diff --git a/src/applications/drydock/blueprint/DrydockAlmanacServiceHostBlueprintImplementation.php b/src/applications/drydock/blueprint/DrydockAlmanacServiceHostBlueprintImplementation.php
--- a/src/applications/drydock/blueprint/DrydockAlmanacServiceHostBlueprintImplementation.php
+++ b/src/applications/drydock/blueprint/DrydockAlmanacServiceHostBlueprintImplementation.php
@@ -45,6 +45,16 @@
     return true;
   }
 
+  public function shouldAllocateSupplementalResource(
+    DrydockBlueprint $blueprint,
+    DrydockResource $resource,
+    DrydockLease $lease) {
+    // We want to use every host in an Almanac service, since the amount of
+    // hardware is fixed and there's normally no value in packing leases onto a
+    // subset of it. Always build a new supplemental resource if we can.
+    return true;
+  }
+
   public function canAllocateResourceForLease(
     DrydockBlueprint $blueprint,
     DrydockLease $lease) {
diff --git a/src/applications/drydock/blueprint/DrydockBlueprintImplementation.php b/src/applications/drydock/blueprint/DrydockBlueprintImplementation.php
--- a/src/applications/drydock/blueprint/DrydockBlueprintImplementation.php
+++ b/src/applications/drydock/blueprint/DrydockBlueprintImplementation.php
@@ -139,6 +139,38 @@
     DrydockResource $resource,
     DrydockLease $lease);
 
+  /**
+   * Return true to try to allocate a new resource and expand the resource
+   * pool instead of permitting an otherwise valid acquisition on an existing
+   * resource.
+   *
+   * This allows the blueprint to provide a soft hint about when the resource
+   * pool should grow.
+   *
+   * Returning "true" in all cases generally makes sense when a blueprint
+   * controls a fixed pool of resources, like a particular number of physical
+   * hosts: you want to put all the hosts in service, so whenever it is
+   * possible to allocate a new host you want to do this.
+   *
+   * Returning "false" in all cases generally make sense when a blueprint
+   * has a flexible pool of expensive resources and you want to pack leases
+   * onto them as tightly as possible.
+   *
+   * @param DrydockBlueprint The blueprint for an existing resource being
+   *   acquired.
+   * @param DrydockResource The resource being acquired, which we may want to
+   *   build a supplemental resource for.
+   * @param DrydockLease The current lease performing acquisition.
+   * @return bool True to prefer allocating a supplemental resource.
+   *
+   * @task lease
+   */
+  public function shouldAllocateSupplementalResource(
+    DrydockBlueprint $blueprint,
+    DrydockResource $resource,
+    DrydockLease $lease) {
+    return false;
+  }
 
 /* -(  Resource Allocation  )------------------------------------------------ */
 
diff --git a/src/applications/drydock/storage/DrydockBlueprint.php b/src/applications/drydock/storage/DrydockBlueprint.php
--- a/src/applications/drydock/storage/DrydockBlueprint.php
+++ b/src/applications/drydock/storage/DrydockBlueprint.php
@@ -278,6 +278,15 @@
     return $interface;
   }
 
+  public function shouldAllocateSupplementalResource(
+    DrydockResource $resource,
+    DrydockLease $lease) {
+    return $this->getImplementation()->shouldAllocateSupplementalResource(
+      $this,
+      $resource,
+      $lease);
+  }
+
 
 /* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
 
diff --git a/src/applications/drydock/worker/DrydockLeaseUpdateWorker.php b/src/applications/drydock/worker/DrydockLeaseUpdateWorker.php
--- a/src/applications/drydock/worker/DrydockLeaseUpdateWorker.php
+++ b/src/applications/drydock/worker/DrydockLeaseUpdateWorker.php
@@ -306,6 +306,7 @@
     $allocated = false;
     foreach ($resources as $resource) {
       try {
+        $resource = $this->newResourceForAcquisition($resource, $lease);
         $this->acquireLease($resource, $lease);
         $allocated = true;
         break;
@@ -319,6 +320,10 @@
         // got around to acquiring it, we just got unlucky. We can yield and
         // try again later.
         $yields[] = $ex;
+      } catch (PhabricatorWorkerYieldException $ex) {
+        // We can be told to yield, particularly by the supplemental allocator
+        // trying to give us a supplemental resource.
+        $yields[] = $ex;
       } catch (Exception $ex) {
         $exceptions[] = $ex;
       }
@@ -791,6 +796,73 @@
     }
   }
 
+  private function newResourceForAcquisition(
+    DrydockResource $resource,
+    DrydockLease $lease) {
+
+    // If the resource has no leases against it, never build a new one. This is
+    // likely already a new resource that just activated.
+    $viewer = $this->getViewer();
+
+    $statuses = array(
+      DrydockLeaseStatus::STATUS_PENDING,
+      DrydockLeaseStatus::STATUS_ACQUIRED,
+      DrydockLeaseStatus::STATUS_ACTIVE,
+    );
+
+    $leases = id(new DrydockLeaseQuery())
+      ->setViewer($viewer)
+      ->withResourcePHIDs(array($resource->getPHID()))
+      ->withStatuses($statuses)
+      ->setLimit(1)
+      ->execute();
+    if (!$leases) {
+      return $resource;
+    }
+
+    // If we're about to get a lease on a resource, check if the blueprint
+    // wants to allocate a supplemental resource. If it does, try to perform a
+    // new allocation instead.
+    $blueprint = $resource->getBlueprint();
+    if (!$blueprint->shouldAllocateSupplementalResource($resource, $lease)) {
+      return $resource;
+    }
+
+    // If the blueprint is already overallocated, we can't allocate a new
+    // resource. Just return the existing resource.
+    $remaining = $this->removeOverallocatedBlueprints(
+      array($blueprint),
+      $lease);
+    if (!$remaining) {
+      return $resource;
+    }
+
+    // Try to build a new resource.
+    try {
+      $new_resource = $this->allocateResource($blueprint, $lease);
+    } catch (Exception $ex) {
+      $blueprint->logEvent(
+        DrydockResourceAllocationFailureLogType::LOGCONST,
+        array(
+          'class' => get_class($ex),
+          'message' => $ex->getMessage(),
+        ));
+
+      return $resource;
+    }
+
+    // If we can't actually acquire the new resource yet, just yield.
+    // (We could try to move forward with the original resource instead.)
+    $acquirable = $this->removeUnacquirableResources(
+      array($new_resource),
+      $lease);
+    if (!$acquirable) {
+      throw new PhabricatorWorkerYieldException(15);
+    }
+
+    return $new_resource;
+  }
+
 
 /* -(  Activating Leases  )-------------------------------------------------- */