Construction Programme: Building Your Schedule

The most common source of stress on an extension project isn't the budget. It's the feeling that you don't know what should be happening right now, or what needs to happen next month for everything to line up.

Builders don't volunteer this information. They're thinking about their current task, not the seven things that need to happen in the right order over the coming months. That's your job, and it requires a construction programme.

What a Construction Programme Actually Is

A construction programme is a time-based plan of every phase in your build, with planned start and finish dates for each one. It's the time equivalent of a budget: the budget tracks money, the programme tracks weeks.

The simplest version is a spreadsheet with one row per task and columns for planned start, planned end, actual start, actual end, status, and notes. A Gantt chart is the visual version of this, showing tasks as horizontal bars against a time axis so you can see overlaps and gaps at a glance.

Don't confuse a construction programme with a schedule of works. A schedule of works is a list of what the builder will do and what it costs. It's a contract document. The programme is a time-tracking tool that sits alongside it. You need both, and they serve different purposes.

What Happens After Planning Permission Is Granted

Permission granted is a milestone, not a build start. Most homeowners move mentally from "permission granted" to "builder starts" as if they follow in quick succession. They don't. Between planning permission and a digger on site, the typical project has 4-6 months of sequential administration, legal process, and pre-construction logistics.

The gap is structural. Several steps must complete before groundwork can start, and they do not all run in parallel. They stack up.

Best case: 6-8 weeks. No party wall issues, no utility meter relocation, building notice route chosen (allows site start two working days after submission rather than waiting for full plans approval), builder free and contracted. This requires cooperative neighbours, no protected boundaries, and a builder with no prior commitments. Uncommon.

Typical case: 4-6 months. A full plans building control application takes 7-12 weeks. Party wall notice (where required) runs to 2-3 months including the service period and consent. Builder mobilisation adds 4-6 weeks from contract signing to site start. Some overlap is possible, but the total for most projects lands in the 4-6 month range.

Worst case: 9+ months. A party wall dispute with an uncooperative neighbour can run 4-6 months to resolve with a formal award. Full plans building control at the longer end. Builder delays of 2-3 months between other jobs. Utility meter relocation (if the meter sits in the extension footprint) adds a further 2-4 months from first contact with the network operator. These do not all overlap. A project facing several complications can wait the better part of a year from planning permission to groundworks starting.

Start the party wall process and the building control application the week your planning decision notice arrives. Not when you feel ready to build. The lead times are fixed whether you engage immediately or sit on the decision for three months. Every month of delay is a month added to your site start date.