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What to consider if buying a renovation plot where Japanese knotweed is present

Here at Ashton Bennet, we’re all too familiar with the dreaded Japanese Knotweed plant and – more specifically – how much of a night mare it can be to remove it as part of a building or renovation project.
So, we thought we’d share our thoughts on what you need to know if you are thinking of building or renovating where this pesky plant is present.

How do I know if it’s present?

It can be pretty difficult to spot this plant, as it takes on different guises depending on the time of year. Clever! In early spring, its shoots appear and grow quickly into canes. As these canes grow, their heart-shaped leaves uncurl and will turn to green. By early summer Japanese Knotweed will be fully grown with distinctive, purple-specked canes that can reach up to three metres high.

Around the end of October/early November, the plant will look dead – but don’t be fooled – there are still shoots below ground level waiting to re-appear next year!

How can it affect a building or property renovation project?

Basically, Japanese Knotweed will break through any weaknesses in hard surfaces in order to reach the light and grow further. That means it can easily break through cracks in paving, joins in concrete or splits in drains causing havoc very quickly.

We have even come across cases of the pesky plant growing within cavity walls, where it becomes a real issue by growing out of vents and air bricks that are 2metres above ground level. Essentially, when it grows within a cavity wall, Knotweed is able to force the two skins of the wall apart, causing potentially devastating long-term damage.

This is why it’s so important to completely eradicate Japanese Knotweed at the source before undertaking any building or renovation project where it is present! But how do you do this?

If you are planning to build or extend on land where Knotweed is present, there’s no option but to remove the weed-infested soil, which requires the skills and protocol of experts like Ashton Bennett. Simply building over the top of Knotweed will mean it comes back to haunt you very quickly!

Most Knotweed removal has to happen during the summer months when it is ‘in bloom’, which can be restrictive on building schedules and timescales. Other options outside of the summer months that focus on treating the soil are available through ourselves, and can drastically speed up the removal process.
Whatever or whoever you use to remove Japanese Knotweed, make sure you get a guarantee for the work and evidence of a treatment plan, as these are required by most lenders if you decide to sell the property or seek additional mortgage finance.

What are the benefits of a basement conversion and why should I do it?

Thinking about converting the basement in your home into a space that’s a little more – well – useful? Then you’re not alone.

Here at Ashton Bennett HQ, we weren’t overly surprised to learn that research released by Direct Line in February revealed that 75% of all basement conversions in the UK take place in London. Our experience delivering basement impact assessments for this type of project often sees us visiting the capital, where most of the projects of this type that we work on take place.

This got us thinking though. Converting a basement can be a costly process, but it can add serious value to a home or property (particularly in London where space comes at a major premium). So, other than space, what else would trigger someone to convert that dark, dingy space into something more suitable for keeping up with the Joneses?

They’re great for growing families

Along with a 15% increase in the number of UK families in the last 10 years comes extra children, and the need for extra space. Rather than going through the hassle of looking for a new property and leaving the one they love, a basement conversion can solve the space crisis. They are great for creating extra bedrooms, another living room, or even a dedicated children’s play area – without having to uproot the whole family in the process.

They shelter sports cars

With a large proportion of London’s mega-rich owning more than one prestige car and looking for somewhere safe to store them (other than the road side!), a basement-to-garage conversion can be the best solution, depending on the size of the space available, of course. Why leave your Porsche out on the street when it could be tucked away safely under your very own living room?

They help with energy efficiency

Improved wall and floor insulation as part of a basement conversion has a positive effect in that it prevents your home from cooling down or overheating too quickly, instead helping to retain heat and control temperature variations more effectively. It’s thought that a house with a basement ca actually be up to 10% more thermally efficient than one built solely above ground. So, if you are looking at ways to cut your energy bills, a basement conversion could help you.

They can make use of a sloping site

Basement conversions can be a great way of making good use of a sloping site at your home. Instead of levelling it, there is the option to create a semi-basement by doing a cut and fill, digging out from the slope and then levelling to form a base on which you can then build. Problem solved!

Basement beware….

If you like the sound of the above and are thinking of converting any sub-surface space, remember to take professional advice before you begin. There are numerous tests and reports that need to be carried out in order to assess suitability and the scope of work to ensure that the project is delivered in a safe manner and according to building and planning regulations.

Done properly, converting sub-surface space to add to your home can add value to your property and bring a new lease of life to the space you live in for years to come.

Need more information on this topic? Why not contact Ashton Bennett today.