diff --git a/_config/elemental.yml b/_config/extensions.yml
similarity index 51%
rename from _config/elemental.yml
rename to _config/extensions.yml
index e3f2c90..77a5eca 100644
--- a/_config/elemental.yml
+++ b/_config/extensions.yml
@@ -1,3 +1,13 @@
+---
+Name: frameworktest-extensions
+---
+SilverStripe\ORM\DataObject:
+  extensions:
+    - DevBuildGeneratorExtension
+SilverStripe\Assets\File:
+  extensions:
+    - BasicFieldsTestFileExtension
+
 ---
 Only:
   classexists: 'DNADesign\Elemental\Extensions\ElementalPageExtension'
diff --git a/_config/testpages.yml b/_config/testpages.yml
deleted file mode 100644
index 4fdd504..0000000
--- a/_config/testpages.yml
+++ /dev/null
@@ -1,6 +0,0 @@
----
-Name: frameworktestpages
----
-SilverStripe\Assets\File:
-  extensions:
-    - BasicFieldsTestFileExtension
diff --git a/code/BasicFieldsTestPage.php b/code/BasicFieldsTestPage.php
index 9ddf5dc..5f05c6d 100644
--- a/code/BasicFieldsTestPage.php
+++ b/code/BasicFieldsTestPage.php
@@ -110,11 +110,10 @@ class BasicFieldsTestPage extends TestPage
     {
         parent::requireDefaultRecords();
 
-        if ($inst = DataObject::get_one('BasicFieldsTestPage')) {
+        if ($inst = DataObject::get_one('BasicFieldsTestPage') && static::config()->get('regenerate_on_build')) {
             $data = $this->getDefaultData();
             $inst->update($data);
             $inst->write();
-
             TestCategory::create()->requireDefaultRecords();
             $cats = TestCategory::get();
             $firstCat = $cats->offsetGet(0);
diff --git a/code/Company.php b/code/Company.php
index d03d2ba..6b93f03 100644
--- a/code/Company.php
+++ b/code/Company.php
@@ -6,10 +6,10 @@ use SilverStripe\Assets\Image;
 use SilverStripe\Forms\DropdownField;
 use SilverStripe\ORM\HasManyList;
 use SilverStripe\ORM\ManyManyList;
-use SilverStripe\ORM\ValidationResult;
 use SilverStripe\ORM\DataObject;
 use SilverStripe\ORM\DB;
 use SilverStripe\AssetAdmin\Forms\UploadField;
+use SilverStripe\Versioned\RecursivePublishable;
 use SilverStripe\Versioned\Versioned;
 use RelationFieldsTestPage;
 use GridFieldTestPage;
@@ -120,11 +120,15 @@ class Company extends DataObject
     {
         parent::requireDefaultRecords();
         $companySet = static::get();
+        $data = $this->data();
+        if ($companySet->exists() && !static::config()->get('regenerate_on_build')) {
+            return;
+        }
         foreach ($companySet as $company) {
             $company->delete();
         }
 
-        foreach ($this->data() as $companyData) {
+        foreach ($data as $companyData) {
             $company = new Company();
             $company->Name = $companyData[0];
             $company->Category = $companyData[1];
diff --git a/code/DevBuildGeneratorExtension.php b/code/DevBuildGeneratorExtension.php
new file mode 100644
index 0000000..9d5dada
--- /dev/null
+++ b/code/DevBuildGeneratorExtension.php
@@ -0,0 +1,14 @@
+<?php
+
+use SilverStripe\Core\Config\Configurable;
+use SilverStripe\ORM\DataExtension;
+
+/**
+ * There is no good place to put this setting, so it gets a class.
+ */
+class DevBuildGeneratorExtension extends DataExtension
+{
+    use Configurable;
+
+    private static $regenerate_on_build = false;
+}
diff --git a/code/Employee.php b/code/Employee.php
index 63509ea..72d9e5c 100644
--- a/code/Employee.php
+++ b/code/Employee.php
@@ -99,6 +99,10 @@ class Employee extends DataObject
     {
         parent::requireDefaultRecords();
         $employeeSet = DataObject::get(Employee::class);
+        if ($employeeSet->exists() && !static::config()->get('regenerate_on_build')) {
+            return;
+        }
+
         foreach ($employeeSet as $employee) {
             $employee->delete();
         }
diff --git a/code/TestRegistryDataObject.php b/code/TestRegistryDataObject.php
index 66bf931..f35777a 100644
--- a/code/TestRegistryDataObject.php
+++ b/code/TestRegistryDataObject.php
@@ -851,6 +851,10 @@ class TestRegistryDataObject extends DataObject implements RegistryDataInterface
 
         /** @var DataObject[] $all */
         $all = static::get();
+        if ($all->exists() && !static::config()->get('regenerate_on_build')) {
+            return;
+        }
+
         foreach ($all as $one) {
             $one->delete();
         }