In October 2011, the ownership of most private sewers and drains was transferred to local water authorities for repair and maintenance, relieving hundreds of thousands of homeowners from the responsibility of maintaining sewers on their properties.
However, this transfer means that many homeowners now require prior approval from their local water authority, in the form of a Build Over Agreement, for construction activities involving new foundations, underpinning, piling, or basements within 3 metres of or over the path of an existing public sewer or drain.
What is a build-over agreement?
A build-over agreement is a formal document in which a homeowner provides assurances to the local water authority that proposed construction work will not adversely affect a publicly owned sewer located beneath or nearby. The agreement also outlines the water authority’s access rights to the sewer for ongoing repair and maintenance. If you are planning construction near or over an adopted sewer, it is important to contact the local water authority before commencing any work to understand their specific requirements.
How do I know if there are adopted sewers within my boundaries?
When purchasing a property, you will typically receive a Drainage & Water Search that includes a detailed plan indicating the location of adopted sewers in relation to the property. If any adopted sewers are found within the property boundaries, your conveyancer should raise appropriate inquiries with the seller’s solicitor regarding any issues related to building over these sewers. Additionally, your conveyancer should provide you with a copy of the report from the search, which includes the plan showing the precise location of the adopted sewers. This information is crucial for understanding any potential implications related to the property’s drainage infrastructure.
What are the benefits of a build-over agreement?
Conservatories and extensions are common culprits when it comes to properties being built over adopted sewers. If construction occurred after the sewer was adopted and no build-over agreement was obtained beforehand, the local water authority has a legal right to access the sewer on the property, even if it requires damaging or demolishing the structure above the sewer. While most water authorities aim to minimise damage, they are not obligated to restore the property to its original state. However, if a build-over agreement is secured, the water company cannot remove or demolish the structure over the sewer, and they are responsible for repairing any damage caused during sewer access and repair.
What if a property doesn’t have a build-over agreement?
The most common and efficient way to address the risk of a property being built over an adopted sewer is for the seller to provide the buyer with an indemnity insurance policy. This policy safeguards future property owners from financial losses in the event that the local water authority damages the property while accessing or repairing the adopted sewer underneath it. However, this option requires approval from the buyer’s lender and is not viable if the existence of the building over the sewer has been disclosed to the water authority.
Another approach is for the buyer to request that the seller arrange a CCTV survey of the sewer, sharing the footage with the local water authority. The goal is to obtain approval of the sewer’s condition and a comfort letter assuring that the authority will not take action to demolish the building over the sewer. This step also requires approval from the buyer’s mortgage lender.
The most comprehensive option, albeit more costly and time-consuming, is for the buyer to insist that the seller obtain a retrospective build-over agreement with the local water authority before exchanging contracts. While this provides robust protection, there is a risk that the authority may require additional work that the seller cannot afford.
If you are planning to sell a property that may be built over an adopted sewer, it is advisable to discuss these options with your conveyancer before listing the property for sale.
