diff --git a/stack_orchestrator/build/build_webapp.py b/stack_orchestrator/build/build_webapp.py
index 1021f4bf..29991e0e 100644
--- a/stack_orchestrator/build/build_webapp.py
+++ b/stack_orchestrator/build/build_webapp.py
@@ -30,6 +30,12 @@ from stack_orchestrator.build import build_containers
 from stack_orchestrator.deploy.webapp.util import determine_base_container, TimedLogger
 from stack_orchestrator.build.build_types import BuildContext
 
+def create_env_file(env_vars, repo_root):
+    env_file_path = os.path.join(repo_root, '.env')
+    with open(env_file_path, 'w') as env_file:
+        for key, value in env_vars.items():
+            env_file.write(f"{key}={value}\n")
+    return env_file_path
 
 @click.command()
 @click.option('--base-container')
@@ -37,8 +43,9 @@ from stack_orchestrator.build.build_types import BuildContext
 @click.option("--force-rebuild", is_flag=True, default=False, help="Override dependency checking -- always rebuild")
 @click.option("--extra-build-args", help="Supply extra arguments to build")
 @click.option("--tag", help="Container tag (default: cerc/<app_name>:local)")
+@click.option("--env", help="Environment variables for webapp (format: KEY1=VALUE1,KEY2=VALUE2)", default="")
 @click.pass_context
-def command(ctx, base_container, source_repo, force_rebuild, extra_build_args, tag):
+def command(ctx, base_container, source_repo, force_rebuild, extra_build_args, tag, env):
     '''build the specified webapp container'''
     logger = TimedLogger()
 
@@ -88,9 +95,28 @@ def command(ctx, base_container, source_repo, force_rebuild, extra_build_args, t
     # Now build the target webapp.  We use the same build script, but with a different Dockerfile and work dir.
     container_build_env["CERC_WEBAPP_BUILD_RUNNING"] = "true"
     container_build_env["CERC_CONTAINER_BUILD_WORK_DIR"] = os.path.abspath(source_repo)
-    container_build_env["CERC_CONTAINER_BUILD_DOCKERFILE"] = os.path.join(container_build_dir,
-                                                                          base_container.replace("/", "-"),
-                                                                          "Dockerfile.webapp")
+
+    # Check if Dockerfile exists in the repository
+    repo_dockerfile = os.path.join(container_build_env["CERC_CONTAINER_BUILD_WORK_DIR"], "Dockerfile")
+    default_dockerfile = os.path.join(container_build_dir,
+                                    base_container.replace("/", "-"),
+                                    "Dockerfile.webapp")
+
+    if os.path.isfile(repo_dockerfile):
+        env_vars = {}
+        if env:
+            for pair in env.split(','):
+                key, value = pair.split('=')
+                env_vars[key.strip()] = value.strip()
+        
+        container_build_env["CERC_CONTAINER_BUILD_DOCKERFILE"] = repo_dockerfile
+        
+        # Create .env file with environment variables
+        env_file_path = create_env_file(env_vars, container_build_env["CERC_CONTAINER_BUILD_WORK_DIR"])
+        container_build_env["CERC_CONTAINER_BUILD_ENV_FILE"] = env_file_path
+    else:
+        container_build_env["CERC_CONTAINER_BUILD_DOCKERFILE"] = default_dockerfile
+
     if not tag:
         webapp_name = os.path.abspath(source_repo).split(os.path.sep)[-1]
         tag = f"cerc/{webapp_name}:local"