diff --git a/include/common/aabb.hh b/include/common/aabb.hh
index c5fa6398..ee5a1245 100644
--- a/include/common/aabb.hh
+++ b/include/common/aabb.hh
@@ -75,6 +75,14 @@ public:
     {
     }
 
+    template<typename Iter, std::enable_if_t<is_iterator_v<Iter>, int> = 0>
+    constexpr aabb(Iter start, Iter end) : aabb()
+    {
+        for (auto it = start; it != end; it++) {
+            *this += *it;
+        }
+    }
+
     constexpr bool operator==(const aabb &other) const { return m_mins == other.m_mins && m_maxs == other.m_maxs; }
 
     constexpr const value_type &mins() const { return m_mins; }
diff --git a/qbsp/brush.cc b/qbsp/brush.cc
index 59ba8f55..59f98c20 100644
--- a/qbsp/brush.cc
+++ b/qbsp/brush.cc
@@ -95,7 +95,7 @@ static void CheckFace(face_t *face, const mapface_t &sourceface)
         const qvec3d &p2 = face->w[(i + 1) % face->w.size()];
 
         for (auto &v : p1)
-            if (v > options.worldextent.value() || v < -options.worldextent.value())
+            if (fabs(v) > options.worldextent.value())
                 FError("line {}: coordinate out of range ({})", sourceface.linenum, v);
 
         /* check the point is on the face plane */
diff --git a/qbsp/csg4.cc b/qbsp/csg4.cc
index 4ebec62a..69cc4d39 100644
--- a/qbsp/csg4.cc
+++ b/qbsp/csg4.cc
@@ -300,9 +300,18 @@ static std::list<face_t *> CSGFace_ClipAgainstSingleBrush(std::list<face_t *> in
     return outside;
 }
 
-// fixme-brushbsp: determinism: sort `result` set by .map file order
+struct brush_ptr_less
+{
+    constexpr bool operator()(const brush_t *a, const brush_t *b) const
+    {
+        return a->file_order < b->file_order;
+    }
+};
+
+using brush_result_set_t = std::set<const brush_t *, brush_ptr_less>;
+
 // fixme-brushbsp: add bounds test
-static void GatherPossibleClippingBrushes_R(const node_t *node, const face_t *srcface, std::set<const brush_t *> &result)
+static void GatherPossibleClippingBrushes_R(const node_t *node, const face_t *srcface, brush_result_set_t &result)
 {
     if (node->planenum == PLANENUM_LEAF) {
         for (auto *brush : node->original_brushes) {
@@ -322,9 +331,9 @@ GatherPossibleClippingBrushes
 Starting a search at `node`, returns brushes that possibly intersect `srcface`.
 ==================
 */
-static std::set<const brush_t *> GatherPossibleClippingBrushes(const mapentity_t* srcentity, const node_t *node, const face_t *srcface)
+static brush_result_set_t GatherPossibleClippingBrushes(const mapentity_t* srcentity, const node_t *node, const face_t *srcface)
 {
-    std::set<const brush_t *> result;
+    brush_result_set_t result;
 
     GatherPossibleClippingBrushes_R(node, srcface, result);
 
diff --git a/qbsp/portals.cc b/qbsp/portals.cc
index 19d46bfb..5724d06a 100644
--- a/qbsp/portals.cc
+++ b/qbsp/portals.cc
@@ -436,8 +436,7 @@ void MakeTreePortals_r(node_t *node, portalstats_t &stats)
 
     for (int i = 0; i < 3; i++)
     {
-        // fixme-brushbsp: use proper map bounds
-        if (node->bounds.mins()[i] < -8000 || node->bounds.mins()[i] > 8000)
+        if (fabs(node->bounds.mins()[i]) > options.worldextent.value())
         {
             printf ("WARNING: node with unbounded volume\n");
             break;
diff --git a/qbsp/solidbsp.cc b/qbsp/solidbsp.cc
index cbd4fc3e..12916424 100644
--- a/qbsp/solidbsp.cc
+++ b/qbsp/solidbsp.cc
@@ -558,7 +558,7 @@ bool WindingIsHuge(const winding_t &w)
 {
     for (size_t i = 0; i < w.size(); i++) {
         for (size_t  j = 0; j < 3; j++)
-            if (w[i][j] < -8000 || w[i][j] > 8000)
+            if (fabs(w[i][j]) > options.worldextent.value())
                 return true;
     }
     return false;