Add backend for property account details

app/models/measurement.rb

@@ -0,0 +1,20 @@
+class Measurement
+  include ActiveModel::Validations
+
+  attr_reader :value, :unit
+
+  VALID_UNITS = %w[sqft sqm]
+
+  validates :unit, inclusion: { in: VALID_UNITS }
+  validates :value, presence: true
+
+  def initialize(value, unit)
+    @value = value.to_f
+    @unit = unit.to_s.downcase.strip
+    validate!
+  end
+
+  def to_s
+    "#{@value.to_i} #{@unit}"
+  end
+end