A Quick Guide to Meeting Requirement H4 of the Building Regs

Check the sewer records at your local council or with your regional water authority to see if any cross your land

Check the inspection chambers on your land to see if any serve drains from other properties (and are therefore adopted now as public sewers)

If these checks shows drains are present and within 3m of your proposed building, check inspection chambers and sewer maps to see whether they are minor sewers — up to 3m deep and 225mm diameter

If deeper or larger, and within 3m, you will need to enter a build over sewers legal agreement and this may result in changing your plans and/or applying to divert the sewer

If no deeper than 3m and no larger than 225mm diameter, check whether your building control body has a protocol agreement in place with the water authority to act on their behalf, in designing the protection to the minor sewer. This will avoid the need to enter into the legal agreement process