If you are currently building a house in the UK, you will need to install the right windows for your home. When you are on the lookout for several window types, why not choose double glazed sash windows? However, you should choose a window installation provider that follows the guidelines on window replacement in the UK. A business that is registered at FENSA or Fenestration Self-Assessment Scheme assures you that they follow strict building codes. These companies on window replacement also aim at safeguarding the environment since environment protection is among the concerns of FENSA. When intending to put up windows, you need to go for a company that is registered at FENSA.