BS 5628-3 and BS EN 1996 — designing with masonry

The two design routes

Masonry is designed either to the British Standard or to the Eurocode, and both appear in the approved documents:

• BS 5628-3:2001 — "Code of practice for use of masonry. Materials and components, design and workmanship". This is the route Approved Document C relies on for masonry in its damp-proofing and durability provisions.
• BS EN 1996 (Eurocode 6) — the European masonry design standard. Approved Document A's Section 1 lists BS EN 1996-1-1:2005+A1:2012 and BS EN 1996-2:2006 among the references for structural design, and Section 2 of that same document gives sizes of structural elements for certain residential and other small buildings of traditional construction.

So there are two things here that people often treat as one. The code of practice (BS 5628-3) deals with materials and components, design and workmanship — what the units and mortar have to be, and how the work is done. The design standards (BS 5628 parts 1 and 3, or the Eurocode 6 series) deal with what the wall can carry.

Status, and it matters: the whole BS 5628 family is now Withdrawn. British Standard 5628 was replaced by Eurocode 6, and BSI catalogues BS EN 1996-1-1:2022 and BS EN 1996-2:2024 as current, with PD 6697:2019 as the current UK recommendations for designing to them (all checked 22 September 2026). Approved Document C still cites BS 5628-3:2001, which is why it is named on this page — but that is a citation of what the document relies on, not a live standard to specify to.

Where Approved Document C uses BS 5628-3

AD C leans on BS 5628-3 in several places rather than spelling everything out itself:

• It gives BS 5628-3:2001 as a source of guidance on masonry materials and workmanship.
• On durability and exposure, it recommends assessing exposure using BS 8104 and then points to BS 5628-3 for what follows.
• Its paragraph on damp-proof courses, cavity trays and similar details refers to BS 5628-3 for appropriate installation guidance, and on mortar it refers to BS 5628-3 for the factors that govern choice.

In other words, for the parts of a wall that must keep water out and stay durable — the DPC, the cavity tray, the mortar — the code of practice is the detailed source, and the approved document is the route to it.

What a brick count cannot tell you

Our brick calculator answers one question: how many units and how much mortar, from the size of the wall and the module of the unit. That is arithmetic, and it is reliable arithmetic. It is not a masonry design. A count does not tell you:

• whether the wall needs to be thicker, or stiffened, to carry the load above it;
• what strength class of unit the exposure and the loads require;
• which mortar designation and which mix the code of practice calls for on that job;
• what movement joints, ties or restraint the wall needs.

Those come from a design. For a garden wall or a single skin of brickwork the answers may be simple; for anything load-bearing, or anything taller than the ordinary, they are not.

The unit standard itself

The specification of the brick as a manufactured product — its declared dimensions, its compressive strength, its durability and its dimensional tolerances — sits in its own product standard, which sets out the declared values the manufacturer must publish. We have deliberately not reproduced numbers from that standard here: it is a paid publication and we could not check them against the primary text. Ask your supplier for the declared values for the units you are buying, and check them against the design, rather than working from an assumed "standard brick" size.

Edition status — what the approved document cites, and what is current

An approved document names the edition of a standard that existed when it was written. That edition is not necessarily the current one. The table below sets out, for every standard this page relies on, the title as published, the edition the approved document cites, and the edition BSI catalogues today (22 September 2026). Where the cited edition is withdrawn, the page says so; where we could not confirm the replacement, no current edition is stated.

Source: BSI catalogue records read at knowledge.bsigroup.com on 22 September 2026. Each title, designation, status and date in the last two columns was read from the BSI catalogue page for that standard.

Last verified 22 September 2026. Every requirement quoted on this page was read from the primary source listed below on that date, not from a summary. If a figure could not be confirmed in the primary source it is not on this page.

Where these figures come from

• Approved Document C: Site preparation and resistance to contaminants and moisture, 2013 edition — references to BS 5628-3:2001 "Code of practice for use of masonry. Materials and components, design and workmanship" — GOV.UK publications, "Site preparation and resistance to contaminants and moisture: Approved Document C", checked 22 September 2026.
• Approved Document A: Structure, 2013 edition, Section 1 — references including BS EN 1996-1-1:2005+A1:2012 and BS EN 1996-2:2006 (Eurocode 6) — GOV.UK publications, "Structure: Approved Document A", checked 22 September 2026.
• BSI catalogue (“BSI Knowledge”) — product record for each standard listed above: title, current edition and status — knowledge.bsigroup.com, checked 22 September 2026.

Guidance only, not advice

This page is a plain-English summary of published regulations and standards, written to help you plan a job. It is not professional advice, it is not a substitute for the actual document, and it is not a building-control decision.

Building regulations are enforced by your local authority (or an approved inspector) and the facts of a particular job can change the answer. Confirm with your local building control before you start work, and where a job is structural, get it designed by a suitably qualified person. If this page and the source document disagree, the source document wins.