By Aaron Kulindi

Traditionally, it has been a custom to build residential houses using bricks or blocks. When it comes to the level of walling
after the foundation has been set, the client may want to put up walls using brick work or block work. The choice of what to use essentially depends on the client’s needs and their financial standing, among other factors.

One of the advantages of blocks is that they form a stronger wall than bricks. A house built using blocks can have a last up to 100 years, while one built using bricks may last a shorter time. Another advantage blocks have over bricks is that during the manufacture of concrete blocks it’s much easier to estimate the number to be produced from a given amount of concrete.

On the other hand, it is much harder to estimate the number bricks, because during their manufacture, bricks lose moisture upon setting or when drying and in most cases, become smaller as a result. The impact is realised at the time of construction because normally, more mortar is used when laying the bricks than was initially planned for.

Building with blocks

If a client wants to build a house in a short time, blocks come in handy because of their size. One block is equivalent to four bricks, which reduces on the time spent on laying them. Despite all this, the majority of the people building 3-bedroom houses  prefer bricks to blocks due to the cost implications.

It is much more expensive to build a wall using blocks than it is using bricks. On average, one block costs about sh3,000, while one brick costs sh300. A standard block could take on the dimensions of 150x200x400mm and a brick could take on the dimensions of 100x100x200mm.

For a residential threebedroom house to be built on a 50x100 plot of land. This means that you should expect the walling  to take about 340 square metres for such a house. So, generally, you need about 48 bricks per square metre for brick walling and 12 blocks per square metre for block walling.

The total number of bricks required to finish the walling is about 16,320 while using blocks for the same house will be about 4,080.

From this comparison, a person building a tandard residential 3-bedroom house would spend about sh4.9m if they considered using bricks and approximately sh12.2m if they chose to use blocks, a difference of about sh7.3m.

The writer is a quantity surveyor