A cladding board that no longer exists
The technical design for a new house reuses much of the specification from a similar project two years ago. The cladding board, the roof membrane, the rooflights and the ironmongery are the same because they worked well. At tender, the contractor points out that the cladding board has been discontinued, the rooflight model has changed its sizes, and the membrane's installation guidance has been updated. Now the specification needs revising under time pressure, and alternatives need checking.
The information was all out there. It just was not checked, because nobody's job is to watch products the practice has used before.
Why product knowledge goes stale
Practices build up favourite products over years. That knowledge lives in old specifications, in PDFs saved in project folders, and in the heads of senior staff. Some practices use a specification platform such as NBS Chorus, which helps with the clauses, but the practice's own choices and experiences of each product still tend to live elsewhere. Manufacturers change ranges, update certifications and discontinue products without telling past specifiers.
- Product data sheets are saved per project and never refreshed.
- Past specifications are copied forward without checking products.
- There is no record of why a product was chosen or how it performed.
- Discontinued or changed products surface at tender or on site.
- Certification or test documents may have been updated since last use.
What stale product data costs
Late substitutions at tender or during construction mean unplanned work for the practice, questions about equivalence, and sometimes a lesser product going in. Where product performance matters for building regulations or fire safety, using out-of-date documents is a risk your team and advisers will want to avoid, and the product itself must be checked by your designers. And the practice's hard-won knowledge of what works is lost every time a senior person leaves.
A practice product library that watches for change
- Products are gathered from your past specifications and project folders into one library, with manufacturer, product, range, the documents you relied on and the projects they were used on.
- Each product gets notes from the team: why it was chosen, how it performed on site, any issues.
- On a schedule, manufacturer product pages and document links are checked for changes, such as a new data sheet, a changed certification document or a product page that has disappeared.
- Changes are flagged on the library entry, with the old and new documents kept side by side.
- When a specification is being prepared, products carried forward from previous projects are listed with their status: unchanged, changed or possibly discontinued.
- The specifier reviews flagged items and updates the specification, and the library records the decision.
The library alerts you to change. Whether a product is suitable for a particular project, and whether it meets the relevant requirements, is the designer's decision.
Library entries at a glance
| Product type | Last used | Status | Team notes |
|---|---|---|---|
| Cladding board | Two years ago | Possibly discontinued | Good finish, fixings awkward |
| Rooflight | Last year | Sizes changed | Reliable delivery |
| Roof membrane | This year | New installation guide | No issues |
Illustrative entries only.
Specifying with current information
Specifications carried forward from past projects are checked before they go out, not at tender. The practice keeps its knowledge of what works, with notes from site, even when people move on. And junior staff can see why a product was chosen and how it performed, which makes their own specifying better.
Is this your practice's product knowledge?
- Product data sheets live in old project folders.
- Specifications are copied forward without checking products.
- Discontinued products have been found at tender.
- Knowledge of what works sits with a few senior people.