How Much Does Subsidence Devalue a Property?

Subsidence is something house owners never want to face. Yet, recent data has shown that more homes are at an increased risk of subsidence due to hotter and drier summers. 

But, what is subsidence, how much does subsidence devalue a property exactly, how can you recognise it, and how much does it cost to repair it? 

Let’s find out. 

What Does Subsidence Mean?

Subsidence is the sinking or settling of the ground’s surface. 

This process pulls the foundations of the property down and can cause floors and walls to shift, which can lead to cracks and potentially destabilise the construction. 

How much does subsidence devalue a property?

Subsidence in a house can significantly decrease the value of a property. The amount of devaluation depends on a number of factors, including the extent of the damage (security level) and the location of the property (some areas are at a higher risk of subsidence).

In some cases, subsidence can decrease the market value of a property by as much as 20%. In extreme cases, subsidence can cause severe structural problems and render the property inhabitable. If that happens, the property will likely have to be demolished. 

If you want to learn how much your property is worth and whether subsidence has decreased its value, you’ll have to talk to an estate agent and ask them to evaluate the property.

What Are the Signs of Subsidence in a House?

The earliest and most common house subsidence signs are cracks in foundations, walls, floors, and ceilings, which widen over time.

Other signs of subsidence in a house include:

• Sinking or settling of the ground around your home.
• Ripped wallpaper.
• Doors and windows that no longer close or open properly.
• Gaps between masonry.
• Tilting or disintegration of brickwork.
• Uneven flooring.
•  Water seeping through the cracks in the foundation.

If you notice any of these subsidence signs, it is important to have your home inspected by a chartered surveyor as soon as possible. Subsidence can progress quickly and cause significant damage to your home if left unchecked.

What are the causes of subsidence? 

Subsidence can happen for a variety of reasons, but some of the most common are:

• Tree roots

Tree roots are certainly one of the most prevalent, and if not the most common, causes of subsidence. A big tree near your property can lead the ground to lose moisture and shrink.

• Clay soil

Soil with a high clay content can dry out faster, especially during long, hot summers. When the volume of the soil decreases, it can cause the building’s foundation to subside and trigger ground movement.

• Man-made issues

Issues such as damaged drains, vibrations from traffic, mining history, poorly built ground, or foundations can lead to subsidence over time. Leaks from plumbing or sewer lines can also wash away the soil underneath your home, causing it to settle.

• Weather/climate

Soil contracts in the dry and expands in the wet. Long periods of dry summer and wet winter weather cause constant fluctuations in groundwater and make the soil unstable. 

How Much Does It Cost to Repair Subsidence? 

(HomeProtect)

The cost of repairing subsidence depends on the extent of the damage, the size of the subsided house, and the location of the affected property. 

House subsidence repairs are typically expensive and often take months to complete. The cost to fix subsidence in the UK ranges anywhere between £5,000 and £50,000. 

If you have insurance, especially home insurance, that covers subsidence, it can cover some of the full cost.

Subsidence repair cost

The cost of repairing subsidence mainly depends on the type of repairs that the property requires to fix the issue. These can include:

• Underpinning: Underpinning is a process of excavating around the existing foundations and installing new, stronger foundations to prevent or reduce subsidence.

• Mass concrete method: This method involves installing a layer of mass concrete over the existing foundations. 

• Piling: Piling is a technique where you drive long, sturdy posts into the ground until they reach a depth where the soil is more stable. It is often used to provide support for structures built on soft or unstable ground.

• Injecting: Injecting a material into the soil can help restore the ability of the soil to support the weight of the structure. There are several different types of materials that can be injected, including grout, concrete, and even water. The injection of the material is typically done with a pump.

• Beam and base method: The beam and base method involves excavating around the perimeter of the foundation and installing steel beams and concrete footings. 

Here’s how much they cost.

(Checkatrade)

Subsidence repair costs	Cost + VAT ( low – high)	Average cost
Underpinning	£10,000 – £15,000	£12,500
Underpinning cost per m (up to 1m)	£1,000 – £1,750	£1,500
Mass concrete method (per m)	£250 – £500	£375
Piling	£750 – £1,500	£1,250 per m2
Injector method	£400 – £700	£550 per m2
Beam and base method	£500 – £900	£700 per m2
Structural engineer hourly rate	£50 – £90	£70
Survey	£400 – £1,500	£950
Party Wall Agreement	£1,500 – £3,500	£2,500

Unfortunately, the costs associated with fixing property subsidence don’t stop there. The property might require additional work, such as: 

• Replacing bricks
• Repointing brickwork
• Rendering external walls
• Windows replacement
• Internal plastering and decorating
• Plumbing repair

How to Sell a House With Subsidence

Selling a house with subsidence can put off some buyers but it’s not a deal-breaker for everyone.

If you want to see the house without having to repair the damage caused by the subsidence (and the subsidence itself), you’ll likely need to sell the house for a much lower price since the buyer will have to undertake the work and cover the costs for the repair. 

The best way to go about it is to have your property evaluated by a professional. They’ll give you an estimated price based on the location, the size of the property, and the extent of the damage. 

This will help you to set a realistic asking price and give you an idea of how much work needs to be done to fix the problem.

What’s better: selling quickly or treating subsidence?

The decision whether to sell property with subsidence or treat subsidence mainly depends on personal circumstances. 

Selling quickly has obvious advantages. It can help you avoid further financial losses and the long and expensive subsidence repairs. However, the property will sell for less than its market value, and the seller may have difficulty finding a buyer who’s willing to accept the risk of subsidence.

On the other hand, treating a subsidence house is pricey and there’s no guarantee that a subsiding house that has undergone repairs, wouldn’t face the same issue in the future. 

However, it will add significant value to the property and if your property is insured, your provider will cover most of the costs related to the repairs.

Bottom Line

House subsiding can be caused by various factors, such as poor construction, water damage, and tree roots near the property. Depending on the extent of the damage and the location, you still might be able to sell the property. However, subsidence can significantly decrease the value of a property and in some cases, you might even have to sell it for 20% less than its market value.