The short answer
It depends on how the building was designed and how it is looked after. A permanent modular classroom is designed and approved to stay like any other school building, while a relocatable unit is built to be moved and reused. Roofs, floors, windows and heating wear out first. Ask each supplier for the design life and the warranty in writing, and keep the maintenance record that makes a long life possible.
Most estates teams have inherited at least one mobile classroom that was meant to stay five years and is still there after thirty. That history makes people wary of modular buildings. The better question is not whether modular lasts, but what this particular building was designed for and how it will be maintained.
Permanent and relocatable are different products
Permanent modular buildings are designed, approved and built to stay on one site, with foundations, fabric and services to the same standards as a traditional building. They are bought, not hired, and they sit in the school’s estate like any other block.
Relocatable units are built to be lifted out, refurbished and used again. They are what most hire fleets and stock lists hold. They can serve for many years, but their design assumes moves and refurbishment along the way.
Ask each supplier which kind they are pricing, and for the design life of the structure in writing. Suppliers publish different figures, and a claim in a brochure is not the same as a design life on a specification.
What wears out first
The frame of a modular building rarely fails first. The parts that need attention are the same as on any building, only sometimes sooner on older relocatable units:
- Roof coverings. Membranes and seals at module joins are the most common source of leaks.
- Floors. Decks over a void can soften if water gets in; coverings wear in doorways.
- Windows and doors. Seals, ironmongery and closers in heavy use.
- Heating and ventilation. Electric panel heaters and older units’ ventilation are often the first things replaced.
- Steps, ramps and skirting. The connection to the ground takes knocks and weather.
How to make one last
- Keep the handover pack. Drawings, specifications, building control completion, warranties and manuals.
- Inspect yearly. Roof, joins, floor, steps and drainage, ideally with the rest of the estate.
- Fix water first. A small roof leak left over a winter becomes a floor replacement.
- Service the heating and ventilation on the manufacturer’s schedule.
- Record what is done. A maintenance history makes a unit easier to sell or move, and supports a funding case when it does reach the end.
Warranties
Warranty lengths vary. As one example, a supplier on a public sector framework states that purchases under it carry a minimum five-year warranty. Get the structural warranty, the defects period and any separate roof or equipment warranties in writing before you order, and note what maintenance keeps them valid.
When to replace
A modular classroom is at the end of its useful life when repairs cost more each year than the building is worth, or when it can no longer be made safe, warm and dry. At that point:
- an eligible school may have a condition case for CIF, which gives its highest priority to compliance and health and safety, provided the evidence shows the need;
- a refurbished replacement starts at a published £82,000 for a single classroom, building only;
- a new building starts at £108,000 for a single.
Before replacing, get a condition survey and price the repair. Sometimes a new roof and floor buy another decade.
Buying used? Ask about age
With used and refurbished classrooms, ask the year of manufacture, what was replaced in the refurbishment, and whether the unit meets current building regulations as installed. A well-kept older unit can be a better buy than a younger one with a poor history.