Alternative structural systems

Want to step away from the mainstream? Anamika Talwaria lays out some of the less common construction methods and how they could suit your home building project

Anamika Talwaria looks at the lesser-used build routes you could use to construct your bespoke abode

Araft of construction options is available to self builders, with conventional systems ranging from cavity wall masonry to timber frame, oak and more – all of which offer plenty of benefits. But if you have specific goals for your build, it might be time to look at some of the alternatives.

A big driver for people wanting to create a bespoke abode is green construction, so it makes sense that many up-and-coming systems are promoted for their excellent eco credentials. For example, cob is a sustainable, zero waste method relying on local materials and labour.

Other motivations include speed of construction and wow factor designs. Systems such as steel frame and cross-laminated timber (CLT), are newer innovations which can offer fantastic features and are prefabricated offsite.

No matter your priorities, the alternatives have heaps of character on offer – but all are yet to enter the mainstream. So, here are some key facts to know about these lesserused construction systems so you can make an informed decision about the make-up of your forever home.

Perhaps the alternative with the longest history – dating back to 8,000BC – many houses in the south west of England are earth buildings constructed with cob. People love the heritage aesthetic of this material and homes built this way feel cosy and warm. Plus, new initiatives, like the Cobbauge project, are looking into ways to modernise this technique so that it can be used more widely.

The benefits

Cob walling is made by combining water, soil (often sourced on site) and straw or other natural fibres, so carries a tiny carbon footprint

The walls will have high thermal mass, creating a comfortable and energy efficient internal climate all year round (see page 92 for more)

Cob is usually combined with other sustainable, nontoxic materials such as clay or lime plaster, creating a healthy internal environment

Mud building makes for an easy DIY self build, cutting both labour and material costs

The limitations

Homes are limited to two storeys, as anything taller ends up with very thick walls (as with straw bale)

The finished walling needs frequent maintenance, including an annual lime wash

Each cob course needs to fully dry before you can lay the next, so bad weather will limit how fast you can build Building Regs will need ample documentation, especially in relation to thermal mass and the passage of moisture