Four approvals and one building: landlord consent if you lease, planning where the site needs it, building control always, and an Ofsted premises change at the end. Between those sits the building itself, which for a modular room means weeks in a factory and days on site. Here is the whole process in order, with the timescales that actually apply.
| Step | What happens | Typical time |
|---|---|---|
| 1. Numbers | Confirm the places and age groups you want to add; EYFS space standards turn that into a room size | Days |
| 2. Landlord consent | Leased premises only: put drawings in front of the landlord or agent early | 2 to 8 weeks, runs in parallel |
| 3. Layout & quote | Room plan drawn to your numbers, fixed quote issued | About a week |
| 4. Planning check | Confirm whether the extension needs an application or proceeds under permitted development | Days to check; determination typically 8 weeks where an application is needed |
| 5. Building control | Application submitted from the drawing pack: structure, thermal, fire, ventilation | Runs alongside manufacture |
| 6. Manufacture + groundworks | Building built and fitted out off site while the base and services are prepared | 8 to 14 weeks |
| 7. Installation | Delivery, crane set, connection, commissioning; fenced and scheduled around sessions | Days |
| 8. Sign-off & Ofsted | Building control completion evidence collected; Ofsted notified of the premises change, registration conditions varied where numbers change | 2 to 6 weeks |
Two, in our experience. First, landlord consent on leased premises: it is often slower than any statutory process, so it should start first, not last, and a relocatable modular building is usually an easier consent conversation than a permanent extension because reinstatement stays possible. Second, the assumption that a small building means no building control: a room children occupy needs the full sign-off, and Ofsted will expect to see the completion evidence. The premises requirements themselves are covered in the Ofsted premises checklist.
On a design, supply and install project you own the decisions and the registrations: the numbers, the landlord conversation, and the Ofsted notification, because only the registered provider can make it. We carry the technical load: EYFS-sized layouts, planning-ready drawings, the building control package, manufacture, groundworks on the turnkey option, installation and the completion documentation. The service, layouts and build ranges are on the nursery buildings page.
Work backwards from the term you want the places live: allow 2 to 6 weeks for registration and sign-off, 8 to 14 weeks for manufacture, and the design and approvals period in front of that. In practice that means starting design work in the autumn or winter for places you want to sell the following September, and earlier where planning permission is required.
About Cabinworx. Cabinworx designs, supplies and installs steel and timber frame modular buildings across the UK, from welfare and canteen blocks to classrooms, nursery rooms and sanitary buildings. Steel cabins come in our Classic and Plus ranges, timber frame in Standard and Premier, and every building is delivered and installed on a prepared base by our team.
Nursery buildings: design, supply & installTell us the places you want to add, the age groups, and whether the premises are owned or leased. We come back with a room plan and a fixed quote, usually within two working days.