Foundations in London (225)

When building a house, it’s essential to use the right type of foundation. The soil and ground conditions need to be factored in as well as the size and type of structure. In fact, there are a few different building foundation types, including:

Shallow foundations

These building foundations are used to support smaller buildings with a low load. Common types of shallow foundations include:

• Strip foundations: Perfect for load bearing walls, strip foundations are well suited to new conservatories.

• Raft foundations: Made up of a large slab, raft foundations cover the entire base of a building.

• Pad foundations: Used to support localised loads, pad foundations are often positioned under columns.

Deep foundations

Generally deep building foundations are used when the ground is not strong enough to support larger loads. Common deep building foundations types include:

• Pile foundations: These deep foundations are built using steel columns that are set under a building to add extra support.

Caissons: Caissons are made by drilling a column into the ground. This hole is then filled with concrete and reinforced steel.

Before picking a type of house foundation, it’s important to look at the soil covering the area. There are a few different types of soil, each with its own properties.

When building foundations, your tradesperson will look at your subsoil before beginning. The categories of soil are:

• Clay

• Gravel and sand

• Chalk

• Rock

• Peat

• Firm clay over soft clay

• Filled ground

If you’re planning to build a new house or structure, picking the right building foundations is one of the most important steps. So, what house foundation is best? Well, this really comes down to the type of soil and ground conditions, the size and weight of the building and access to the site.

It’s the job of your tradesperson, structural engineer and architect to decide on which house foundation is best for your project. This will also be approved by a building inspector before you can start construction.

For example, if you’re adding a small annex to your property, this isn't too heavy a load so using shallow foundations is a great option. Whereas building a large three storey house will require deeper foundations.

The stability and durability of your home depends strongly on the strength of its foundations. Unless you are a DIY expert, we’d recommend leaving foundations to the professionals. That way you can feel safe in your new home and prevent any future issues.

Wondering how to construct building foundations? Below is a summary of the process:

1. Preparation: Making sure the ground is ready to support your foundations by removing any plants, stones and trees

2. Marking: Measuring the area your foundations will cover and marking the lines it will follow

3. Excavation: Digging into the ground where your foundations will sit

4. Sub base: Adding and compacting your sub base

5. Formwork: Adding formwork to keep the concrete in place while it sets

6. Concrete: Pouring the concrete into the form you created

7. Levelling: Levelling and tamping down the newly poured concrete before it sets

8. Curing: Covering the concrete with a tarp and allowing it to cure

If you have plans to build any kind of structure on your property, you’ll know that adding foundations can be labour intensive. So, how much do building foundations cost? This really depends on the type of foundation you’re using as well as the size of the foundations.

As a rough guide, the average house foundation cost for strip foundations is £110 per square metre. If you want to know more about foundation cost per square foot, check out our new home foundation cost guide. There you can also find advice and tips for choosing foundations, different building foundation types and important considerations.

How much do foundation repairs cost?

Over time foundations may need to be repaired to keep your home stable and secure. It’s vital you get your house foundations repaired sooner rather than later before your home becomes damaged.

If you’re curious how much foundation repairs cost, read our handy guide. For reference, the average cost to repair foundations is £8,500.

Want to speak to foundation builders in London?

If you’re planning a construction project, you’ll want to find an experienced, qualified professional to take on your project. Using our online search feature is one of the best ways to find a foundation builder you can depend on. Just type in your postcode to find a variety of experts in your area.

Another option is to try our request a quote feature. Send us all the details of your project and we’ll forward these to three recommended foundations builders in London. You’ll then receive three quotes, it really is that simple.