Can i build over drains

Q If my project requires work, who can do it? Latest Posts Proud to be Approved Installers! October 22, Resin Driveway Heroes November 16, New Resin Surface Products November 7, Do you need planning permission for a conservatory views. Artificial Grass — Before and After views. The below image from Greenway Associates clearly displays the boundaries for exemption.

With conventional foundations this is not allowed, however, with Local Authority approval, you could span over the manhole using ConservaBase. Unfortunately, you cannot build your conservatory over a manhole using conventional concrete foundations since manholes need to be accessible by the Water Authority.

They need to have full access to the sewer system. Also, internal systems such as manholes have an increased risk of flooding, therefore building over one would never be advised. Instead, you could look to relocate your manhole, if it is affecting your conservatory build plans. However, with the relevant authority approval, you could use ConservaBase with a built-in removable access panel to span the manhole and still leave it accessible if and when needed.

This can be a very simple and cost-effective way of avoiding the need to relocate the manhole. If you would like to relocate a manhole we would suggest you initially consult your local water company to make sure you are allowed to do so. If permission is granted there are many local companies who will be able to carry out the required work.

However, it is worth bearing in mind that this can prove to be a costly procedure, so should be something you consider budgeting for if necessary. Unless your conservatory meets the above explained exemptions, you must have approval from your local sewerage company prior to building over a drain. There are many firms which can carry out CCTV surveys that will indicate the condition of the drains as well as their location and depth.

You are strongly advised to seek advice from a builder, architect, drainage engineer or your local authority building control department before committing to or commencing work. You may need to increase the size of your gutters and rainwater pipes, or add new rainwater pipes. Information on sizing gutters and rainwater pipes is given in Approved Document H.

Additional rainwater pipes can discharge onto the ground, or into new or existing underground pipework. If you decide to allow rainwater pipes to discharge onto the ground, you need to make sure the water will not damage foundations eg. A larger roof area will increase the amount of surface water.

It is preferable to keep the extra volume on site, in order to avoid increasing flood risk elsewhere. Rainwater can be kept on site by using a soakaway or some other way of allowing it to soak into the ground referred to as infiltration , or stored and used for toilet flushing or garden watering known as rainwater harvesting. Approved Document H gives advice on where to site soakaways, how large they should be and how they should be built. Where it is impractical to use infiltration eg.

Surface water must not be discharged into a foul drain or sewer. In order to avoid increasing flood risk elsewhere, it is preferable for these to be sloped towards permeable ground or to be made of pervious materials. Buildings and extensions should not be constructed over a manhole or inspection point on a sewer. The extension must also maintain a 3m zone to enable the sewer to be reconstructed in the future if the water authority deem it necessary, and that zone should also be accessible to a mechanical excavator, depending on the depth of the drain.

Building Regulations also restrict the length of drain or sewer that can be built over to a maximum length of 6m. Lastly, if the drain is greater than mm in diameter or greater than 3m in depth, then again special consent will be required, which could affect the viability of the project. In most cases applying for permission is simple and can be done using a self-certification questionnaire online, although some water authorities are much more helpful than others and a simple national system would help remove regional variations.

If a build-over agreement is required, then a number of important restrictions are likely to apply. These vary by water authority, but typically include:.