Herriott Services Ltd is a professional brickwork contractor covering Kent, South East London and Surrounding Areas

Brick Entrance Porches: Open, Enclosed, and Permitted Development Rules

22 February 2026 by Michael Swan 2 min read

A porch under 3m2 with a height under 3m often falls within permitted development. Here is what you can build without a planning application.

An entrance porch is one of the few external additions to a house that can often be built without planning permission. Under the 2015 GPDO, Schedule 2, Part 1, Class D, a porch is permitted development if it meets three criteria: the floor area does not exceed 3 square metres (measured externally), the height does not exceed 3 metres, and no part of the porch is within 2 metres of a boundary with a highway.

Open Porch Designs

An open porch uses low brick walls (typically 600mm high) or brick piers to support a roof canopy. The open sides keep the structure feeling light and welcoming. We often combine brick piers with an oak frame or green oak beam above, creating a feature that blends traditional materials with a contemporary feel. The brick piers need foundations appropriate for the soil type; on clay soils, even a small pier needs a foundation to at least 600mm.

Enclosed Porches

An enclosed porch adds a door and windows to create a buffer zone between the outside and the hallway. This is particularly useful in winter for shedding muddy boots and wet coats. The brickwork can match the main house, and the roof can be pitched, flat, or lean-to depending on the style of the property.

Brick and Timber Combinations

Curved brick walls flanking the entrance, combined with an oak or timber frame canopy, create a distinctive arrival point. See our article on curved brick walls for the technical detail on building curves.

View our bricklaying services or get in touch to discuss entrance feature ideas for your home.

Frequently Asked Questions

Under Approved Document Part L (2021, applicable in 2026), new build external walls must achieve a U-value of 0.26 W/m2K or better. Most specifications target 0.18 to 0.22 W/m2K.
Rigid PIR boards (Kingspan Kooltherm K106 or Celotex CW4000) are the most common full-fill cavity insulation. They offer the best thermal performance per millimetre of thickness (0.018 to 0.022 W/mK).
Mortar droppings on wall ties and insulation create thermal bridges, localised cold spots where heat escapes. They can also cause moisture transfer across the cavity, leading to damp patches on internal walls.
A thermal bridge is any point in the building envelope where heat can bypass the insulation. Common examples include mortar snots on wall ties, steel lintels without thermal breaks, and gaps in cavity insulation at junctions.
Aircrete blocks (Thermalite Shield or Celcon Standard at 100mm) with a thermal conductivity of 0.11 W/mK. Using denser blocks with higher conductivity would require thicker cavity insulation to achieve the same U-value.
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