How to choose the right brick for your extension

Of all the materials you'll choose for an extension, the brick is the one you'll look at most. Get it right and the new work disappears into the old; get it wrong and it sits awkwardly for the next century.

The first decision is type. Engineering bricks are dense, strong and frost-resistant — perfect for plinths and retaining walls but visually utilitarian. Facing bricks are what you'll see on most British homes — clay, stock or wirecut, in a huge range of colours. Handmade bricks have the soft, irregular face that gives heritage extensions their character.

Next, size. The standard UK brick is 215 × 102.5 × 65mm. Older homes were built with slightly thicker bricks and wider joints, so a modern brick laid to modern coursing will never quite match — your bricklayer will need to adjust the bed-joint to bring courses level with the existing wall.

Colour and texture are the longest decisions and the most important. Order at least three sample packs, stack a small panel on site, look at them in the rain and the sun. A brick that looks perfect under shop lights can look entirely wrong against the actual wall it's joining.

Finally, mortar. Two extensions can be built from identical bricks and look completely different because of the mortar joint. Lighter mortars open the wall up; darker mortars sink it back. Always insist on a small sample panel before the order is placed.