dwellings acceptable to NHBC. In the Standards, a DWELLING means a HOME as defined in the NHBC Rules.

The Standards come into effect for every NHBC registered home whose foundations are concreted on or after the 1 January 2011 and apply throughout the UK, unless otherwise stated.


The Standards are divided into 10 Parts, each covering a particular aspect. All parts may not currently contain chapters. The Parts follow the usual construction process; from design through to construction on site. NHBC Standards do not cover aspects of health and safety relating to building operations and to the handling and use of certain building materials. Such matters are covered by the statutory requirements.

In general, each Chapter is made up of sections dealing with Design, Materials and Sitework.


In this Chapter, the Technical Requirements, which MUST be met by the Builder, are in red.


Most of the Chapters consist of detailed Performance Standards in black, for each Design, Materials or Sitework section. Each section contains clauses which are prefixed by the Chapter number and D, M or S for Design, Materials or Sitework, respectively.

Alternative standards of performance will be acceptable ONLY if, in the opinion of NHBC, the Technical Requirements are met and the standard achieved is not lower than the stated Performance Standard.

If the Performance Standards are followed the Technical Requirements will be met.


Guidance on how the Performance Standard may be met is in light blue.

Diagrams may contain text in red. This is to highlight points and has no mandatory status.

Guidance is based on normal construction procedures and recommended practices which have been shown to be satisfactory and acceptable over time. NHBC will consider alternative methods to meet specific requirements, subject to prior consultation and evaluation.


The Technical Requirements, Performance Standards and Guidance do not form a complete specification and should not be used as such in contracts.

Individual Chapters cover, as far as practical, the requirements for particular elements of construction. To avoid repetition, some cross-referencing is made to other Chapters, where necessary.


Occasionally, there may be disagreements on how Technical Requirements and Performance Standards are to be interpreted. Such cases are usually resolved through further consultation, failing which NHBC will exercise its right to decide, subject to appeal to an arbitrator under NHBC Rules.


Where required by NHBC, Builders must make samples of materials available for testing to ensure that they comply with Technical Requirement R3. Tests acceptable in the UK must be used when applicable. The costs of any test shall be met by the Builder if it proves non-compliance and by NHBC if it proves compliance. Materials which do not comply shall, if necessary, be removed from the site.


Where NHBC Standards refer to British Standards or Codes of Practice, other authoritative documents or technical approval certification, the documents shall be the editions current at the time of Building Regulation approval, unless other recommendations are made by NHBC in writing.

The British Standards and Codes of Practice referred to in the NHBC Standards include British Standards or Codes of Practice and those made under the Construction Products Directive (89/106/EEC) and, in particular, appropriate European Technical Specifications approved by a European Committee for Standardisation (CEN).

The UK accepts harmonised standards which are dual numbered British Standards. These have numbers issued by the British Standards Institution (BSI), the International Standards Organisation (ISO) and a European Committee for Standardisation (CEN).

Example: BS EN ISO 9000-1

Unless NHBC provides written notification to the contrary, the use of guidance in authoritative documents not mentioned in the NHBC Standards, such as BRE Digests, can be considered for acceptance.


All measurements shall be within acceptable tolerances. Where it is applicable, account should be taken of Chapter 1.2 'A Consistent approach to finishes'. In other situations, tolerances will be those currently acceptable in the industry.


NHBC is indebted to the members of the Standards Review Group, Scottish and Northern Ireland Technical Sub Committees and Standards Committee for all their work.

NHBC also wishes to acknowledge the help given by consultants, authoritative organisations, individuals and staff.

A list of the organisations who nominate representatives to the Standards Committee, Scottish Technical Sub Committee and the Northern Ireland Technical Sub Committee is shown below.

Standards Committee

Chartered Institute of Building
Construction Products Association

Federation of Master Builders

Home Builders Federation

Institution of Civil Engineers
DCLG (Department for Communities and Local Government) (observer)
Royal Institute of British Architects

Scottish Technical Sub Committee

Homes for Scotland

Royal Incorporation of Architects in Scotland/Royal Institute of British Architects

Scottish Branch of the Chartered Institute of Building

Scottish Branch of the Royal Institution of Chartered Surveyors

Scottish Group of the Association of Consulting Engineers

Northern Ireland Technical Sub Committee

Construction Employers Federation
Royal Society of Ulster Architects


The Builder shall ensure that the work complies with the Technical requirements

Statutory requirements Work shall comply with all relevant Building Regulations and other statutory requirements relating to the completed construction work

In England, Wales and the Isle of Man, NHBC will generally accept work that accords with the relevant Approved Documents and their supporting documents. Exceptions would be where NHBC has a higher standard or where there is doubt as to whether the recommendation in the Approved Document is appropriate to a particular application.

In Scotland and Northern Ireland, account shall be taken of the relevant Building Standards and Regulations.

Building Regulations and rules of Statutory Authorities primarily cover matters of health and safety. Matters affecting durability and serviceability also need to be considered.

NHBC Standards do not apply to:

  • health and safety matters relating to building operations
  • handling and use of certain building materials
  • planning matters.
Design requirement Design and specification shall provide satisfactory performance

Account shall be taken of:
The land quality, including:
geology and ground conditions
workings below ground
previous use of the site
any other aspect, on or adjacent to the site, which could affect the design.
Where appropriate, the land quality will have to be determined by a person acceptable to NHBC.
The structural adequacy of the works. The design, with appropriate factors of safety, should satisfactorily allow for loads during and after construction and for their transfer to the supporting structure, or foundation, without undue movement, including:
self weight
all imposed loads, including wind loads
construction loads.
The geographical location of the site, including:
The position of the dwelling on the site, especially with reference to the dwelling's exposure to the weather, including exposure at early stages in the development of a site, even if it is eventually protected by structures built later.
The position of building elements within the construction works, including the inter-relationship of materials and constructions.
The security of the dwellings.

