diff --git a/src/Hydra/lib/Hydra/Controller/Build.pm b/src/Hydra/lib/Hydra/Controller/Build.pm
index 7b549d9b..6f20ac8a 100644
--- a/src/Hydra/lib/Hydra/Controller/Build.pm
+++ b/src/Hydra/lib/Hydra/Controller/Build.pm
@@ -30,6 +30,7 @@ sub view_build : Chained('build') PathPart('') Args(0) {
     $c->stash->{curTime} = time;
     $c->stash->{available} = isValidPath $build->outpath;
     $c->stash->{drvAvailable} = isValidPath $build->drvpath;
+    $c->stash->{flashMsg} = $c->flash->{afterRestart};
 
     if (!$build->finished && $build->schedulingInfo->busy) {
         my $logfile = $build->schedulingInfo->logfile;
@@ -155,4 +156,35 @@ sub nix : Chained('build') PathPart('nix') CaptureArgs(0) {
 }
 
 
+sub restart : Chained('build') PathPart('restart') Args(0) {
+    my ($self, $c) = @_;
+
+    my $build = $c->stash->{build};
+
+    requireProjectOwner($c, $build->project);
+
+    error($c, "This build cannot be restarted.")
+        unless $build->finished && $build->resultInfo->buildstatus == 3;
+
+    $c->model('DB')->schema->txn_do(sub {
+        $build->finished(0);
+        $build->timestamp(time());
+        $build->update;
+
+        $build->resultInfo->delete;
+
+        $c->model('DB::BuildSchedulingInfo')->create(
+            { id => $build->id
+            , priority => 0 # don't know the original priority anymore...
+            , busy => 0
+            , locker => ""
+            });
+    });
+
+    $c->flash->{afterRestart} = "Build has been restarted.";
+    
+    $c->response->redirect($c->uri_for($self->action_for("view_build"), $c->req->captures));
+}
+
+
 1;
diff --git a/src/Hydra/lib/Hydra/Controller/Root.pm b/src/Hydra/lib/Hydra/Controller/Root.pm
index 8da4b111..b4c331b8 100644
--- a/src/Hydra/lib/Hydra/Controller/Root.pm
+++ b/src/Hydra/lib/Hydra/Controller/Root.pm
@@ -82,13 +82,6 @@ sub logout :Local {
 }
 
 
-sub requireLogin {
-    my ($c) = @_;
-    $c->flash->{afterLogin} = $c->request->uri;
-    $c->response->redirect($c->uri_for('/login'));
-}
-
-
 sub queue :Local {
     my ($self, $c) = @_;
     $c->stash->{template} = 'queue.tt';
@@ -230,10 +223,7 @@ sub releases :Local {
 
     if (defined $subcommand && $subcommand ne "") {
 
-        return requireLogin($c) if !$c->user_exists;
-
-        error($c, "Only the project owner or the administrator can perform this operation.")
-            unless $c->check_user_roles('admin') || $c->user->username eq $project->owner->username;
+        requireProjectOwner($c, $project);
 
         if ($subcommand eq "edit") {
             $c->stash->{template} = 'edit-releaseset.tt';
@@ -272,10 +262,7 @@ sub create_releaseset :Local {
     die "Project $projectName doesn't exist." if !defined $project;
     $c->stash->{curProject} = $project;
 
-    return requireLogin($c) if !$c->user_exists;
-
-    error($c, "Only the project owner or the administrator can perform this operation.")
-        unless $c->check_user_roles('admin') || $c->user->username eq $project->owner->username;
+    requireProjectOwner($c, $project);
 
     if (defined $subcommand && $subcommand eq "submit") {
         my $releaseSetName = $c->request->params->{name};
@@ -468,10 +455,7 @@ sub project :Local {
 
     elsif ($subcommand ne "") {
 
-        return requireLogin($c) if !$c->user_exists;
-
-        error($c, "Only the project owner or the administrator can perform this operation.")
-            unless $c->check_user_roles('admin') || $c->user->username eq $project->owner->username;
+        requireProjectOwner($c, $project);
         
         if ($subcommand eq "edit") {
             $c->stash->{edit} = 1;
@@ -506,7 +490,7 @@ sub project :Local {
 sub createproject :Local {
     my ($self, $c, $subcommand) = @_;
 
