Update 2022: Home improvement and construction firms in the UK are reporting unprecedented price increases due to a number of factors. This has been widely reported in the media and confirmed by our own research. The prices on this page were updated in 2022 but we urge consumers to use a price comparison service such as Bark as they will be able to provide up to date quotes for complex projects such as house underpinning.

In 2022 we got in touch with several underpinning experts from various locations around the UK and asked them how much it costs to underpin a house. The responses varied from the suspiciously affordable to eye-watering expensive and the advice we received was just as inconsistent.

In a hurry?

In the table below, you’ll see the average price for house underpinning, based on the prices we were given by the respondents:

The prices above include VAT and are per linear metre for our property. Your project may require deeper and wider underpinning which would increase the price considerably.

The Three Different Types of Underpinning

Those sourcing prices for house underpinning are likely to be given quotes or estimates for one of three different methods:

Mass Concrete Pour

This is a time-tested, classic method of underpinning and is the most popular option. Holes around one metre wide and to a depth decided by an engineer are dug under the walls, these are shuttered with boarding and concrete is then filled into the void. The underpinning is completed in one-metre sections so the property above is always supported. Mass concrete pour is generally the best option when the foundations don’t need to go too deep, if the ground conditions require a very deep concrete pour, another option should be considered.

Expect to pay around £1750 per linear metre of wall for a standard underpinning project.

The Beam Method

Instead of digging out one-metre sections under the entire length of the wall and filling them with concrete, one could create fewer concrete sections and bridge them with a beam that would support the wall above. This is the Beam Method and is more suited to situations where the foundations need to go deeper.

Expect to pay around £2000 per linear metre of wall.

Piling

Piling is where pipes are driven deep into the ground, often more than five metres, these are then used to support the new foundation which underpins the wall. Piling is usually done in areas where the soil is poor and there’s very little natural support for the weight of the property.

Expect to pay around £2000 – £2500 per linear metre depending in the depth of the pile and the complexity of the project.

Extra Underpinning Costs to Consider

The prices on this page include the materials and labour for house underpinning but they exclude:

Party Wall Agreements

If you live in a semi-detached or terraced home, you’ll need to serve two months’ written notice to your neighbours, you should also inform them of their rights under the Party Wall Act.

If your neighbour consents to the work on your home, you can proceed.

If they don’t consent or fail to respond, you’ll need to start the party wall agreement process, this involves arranging for a surveyor to inspect the boundary wall and draw up a legal document detailing the condition of the wall. This can cost between £500 and £1500 per neighbour but protects the party from malicious claims

Structural Engineer Costs

Exactly how deep and wide the foundations must go should be calculated by a structural engineer. Their prices vary but for a typical house underpinning project, expect to pay a few hundred pounds.

Building Control Notification

You’ll need to notify your local building control office prior to the work commencing, there is a fee for this and it varies from council to council.

Unexpected Work

It’s not unusual for underpinning projects to go over budget and this is almost always due to the soil conditions discovered after the excavation has begun. If the foundations need to go deeper, the project will take longer, may require heavier machinery and more concrete or other materials. Allow for a contingency of 10% and you shouldn’t go too far wrong.

Do You Really Need Underpinning?

Vertical movement is quite normal and is seen in many homes, especially those that are older and were built on shallower foundations, it’s called settling and is quite different to subsidence.

In fact, underpinning can cause more problems if only one wall is underpinned and supported while the rest of the property is left on the existing foundations and continues to settle.

Conservatories are a classic example of how one structure can settle at a different rate to another as they are lighter than the house they are attached to, so they don’t settle as deep or as quickly as the heavier house. This can lead to cracks in the walls where the conservatory meets the main house. This type of movement is perfectly normal and is just a case of both structures settling naturally in the soil, just at a different rate. The same issue can apply to extensions and bay windows.

Many cases of subsidence are in fact settling and nothing to worry about. The question is whether the movement is historical or recent and whether it will continue or has stopped.

Only a structural engineer will be able to advise further.

Examples of When You’ll Need Underpinning

Here are a few examples of when you may need underpinning:

• Poor quality construction.
• Loft extension (esp on older homes built on shallow foundations).
• Basement extensions.
• Flooding or damage from burst pipes etc.
• Ground heave from tree roots etc.

Subsidence Warning Signs

There are several warning signs of subsidence to look out for:

• Doors and windows not fully closing and needing adjustments from time to time.
• Cracks and splits in the external or internal wall, although some of these might be historical “settling” and nothing to be concerned about.
• Cracks appearing after recent wallpapering or decorating are a telltale sign of movement that might otherwise not be detected.
• Neighbouring homes needing remedial work to the foundations.
• Walls bowing inwards or outwards.
• Uneven floors.
• Gaps, often uneven, between the floor covering and the skirting boards.

Underpinning Websites We Think Are Worth a Visit

We are not associated with any of the sites listed below but feel they have some great information and/or photos of underpinning work so you can get an idea of how extensive a project like is and the importance of using a trusted and reliable tradesperson.

This Dail Mail article contains a horror story about a couple losing everything after their home collapsed during underpinning work, even though they carried out due diligence and checked the builder’s history and insurance.

One of the biggest problems in the UK is unqualified tradespeople taking on projects that are outside of their expertise. While Checkatrade, Rated People and The Guild Of Master Craftsmen etc are good places to start your due diligence process, we suggest you also check your tradesperson is a member of a specialist association such as ASUC. (Side note: Which is best Checkatrade or Rated People?)

We also recommend taking out specialist renovation home insurance to protect you during the underpinning work. This can be a reassuring backup insurance policy in addition to the liability insurance your builder should have in place.

Can I Claim the Cost of Underpinning on My Home Insurance?

Most instances of subsidence are covered by home insurance policies although not if the property is new and is still covered by a new building warranty. As all policies are different, check your policy paperwork and the small print.

Get an Underpinning Price Today

We’ve teamed up with Bark who can supply you with quotes for underpinning work from their network of specialists in the UK.

Just tap the button below and fill the form with details of your project: