Japanese Knotweed Taking Over Your Garden? Here’s What RICS Category B Means

Last week we looked at RICS Category A. This week we are looking at RICS Category B.

If Japanese Knotweed is starting to take over your outdoor space but hasn’t yet caused structural damage, it may be classed as RICS Category B.

This category applies when knotweed is within the property boundary and is starting to affect how you use your garden or outside space. It might be growing quickly, blocking access, or spreading near paths, fences, or patios. While it hasn’t damaged your home, it’s clearly a problem—and lenders will want to see action.

Most mortgage lenders will require a Knotweed Management Plan carried out by a PCA-registered contractor. This plan should include a long-term treatment programme and a 5 or 10-year insurance-backed guarantee (depending on the lender) to give lenders and buyers peace of mind. Some mortgage lenders may keep some money back until the treatment plan has been paid for (known as a retention). Other lenders may not lend on RICS Category B.

The presence of knotweed in this category can impact your property’s value, depending on how severe the spread is and how early treatment begins. That’s why it’s important to act quickly—the sooner it’s assessed, the better your options.

If you think your property falls into Category B, don’t wait. Get a specialist in, start treatment, and you’ll be in a much stronger position when it’s time to sell, remortgage, or just enjoy your garden again.