In 2015 the Government set out with the ambition to deliver one million ‘net additions’ to the housing stock by 2020, which included conversions and changes of use. Property developers had two clear options: build more housing or renovate and convert existing buildings.
In January 2021, official estimates suggested that, in order to meet demand in England, 345,000 new homes needed to be built every year. Despite a record year in 2019/20, statistics from the Ministry of Housing, Communities & Local Government revealed that only 243,770 homes were delivered, just over 100,000 short of the requirement.
As time is critical for property developers, it’s incredibly important that there are as few setbacks as possible and that they are rectified quickly. With the obvious need for new homes, house builders and developers need to find stable ground to build on, and foundation soil that is protected against environmental factors.
With extreme weather in the UK becoming more common, new buildings must be able to withstand the elements to prevent foundation damage and subsidence. Building as quickly and as cheaply as possible, however, can increase the risk of structural issues and cause longer-term problems.
It’s common for new buildings to settle in their first few years. This shouldn’t be a cause for alarm unless the movement is severe or ongoing as it may be caused by subsidence. In such cases, re-homing homeowners or tenants and opting for traditional concrete underpinning work can be a slow and tedious solution. More modern methods, such as Mainmark’s ‘key-hole surgery’ Teretek® resin injection approach, offer a more cost-effective and less invasive alternative. For builders, developers and property owners this solution could save weeks, often with no need to relocate.
Conversions and renovations
If done correctly, renovation can be a much quicker way to provide new homes compared to new builds. Starting with the foundations and ensuring they are sound is the first step to preserving a building’s longevity and will allow for safe and reliable refurbishments to take place. If this is not addressed first, upgrading expensive interior fixtures like doors and windows can become an issue, should the property subside. This is time-consuming and expensive to fix, and the interiors may need to be re-replaced once again.
When assessing the foundations in an existing structure, understanding the soil type is critical. In the UK the most common soil types are clay, sand and silt, fill and organic:
Reactive clay soil swells when wet and shrinks when dry causing subsidence in drier conditions, or heave in wetter areas.
- Sand and Silt
Structures on sand and silt soils often experience settlement caused by flowing groundwater, a natural underground watercourse or a leaking sewer or stormwater pipe.
Fill is earthen material placed and compacted in a hole or depression. Structures built on fill are susceptible to the same issues as those on sand and silt, especially when water washes away finer material. Settlement is worse if the fill is poorly compacted.
Organic soils, especially peat, are weak and highly compressible making them prone to settlement, as the weight of any structure above causes compaction. Primary settlement decreases over time but can total 100s of millimetres, resulting in significant structural issues.
If there is an issue with the foundations of a building that needs to be remediated, the modern method of resin injection will provide a less invasive alternative to traditional underpinning methods. This method allows both ground strengthening and re-levelling the structure, increasing the likelihood of it staying as intended and serving its purpose for the future.
The race to provide new homes and meet targets continues. With careful consideration given to the underlying ground of any building new or old, builders and developers can work confidently in the knowledge that their project has a head start.
For more information about the solutions required to repair the sinking foundations of a building, please visit, https://mainmark.co.uk/residential/foundation-subsidence/.
Victor is one of the Directors at Mainmark UK, with over 10 years’ experience in project management and construction management. Having joined Mainmark in 2009, he has managed projects in Australia, the UK and New Zealand including the remediation of the Christchurch Art Gallery which was shaken by the 2010 and 2011 earthquakes that hit New Zealand’s South Island, the old Bank of New Zealand building in Kaiapoi and Ultima Furniture’s warehouse in the UK.