John Smith, technical director at Donaldson Timber Systems, explains that the key to achieving maximum benefit from offsite manufacturing is having the right technical conversations as early as possible
Early in my career, a senior member of a large customer told me it can cost £50 to change a drawing, £5000 to fix an issue on site, and £50,000 to fix an issue in an occupied building. That message has stuck with me for 30-years and is as relevant today as it was then.
Early engagement isn’t the same as early collaboration. The construction industry has talked about early engagement for years, but simply bringing a specialist supplier into a conversation earlier isn’t enough.
Early collaboration has real value when specialist knowledge can influence decisions while those decisions can still be changed.
Optimising timber frame design
Timber frame isn’t simply a structural package you can insert into a fully developed design without consequence. Architecture, structural engineering, fabric performance, manufacturing, logistics and construction all interact. If you change something in one area, it can affect another. The opportunity is not simply to establish whether a design can be delivered in timber frame; it is to establish how that design can be optimised to deliver the most efficient building that incorporates timber frame. Those are very different questions.
The earlier we become involved, the more opportunity there is to consider the fundamentals. Structural walls and spans; load paths; fabric performance; interfaces with other materials and services; tolerances; repeatability; suitability for efficient design, transport and assembly on site; individually, some of these decisions can appear relatively small. Collectively, they determine how efficiently a building can be engineered, manufactured and constructed. As a project progresses, the freedom to change them shrinks significantly.
Technical certainty isn’t something you can simply check into a project at the end of design; you have to design it in from the beginning.
Designing for timber frame, rather than converting to it, is one of the biggest opportunities I see. A building can be capable of being constructed using timber frame without necessarily having been designed to make the best use of timber frame. Only when early collaboration has been embedded in the process do we realise the maximum benefit of the building system.
Performance can’t be considered in isolation
Good technical collaboration helps the project team achieve the design intent with greater confidence about how it will be delivered. This becomes increasingly important as expectations of building performance increase.
Structure, insulation, airtightness, thermal bridging, services and interfaces are all interconnected. A decision made to improve one aspect of performance can have consequences elsewhere. The technical challenge is not simply achieving individual values on a specification sheet but understanding how the complete building fabric works as a system and how it will be manufactured and assembled consistently enough to deliver the intended performance.
One of the clearest benefits of bringing manufacturing and construction knowledge into technical discussions earlier is improving buildability. Buildability is often treated as something that belongs to the construction phase. It doesn’t. By the time a buildability issue appears on site, the range of available solutions has usually narrowed considerably. Design buildability into a project, not check it at the end of the design process.
With offsite manufacture, the timber frame programme doesn’t begin when installation starts. Design information must be coordinated and approved; engineering must be completed; materials must be procured; manufacturing must be scheduled; and logistics and installation must align with site readiness. These aren’t separate activities; they are one connected process.
If we understand the required construction sequence early enough, we can work backwards and establish what needs to happen and when, across design, approval, procurement and manufacture. That gives everyone greater visibility of the critical decisions. More importantly, it lets us address risks while there is still time to act.
Earlier collaboration has to earn its place. There is an important responsibility on specialist suppliers here too. We have to make it valuable. That means bringing technical knowledge that improves the project. That could mean identifying an opportunity, challenging an assumption or explaining the consequences of a decision before it is made. Sometimes, the most valuable thing we can do is identify something that won’t work as intended before significant time and cost have been committed.
Customers shouldn’t need to become timber frame experts in order to work successfully with timber frame. As specialists, it’s our job to make that expertise accessible to the wider project team.
The best time to solve a technical problem is before it becomes one. Earlier collaboration doesn’t eliminate risk; construction is too complex for that. But it does give us a much greater opportunity to identify risk, understand the consequences of decisions and optimise the building while there is still freedom to act. We spend a great deal of time in construction managing what happens later. We should spend more time influencing what happens earlier, because better outcomes start with early conversations.
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