Materials requirement All materials, products and building systems shall be suitable for their intended purpose

The structure of the home shall, unless specifically agreed otherwise in writing with NHBC, have a life of at least 60 years. Individual components and assemblies, not integral to the structure, may have a lesser durability and need planned maintenance, repair or replacement during that period.

Proper account shall be taken of the use and location of materials, products and building systems in relation to:

  • durability of both the structure and individual components and assemblies
  • geographical location
  • position on the site
  • position within the structure.
Materials, products and building systems will normally be acceptable if they comply with the following:
Functions critical to performance are: structure, fire resistance, weatherproofing, durability, thermal and sound insulation, services including heating appliances and flues.
Any of the following are acceptable:
performance in accordance with standards set by NHBC,
where no NHBC standard is set, compliance with the relevant British Standard or equivalent European Technical Specification approved by a Committee for Standardisation, provided they are used in accordance with the relevant Code of Practice,
compliance with standards not lower than those defined in a relevant British Standard specification or equivalent, provided their use is accepted by NHBC,
satisfactory assessment by an appropriate independent technical approvals authority accepted by NHBC, including: British Board of Agrément (BBA), Building Research Establishment (BRE), or a body authorised under Annex 4 to the Construction Products Directive,
use of materials and products in accordance with well established satisfactory custom and practice, provided that such custom and practice is acceptable to NHBC,
acceptance, in writing, by NHBC that the quality and use is satisfactory.
Compliance with the above acceptance criteria for critical functions or strictly in accordance with manufacturers' recommendations for the specific use.
Reclaimed materials may only be re-used with the prior agreement of NHBC. Independent certification of suitability may be required.
Reference should be made to R3(a), (iv).
Reference should be made to Chapter 2.3 'Timber preservation (natural solid timber)' (each section).


Equivalents to British Standards or technical approvals authority shall be those accepted in the UK.

Workmanship requirement All work shall be carried out in a proper, neat and workmanlike manner

The Builder shall ensure that:

the conditions of the materials, products and the completed work are satisfactory
appropriate precautions are taken to prevent damage
account is taken of the following:
the requirements of the design
suitable methods of unloading and handling
proper protection during storage
use of correct installation methods
protection against weather during construction (including excessive heat, cold, wetting or drying)
protection against damage by following trades.

Structural design requirement Structural design shall be carried out by suitably qualified persons in accordance with British Standards and Codes of Practice

The following shall be designed by Chartered Civil or Structural Engineers whose status (including professional indemnity insurance) is accepted by NHBC:

foundations on hazardous ground where the hazard makes special consideration necessary. This would not apply to matters for which NHBC sets Standards, such as building near trees, except where specified to the contrary
foundations and superstructure of every building over three storeys in height
certain types of foundations and retaining walls, as required in the individual Chapters of the NHBC Standards
any structural element which is not based on specific design criteria as laid down in the Chapters of the NHBC Standards
any dwelling not constructed in accordance with UK traditional practice.

Other structural elements may be designed by a Chartered Civil or Structural Engineer or others whose status (including professional indemnity insurance) is accepted by NHBC.

The structural design shall take account of the durability requirement in Technical Requirement R3 Materials requirement.

In England, Wales, Northern Ireland and the Isle of Man, structural design may be undertaken by the Builder's own Engineer or a Consulting Engineer employed by the Builder. Where specialist subcontractors undertake the design, it must be separately appraised by the Builder's own Engineer or by a Consulting Engineer employed by the Builder to ensure that the site investigation, choice of foundations, siting and construction of dwellings are properly taken into account and that the design is appropriate for the loading and conditions.

In Scotland, the Engineer shall be independent of the Builder and specialist subcontractor.

Account shall be taken of all parts of the following Eurocodes and their respective National Annexes.

BS EN 1990 (Eurocode 0) Basis of structural design
BS EN 1991 (Eurocode 1) Actions on structures
BS EN 1992 (Eurocode 2) Design of concrete structures
BS EN 1993 (Eurocode 3) Design of steel structures
BS EN 1995 (Eurocode 5) Design of timber structures
BS EN 1996 (Eurocode 6) Design of masonry structures
BS EN 1997 (Eurocode 7) Geotechnical design

Alternatively, designs in accordance with BS 8103 'Structural design of low rise buildings' will be acceptable.

The Builder shall:
  • require the Engineer to issue clear instructions for site personnel
  • not permit departure from the design without the Engineer's written consent
  • require the Engineer or his representative to carry out such inspections as may be required by NHBC to ensure the adequacy of the design and construction.
The Builder shall ensure that the Engineer visits the site during construction:
when the foundations have been designed under this Technical Requirement, or
when specifically required by NHBC in these Standards.

The Engineer shall satisfy himself that the design is suitable for the conditions encountered on the site of each dwelling.

When requested by NHBC, the Builder shall:
  • produce such design documents, calculations and prescribed forms of certification as NHBC requires for scrutiny
  • provide design documents and assembly instructions, solely for the use of NHBC staff
  • arrange for NHBC staff to have access to places where off-site fabrication is taking place.