-    return requireLogin($c) if !$c->user_exists;
+    requireLogin($c) if !$c->user_exists;
 
     error($c, "Only administrators can create projects.")
         unless $c->check_user_roles('admin');
diff --git a/src/Hydra/lib/Hydra/Helper/CatalystUtils.pm b/src/Hydra/lib/Hydra/Helper/CatalystUtils.pm
index 865666e6..58d9e81e 100644
--- a/src/Hydra/lib/Hydra/Helper/CatalystUtils.pm
+++ b/src/Hydra/lib/Hydra/Helper/CatalystUtils.pm
@@ -7,6 +7,7 @@ use Readonly;
 our @ISA = qw(Exporter);
 our @EXPORT = qw(
     getBuild error notFound
+    requireLogin requireProjectOwner
     $pathCompRE $relPathRE
 );
 
@@ -21,7 +22,7 @@ sub getBuild {
 sub error {
     my ($c, $msg) = @_;
     $c->error($msg);
-    $c->detach;
+    $c->detach; # doesn't return
 }
 
 
@@ -32,6 +33,24 @@ sub notFound {
 }
 
 
+sub requireLogin {
+    my ($c) = @_;
+    $c->flash->{afterLogin} = $c->request->uri;
+    $c->response->redirect($c->uri_for('/login'));
+    $c->detach; # doesn't return
+}
+
+
+sub requireProjectOwner {
+    my ($c, $project) = @_;
+    
+    requireLogin($c) if !$c->user_exists;
+    
+    error($c, "Only the project owner or the administrator can perform this operation.")
+        unless $c->check_user_roles('admin') || $c->user->username eq $project->owner->username;
+}
+
+
 # Security checking of filenames.
 Readonly::Scalar our $pathCompRE => "(?:[A-Za-z0-9-\+][A-Za-z0-9-\+\._]*)";
 Readonly::Scalar our $relPathRE  => "(?:$pathCompRE(?:\/$pathCompRE)*)";
diff --git a/src/Hydra/root/build.tt b/src/Hydra/root/build.tt
index 152a410c..4c1d639d 100644
--- a/src/Hydra/root/build.tt
+++ b/src/Hydra/root/build.tt
@@ -15,6 +15,11 @@
 </h1>
 
 
+[% IF flashMsg %]
+<p class="error">[% flashMsg %]</p>
+[% END %]
+
+
 <h2>Information</h2>
 
 <table class="layoutTable">
@@ -31,7 +36,7 @@
           <strong>Success</strong>
         [% ELSIF build.resultInfo.buildstatus == 1 %]
           <img src="/static/images/failure.gif" />
-          <span class="error">Build returned a non-zero exit code</span>
+          <span class="error">Build returned a non-zero exit code</span>          
         [% ELSIF build.resultInfo.buildstatus == 2 %]
           <img src="/static/images/failure.gif" />
           <span class="error">A dependency of the build failed</span>
@@ -39,6 +44,9 @@
           <img src="/static/images/failure.gif" />
           <span class="error">Build failed</span>
           (see <a href="#nix-error">below</a>)
+          <form action="[% c.uri_for('/build' build.id 'restart') %]" method="post" class="inline">
+            <button id="delete-project" type="submit">Restart</button>
+          </form>
         [% END %]
       [% ELSIF build.schedulingInfo.busy %]
         <strong>Build in progress</strong>
diff --git a/src/Hydra/root/static/css/hydra.css b/src/Hydra/root/static/css/hydra.css
index 672a4bad..efd5b046 100644
--- a/src/Hydra/root/static/css/hydra.css
+++ b/src/Hydra/root/static/css/hydra.css
@@ -436,4 +436,8 @@ select {
 
 button {
     background-color: #f0f0e0;
-}
\ No newline at end of file
+}
+
+form.inline {
+    display: inline;
+}