diff --git a/djangorota/rota/forms.py b/djangorota/rota/forms.py
index 4860b4e..452a9fd 100644
--- a/djangorota/rota/forms.py
+++ b/djangorota/rota/forms.py
@@ -101,7 +101,9 @@ class RotaScheduleForm(forms.ModelForm):
 
         # Expose a small set of RotaBuilder constructor arguments on the form
         # so they can be set per-rota. These are stored inside `instance.options`
-        # and will be passed through by `RotaSchedule.to_rota_builder()`.
+        # and will be passed through by `RotaSchedule.to_rota_builder()` as
+        # legacy builder args (the remaining keys in `options` are treated as
+        # constraint configuration for `RotaConstraintOptions`).
         builder_args = {
             "balance_offset_modifier": {"type": "int", "default": 1, "help": "Balance offset modifier used by the builder"},
             "ltft_balance_offset": {"type": "int", "default": 1, "help": "LTFT balance offset used by the builder"},
diff --git a/djangorota/rota/models.py b/djangorota/rota/models.py
index 1f274d6..ba22f3f 100644
--- a/djangorota/rota/models.py
+++ b/djangorota/rota/models.py
@@ -57,10 +57,38 @@ class RotaSchedule(models.Model):
 		delta = self.end_date - self.start_date
 		weeks_to_rota = max(1, int(delta.days // 7))
 
-		# Allow passing options directly if they match RotaBuilder kwargs
-		rb_kwargs = dict(self.options or {})
+		# Build kwargs for RotaBuilder from any explicit builder args stored in
+		# `self.options` (kept for backward compatibility), and treat the
+		# remaining keys as constraint options which should map to
+		# `RotaConstraintOptions`.
+		opts = dict(self.options or {})
+		builder_keys = [
+			"balance_offset_modifier",
+			"ltft_balance_offset",
+			"use_previous_shifts",
+			"use_shift_balance_extra",
+			"use_bank_holiday_extra",
+			"allow_force_assignment_with_leave_conflict",
+		]
+		rb_kwargs = {k: opts.pop(k) for k in builder_keys if k in opts}
 		rb = RotaBuilder(start_date=self.start_date, weeks_to_rota=weeks_to_rota, name=self.name, **rb_kwargs)
 
+		# If the rota package exposes a typed RotaConstraintOptions model, use it
+		# to validate/coerce the remaining `opts` and attach it to the builder.
+		try:
+			RotaConstraintOptions = getattr(mod, "RotaConstraintOptions")
+			if opts:
+				# validate raw JSON into the typed model
+				opts_model = RotaConstraintOptions.model_validate(opts)
+			else:
+				opts_model = RotaConstraintOptions()
+			# attach the typed model to the builder (overrides defaults)
+			setattr(rb, "constraint_options_model", opts_model)
+		except Exception:
+			# If the model isn't available or validation fails, keep builder
+			# defaults and proceed (backwards compatible behaviour).
+			pass
+
 		# Add shifts (expecting list of dicts compatible with SingleShift)
 		shifts_objs = []
 		for s in self.shifts or []: