diff --git a/app/models/spree/product_decorator.rb b/app/models/spree/product_decorator.rb
index 352e5bf8cc..4a3e5bac81 100644
--- a/app/models/spree/product_decorator.rb
+++ b/app/models/spree/product_decorator.rb
@@ -10,6 +10,12 @@ Spree::Product.class_eval do
 
   validates_presence_of :supplier
 
+  validates_presence_of :variant_unit, if: :has_variants?
+  validates_presence_of :variant_unit_scale,
+                        if: -> p { %w(weight volume).include? p.variant_unit }
+  validates_presence_of :variant_unit_name,
+                        if: -> p { p.variant_unit == 'items' }
+
   after_initialize :set_available_on_to_now, :if => :new_record?
 
 
diff --git a/app/models/spree/variant_decorator.rb b/app/models/spree/variant_decorator.rb
new file mode 100644
index 0000000000..10fe4234db
--- /dev/null
+++ b/app/models/spree/variant_decorator.rb
@@ -0,0 +1,7 @@
+Spree::Variant.class_eval do
+  validates_presence_of :unit_value,
+                        if: -> v { %w(weight volume).include? v.product.variant_unit }
+
+  validates_presence_of :unit_description,
+                        if: -> v { v.product.variant_unit.present? && v.unit_value.nil? }
+end
diff --git a/db/migrate/20131128034556_setup_product_units_and_values.rb b/db/migrate/20131128034556_setup_product_units_and_values.rb
new file mode 100644
index 0000000000..d6cf779aed
--- /dev/null
+++ b/db/migrate/20131128034556_setup_product_units_and_values.rb
@@ -0,0 +1,14 @@
+class SetupProductUnitsAndValues < ActiveRecord::Migration
+  def change
+    change_table :spree_products do |t|
+      t.string :variant_unit
+      t.float :variant_unit_scale
+      t.string :variant_unit_name
+    end
+
+    change_table :spree_variants do |t|
+      t.float :unit_value
+      t.string :unit_description
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index a95c7c04b5..5265be891e 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20131030031125) do
+ActiveRecord::Schema.define(:version => 20131128034556) do
 
   create_table "adjustment_metadata", :force => true do |t|
     t.integer "adjustment_id"
@@ -481,9 +481,9 @@ ActiveRecord::Schema.define(:version => 20131030031125) do
     t.string   "email"
     t.text     "special_instructions"
     t.integer  "distributor_id"
-    t.integer  "order_cycle_id"
     t.string   "currency"
     t.string   "last_ip_address"
+    t.integer  "order_cycle_id"
     t.integer  "cart_id"
   end
 
@@ -611,6 +611,9 @@ ActiveRecord::Schema.define(:version => 20131030031125) do
     t.boolean  "group_buy"
     t.float    "group_buy_unit_size"
     t.boolean  "on_demand",            :default => false
+    t.string   "variant_unit"
+    t.float    "variant_unit_scale"
+    t.string   "variant_unit_name"
   end
 
   add_index "spree_products", ["available_on"], :name => "index_products_on_available_on"
@@ -872,20 +875,22 @@ ActiveRecord::Schema.define(:version => 20131030031125) do
   add_index "spree_users", ["persistence_token"], :name => "index_users_on_persistence_token"
 
   create_table "spree_variants", :force => true do |t|
-    t.string   "sku",                                         :default => "",    :null => false
-    t.decimal  "weight",        :precision => 8, :scale => 2
-    t.decimal  "height",        :precision => 8, :scale => 2
-    t.decimal  "width",         :precision => 8, :scale => 2
-    t.decimal  "depth",         :precision => 8, :scale => 2
+    t.string   "sku",                                            :default => "",    :null => false
+    t.decimal  "weight",           :precision => 8, :scale => 2
+    t.decimal  "height",           :precision => 8, :scale => 2
+    t.decimal  "width",            :precision => 8, :scale => 2
+    t.decimal  "depth",            :precision => 8, :scale => 2
     t.datetime "deleted_at"
-    t.boolean  "is_master",                                   :default => false
+    t.boolean  "is_master",                                      :default => false
     t.integer  "product_id"
-    t.integer  "count_on_hand",                               :default => 0
-    t.decimal  "cost_price",    :precision => 8, :scale => 2
+    t.integer  "count_on_hand",                                  :default => 0
+    t.decimal  "cost_price",       :precision => 8, :scale => 2
     t.integer  "position"
-    t.integer  "lock_version",                                :default => 0
-    t.boolean  "on_demand",                                   :default => false
+    t.integer  "lock_version",                                   :default => 0
+    t.boolean  "on_demand",                                      :default => false
     t.string   "cost_currency"
+    t.float    "unit_value"
+    t.string   "unit_description"
   end
 
   add_index "spree_variants", ["product_id"], :name => "index_variants_on_product_id"
diff --git a/spec/factories.rb b/spec/factories.rb
index 3791cd4143..f036156402 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -153,6 +153,15 @@ FactoryGirl.modify do
 
     supplier { Enterprise.is_primary_producer.first || FactoryGirl.create(:supplier_enterprise) }
     on_hand 3
+
+    variant_unit 'weight'
+    variant_unit_scale 1
+    variant_unit_name ''
+  end
+
+  factory :base_variant do
+    unit_value 1
+    unit_description ''
   end
 
   factory :shipping_method do
diff --git a/spec/models/spree/product_spec.rb b/spec/models/spree/product_spec.rb
index 7d4459b3b7..7fe3c4219a 100644
--- a/spec/models/spree/product_spec.rb
+++ b/spec/models/spree/product_spec.rb
@@ -14,7 +14,7 @@ module Spree
       end
 
       it "requires a supplier" do
-        product = create(:product)
+        product = create(:simple_product)
         product.supplier = nil
         product.should_not be_valid
       end
@@ -24,6 +24,73 @@ module Spree
         product = Product.new
         product.available_on.should == Time.now
       end
+
+      context "when the product has variants" do
+        let(:product) do
+          product = create(:simple_product)
+          create(:variant, product: product)
+          product
+        end
+
+        it "requires a unit" do
+          product.variant_unit = nil
+          product.should_not be_valid
+        end
+
+        %w(weight volume).each do |unit|
+          context "when unit is #{unit}" do
+            it "is valid when unit scale is set and unit name is not" do
+              product.variant_unit = unit
+              product.variant_unit_scale = 1
+              product.variant_unit_name = nil
+              product.should be_valid
+            end
+
+            it "is invalid when unit scale is not set" do
+              product.variant_unit = unit
+              product.variant_unit_scale = nil
+              product.variant_unit_name = nil
+              product.should_not be_valid
+            end
+          end
+        end
+
+        context "when the unit is items" do
+          it "is valid when unit name is set and unit scale is not" do
+            product.variant_unit = 'items'
+            product.variant_unit_name = 'loaf'
+            product.variant_unit_scale = nil
+            product.should be_valid
+          end
+
+          it "is invalid when unit name is not set" do
+            product.variant_unit = 'items'
+            product.variant_unit_name = nil
+            product.variant_unit_scale = nil
+            product.should_not be_valid
+          end
+        end
+      end
+
+      context "when product does not have variants" do
+        let(:product) { create(:simple_product) }
+
+        it "does not require any variant unit fields" do
+          product.variant_unit = nil
+          product.variant_unit_name = nil
+          product.variant_unit_scale = nil
+
+          product.should be_valid
+        end
+
+        it "requires a unit scale when variant unit is weight" do
+          product.variant_unit = 'weight'
+          product.variant_unit_scale = nil
+          product.variant_unit_name = nil
+
+          product.should_not be_valid
+        end
+      end
     end
     
 
diff --git a/spec/models/spree/variant_spec.rb b/spec/models/spree/variant_spec.rb
new file mode 100644
index 0000000000..0baf0b53bc
--- /dev/null
+++ b/spec/models/spree/variant_spec.rb
@@ -0,0 +1,64 @@
+require 'spec_helper'
+
+module Spree
+  describe Variant do
+    context "when the product has variants" do
+      let!(:product) { create(:simple_product) }
+      let!(:variant) { create(:variant, product: product) }
+
+      %w(weight volume).each do |unit|
+        context "when the product's unit is #{unit}" do
+          before do
+            product.update_attribute :variant_unit, unit
+          end
+
+          it "is valid when unit value is set and unit description is not" do
+            variant.unit_value = 1
+            variant.unit_description = nil
+            variant.should be_valid
+          end
+
+          it "is invalid when unit value is not set" do
+            variant.unit_value = nil
+            variant.should_not be_valid
+          end
+        end
+      end
+
+      context "when the product's unit is items" do
+        before do
+          product.update_attribute :variant_unit, 'items'
+        end
+
+        it "is valid with only unit value set" do
+          variant.unit_value = 1
+          variant.unit_description = nil
+          variant.should be_valid
+        end
+
+        it "is valid with only unit description set" do
+          variant.unit_value = nil
+          variant.unit_description = 'Medium'
+          variant.should be_valid
+        end
+
+        it "is invalid when neither unit value nor unit description are set" do
+          variant.unit_value = nil
+          variant.unit_description = nil
+          variant.should_not be_valid
+        end
+      end
+    end
+
+    context "when the product does not have variants" do
+      let(:product) { create(:simple_product, variant_unit: nil) }
+      let(:variant) { product.master }
+
+      it "does not require unit value or unit description when the product's unit is empty" do
+        variant.unit_value = nil
+        variant.unit_description = nil
+        variant.should be_valid
+      end
+    end
+  end
+end