Masonry support is almost always priced before it can be fully designed. That is not a criticism of anyone’s process. It is a sequencing reality: packages are tendered when commercial certainty is needed, and a lot of the information a support design requires arrives later than that. Masonry support design development is what happens in that gap
So the useful commercial question is not “what does this cost”. It is: who absorbs the difference between what was assumed at tender and what the design turns out to require?
That difference is design development. On most projects it is real, it is quantifiable after the fact, and it is rarely allocated in advance.
Why the price has to come before the design
Masonry support depends on a specific set of inputs. At tender, the typical position looks like this:
| The design needs | At tender you often have |
|---|---|
| Slab edge position and as-built tolerance | A drawn position and a specification tolerance class |
| Confirmed brick dimensions and coursing | A brick range, or a performance description |
| Final cavity width and insulation build-up | A build-up still subject to thermal or fire review |
| Confirmed loads, including parapets and feature brickwork | Loads carried over from an earlier design stage |
| Frame type, grid and connection detail | A frame design in progress, or a contractor’s design |
| Movement joint strategy | Joint positions indicated, and sometimes not |
Every row is a normal part of design development. Each one also changes the support design.
This is not simply an industry habit. The RIBA Plan of Work 2020 says as much itself. Its guidance warns that where Stage 3 deliverables are used for tender purposes, that information rarely carries enough detail for a robust tender to be prepared, even when it is fully coordinated. It also places specialist subcontractor design work at Stage 4 — after the point at which many packages have already been priced.
So the sequencing is not a failure of anyone’s process. It is what the industry’s own framework describes. That makes the allocation question more pressing rather than less: if the gap is expected, the treatment of the risk arising from it should be agreed in advance too.
None of this is avoidable. What is avoidable is the situation where the tender treats these as settled, the design later shows they were not, and nobody agreed in advance what happens next.
This is the commercial face of a question we looked at separately, the one about who is actually responsible for the masonry support design. An unallocated design item and an unpriced development risk are usually the same item, viewed by two different people.
The changes that move the number
Small changes on an architectural or structural revision can be significant changes to a support package.
- Brick dimensions. A change in brick format changes coursing, which changes support levels and can change the whole vertical setting-out of the façade.
- A change of brick type. Moving from a standard extruded brick to a handmade brick, a brick slip system or a stone facing changes weight, coursing tolerance and often the support principle itself.
- Cavity width. Increasing the cavity increases the eccentricity of the load, which changes bracket capacity, bracket spacing and the demand on the fixing.
- Insulation build-up. The same effect as cavity width, and it usually arrives via a thermal or fire review rather than a structural one.
- Slab edge position or level. Either as a design change or as an as-built condition.
- Revised loads. Including additions such as parapets, feature banding, deeper reveals or soffit brickwork.
- New or moved openings. Each one is a local redesign.
- Programme changes. Which affect sequencing, temporary conditions and sometimes movement provision.
Individually, each is a drawing revision. Cumulatively, they can change the quantity, type and complexity of what has to be manufactured.
Rate versus price
This is the point most worth being clear about, because it causes more commercial difficulty than anything else on the package.
A rate applied to an area – cost per linear metre, or per square metre of façade – implicitly assumes a bracket density and a component mix. But bracket density is an output of the design, not an input. It follows from the load, the cavity, the eccentricity, the substrate and the fixing capacity.
A rate is not a price. It is a price conditional on an assumption about the design.
If the assumption holds, the rate holds. If the cavity grows, the brick gets heavier, or the substrate turns out to have less fixing capacity than assumed, the rate is unchanged and the quantity is not.
This is why two tenders can show the same rate and produce very different final accounts. Comparing rates without comparing assumptions tells you very little.
Where masonry support design development risk actually sits
The allocation of design development risk changes with the contract, and it is worth being explicit about which one you are in.
Traditional. The design is developed by the client’s team, and the support design is usually a specialist’s contribution within that. Development risk tends to sit with the client, expressed through variations, unless the specialist’s appointment says otherwise.
