Constraint recipe
A double-period lesson uses two adjacent teaching periods as one session, common for labs, workshops, and practical work. Splitting it would break the activity. Because both periods must be free together, blocks are harder to place than single lessons. Check teacher, class, room, and equipment availability across the full block before you add more block rules.
Key takeaways
- A block needs two adjacent periods with the same teacher, class, and room.
- Some blocks are curriculum requirements; others are preferences.
- Check availability across both periods, not just the first.
- Too many blocks can crowd the week and limit spread.
Why blocks are harder than single lessons
A single lesson can use any free period. A double period needs two neighboring periods where the teacher, class, and room are all free. That smaller set of options is why lab and workshop sessions are often scheduled first.
Mark a block as **hard** when splitting it would make the session unusable. Keep it **soft** when adjacent placement is desirable but not required.
What to decide before building the timetable
List which subjects truly need blocks and which could run as singles. A whole course does not need every session doubled; often only practical weeks do.
The curriculum rules guide explains how blocks and spread preferences fit together.
What to do next
- List subjects or activities that need adjacent periods.
- Mark mandatory blocks separately from preferred blocks.
- Check teacher, class, room, and equipment for both periods in the block.
- Place the most constrained blocks before flexible single lessons.
- Review whether blocks crowd one day or overload one teacher.
- Relax preferred blocks before changing mandatory curriculum blocks.
Common mistakes
- Blocking every lesson in a subject when only some sessions need it
- Checking room availability for period one but not period two
- Adding blocks after generation and forcing a full rebuild
Quick answers
Should double periods be scheduled first?
Often yes, especially when they need scarce rooms or specialist teachers. Test the tightest blocks early.
Can a double period be soft?
Yes. If adjacent placement is desirable but not required, treat it as a preference rather than a must-have rule.