Last edited 13 Mar 2018

How to build a porch


A porch is a covered single-storey attachment that projects out of a house or building. It is a particularly popular option for extending a domestic building, typically at the front entrance, and it can be relatively inexpensive to construct. The structure of the porch is external to the building walls but it can be enclosed in types of frames, such as walls, columns, screens, and so on.

Generally, a porch consists simply of brick dwarf walls, columns, windows and a door. It will require proper foundations as appropriate and the junctions between the walls of the porch and those of the existing building will need to be properly waterproofed at roof level and the sides.

Internally, they can be left as open brick or plastered and painted. They will often have a light fitting and an electric socket.

Due to their relatively small size, a porch may not require planning permission (although they may in a conservation area or for a listed building). Building regulations approval may be required if the porch is not separated from the house by an internal door and is heated, or if there are structural, accessibility or drainage implications. Generally, as long as it covers less than 3 sq. m and is less than 2 m distance from a boundary with a highway (including footpaths), the porch will not require planning permission.

However, if the porch is to contain a fuel store, a toilet, or enclose any ventilation connecting the building interior to the exterior, then planning permission will need to be granted.

There are several different types of porch and it depends to a considerable extent on the existing front entrance as to which is the most suitable. For example, a plain front (as is common with terraced houses) will typically only be suitable for a mounted canopy above the door; a recessed front door (as is common with Victorian and Edwardian houses) will require the recess being blocked in with brickwork and/or glass. Buildings with existing canopies may be capable of being infilled with timber, brick and/or glass, although care should be taken to install a damp-proof course (DPC).

When choosing or designing a porch it is important to make sure that it conforms with the existing building (i.e. use of the same materials) as it could have a negative visual impact if it does not. An option that can help to ensure harmonisation is to move the existing front door to the exterior face of the porch, with a new door installed between the building and the porch. Porches will often incorporate a large amount of glazing in order to maximise natural light, and so the window design should complement those of the rest of the building or, at least, the frontage.

In terms of budgeting the building of a porch, some of the important factors to consider include:

  • Whether it will be fully enclosed or not.
  • Whether it will be partially or fully glazed on all sides.
  • The type of roof – flat or sloping.
  • The type of cladding or external brickwork to be used.

Some of the advantages of building a porch extension include:

  • Can provide a beneficial visual aesthetic to the front of a building.
  • It can help reduce heat loss from the building and improve energy efficiency.
  • Can create useful storage space for coats and shoes, or a place to decorate with ornaments.

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