Design and build. Development risk transfers to the contractor at contract, including risk arising from information that was incomplete at the point of transfer. The Employer’s Requirements do a lot of work here. Where they are performance-based and the support arrangement is undefined, the contractor has taken on a design they cannot yet quantify.
Contractor’s design portion. The narrowest and often the clearest position, but only if the CDP scope is defined by outcome as well as by element. “Masonry support design” as a CDP item still leaves open who owns the frame interface, the fixing design and the load verification.
The route does not remove the risk. It determines who is holding it, and whether they knew that when they priced.
What good looks like
A well-handled package usually has four things in place. None of them is complicated.
- Stated assumptions The tender records what was assumed about brick, cavity, loads, substrate and tolerance. This is not a defensive exercise. It is the only way a later change can be identified as a change.
- A defined information release schedule Which information is needed, by whom, and by when. Design development risk is largely a function of information arriving later than the design needed it.
- An agreed change mechanism What constitutes a change, who assesses it, and how quickly. Agreed before it is needed, rather than during.
- A visible risk allowance An allowance identified as such can be managed, released or spent deliberately. An allowance buried in a rate can only be argued about.
Questions worth asking at tender review
- What has been assumed about brick type, coursing, cavity width and loads?
- What is excluded, and where does the excluded scope sit instead?
- What triggers a change under this pricing, and what does not?
- Is the design based on the drawn frame, or on a survey of the built frame?
- Who verifies the supporting structure’s capacity to take the load?
- If the substrate delivers less fixing capacity than assumed, whose risk is that?
Six questions. They take a few minutes at tender review and can save a great deal later.
What this means for you
If you are pricing
The comparison that matters is not rate against rate, but assumption against assumption. A tender that states its assumptions clearly is giving you a more useful document than one that looks more competitive but says nothing.
If you are contracting
The risk you have taken on in masonry support design development is proportional to the gap between the information available at contract and the information the design needs. Identifying that gap is a pre-contract activity, not a post-contract discovery.
If you are designing
The assumptions recorded at tender become the baseline against which every later revision is measured. Anything you can confirm earlier — brick, cavity, loads — reduces someone’s risk, and eventually reduces the project’s cost.
There is a related question sitting just downstream of this one: when a saving is proposed, is it a genuine reduction in cost or a relocation of it? We look at that separately later in this series, because it deserves more than a paragraph.
This is the territory FIRMA works in. Because our masonry support systems, windposts and brick slip soffit systems are designed in-house, the assumptions behind a price are ours to state rather than ours to inherit, which is what makes a later change identifiable as a change. Where a project team wants the support package’s assumptions on the table before tender, that is a conversation we would rather have early.
This article discusses general commercial and contractual principles. It is not legal or contractual advice, and it is not a substitute for project-specific guidance. For advice on a particular masonry support package, talk to the FIRMA technical team.
References and further reading
- JCT — Design and Build Contract and Contractor’s Designed Portion provisions. Guidance on design responsibility and risk allocation available at jctltd.co.uk.
- NEC4 — Engineering and Construction Contract, in particular the treatment of compensation events and contractor design. Available at neccontract.com.
- RICS — New Rules of Measurement (NRM) and guidance on risk allowances in cost planning. Available at rics.org.
- RIBA Plan of Work 2020 — stage-by-stage information exchanges, useful for defining when design information should be available. Available at architecture.com.
- The Building Regulations etc. (Amendment) (England) Regulations 2023 — dutyholder competence, and the requirement to allocate sufficient time and resource to design work. Available at legislation.gov.uk.
- BS 8539:2012+A1:2021 — Code of practice for the selection and installation of post-installed anchors in concrete and masonry. BSI. Relevant to who carries the cost of anchor testing when fixing quantities change. BSI Knowledge
- PD 6697:2019 — Recommendations for the design of masonry structures to BS EN 1996-1-1 and BS EN 1996-2. BSI. BSI Knowledge
- BS EN 845-1:2013+A1:2016 — Specification for ancillary components for masonry. BSI. Relevant to what product conformity does and does not cover. BSI Knowledge
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