The foundations are the most important part of a property. Without them the building could be unstable and dangerous. Whether you are designing a new build or are making changes to a structure, you need to think about what type of foundation you need. As one of the top providers of residential architecture London has, we know how vital this is. We also know how tricky it can be because the land can differ dramatically. We are happy to offer advice.

Identify the type of ground

There are many different types of ground you may encounter. You need to know what they are to ensure your foundations are right.

Rock

Naturally rocky ground is the best option. It has a much higher load bearing capacity so you may not need really deep foundations. However, you may need to level it off and you must think about drainage.

Chalk

It is a little harder to work with chalky ground than solid rock. Here you need to think about how firm the chalk is; you get more stability when it is firm and will need to excavate past soft materials. You need to ensure your foundations go below the frost line to account for heave. It is also important to look for any hollows or caves.

Gravel or sand

If the ground is gravel, or a mix of it plus sand, you need to ensure it has suitable load bearing capacity. This will be lower if the materials are not properly compacted. It will also be much less if it is an area with a high water table. In some cases you may need sheet piling to help retain the ground when you dig foundation trenches.

Clay

It can be very tricky to deal with clay soils because the moisture content can vary greatly. What this means is you can expect quite a lot of movement due to expansion and shrinkage. To account for this you will likely need deeper foundations until you reach clay where the moisture content is consistent. It may be necessary to excavate up to 3 metres. You may even need to line the bottom of trenches to protect from heave.

Peat

This is one of the only types of ground that is harder to work with than clay. Peat and very wet sandy soil are terrible subsoils. You will likely need to strip back until you can find a layer that has more load bearing capacity. If this is not possible, you will need raft foundation with extra reinforcement.

Has there been previous excavation and filling?

You need to take extra precautions if there has been any prior excavation or filling on the site. This kind of work will mean the ground is not as compact as it should be, compromising the load bearing capacity. What you will most likely need to do is excavate past this to find a compact layer.

Slopes

On sloping sites you need a very specific type of foundations, regardless of the type of ground. What you have to build is a stepped foundation that will provide the right kind of stability.

Designing residential architecture in London

At Coffey Architects we know how challenging it can be at times to deal with different kinds of ground. In fact, London can be a very tricky destination. The land can differ greatly here, from chalky to clay and gravel. There are also plenty of spots with wetter ground because of the Thames and its tributaries. Luckily, we can offer solutions for most locations.

So, if you are thinking about residential architecture, London clients can rely on us. We will give you the very best support to ensure you get exactly what you are looking for. Get in touch today and let us know where you are with the project.