I thank my hon. Friend Mark Pawsey for raising this important issue. As he said, before 2011, home owners were responsible for their sewers and pipes. Should anything have happened to those pipes, it was down to the home owners to cover the expense, and attempt to recover costs from those neighbours who shared the same pipes.

In October 2011, the Government implemented the water industry regulations transferring the ownership of, and responsibility for, private sewers and lateral drains to the water and sewerage companies. My hon. Friend rightly pays tribute to the sterling efforts of his constituent, Pam Brockway and others, in bringing this unfair practice of passing the cost on to individual home owners to the attention of Government, which resulted in those legislative changes.

I have also had experience of this matter in my own Constituency. I remember meeting in one of my surgeries an elderly lady who was being bullied by a cowboy builder to sign on the dotted line to say that she would pay £10,000 towards the upkeep of a private sewer that was collectively owned. She resisted that, but I have heard of many other such practices, often involving vulnerable people.

In addition to preventing unexpected and substantial sewer repair Bills going to individuals, the 2011 transfer has also meant that the sewer network can be systematically upgraded over time. The consequence has been a regularly maintained and more resilient sewer system.

The 2011 transfer has resulted in a greater focus on the 2010 building regulations. The regulations set out how buildings should be built or improved. Although no changes were made to the 2010 building regulations, the transfer regulations enabled building regulations more effectively to achieve their aim of ensuring that new buildings and extensions are constructed in a way that does not adversely affect the sewers. Given the general lack of awareness among home owners before the 2011 transfer, private sewers were at great risk of compromise or damage when construction took place—ultimately at the considerable expense of individual home owners.

The local authority, or approved private sector building control body, has the final say on whether any works comply with building regulations, although they must have regard to any views expressed by the sewerage undertaker, such as when a sewer is within 3 metres of the proposed works. Furthermore, even if the developer disagrees with the building control body, there is the option to apply to the Department for Communities and Local Government for an independent determination.

I wish now to address some of the points made by my hon. Friend. He pointed out that the 2011 transfer could not resolve all the issues. He has highlighted six important issues including: the legal requirement for a build-over agreement; charges levied by water companies for build-over agreements and works to be done; the time taken for the process of agreement; and the paucity of information about where the sewers are located.

First, there is no formal legal requirement to obtain a build-over agreement. However, it is considered good practice to obtain the permission of the water company responsible for a sewer or drain affected by any proposed building project, and that is also encouraged by the approved building regulations guidance. Water and sewerage companies are best placed to advise on suitable actions or possible risks to the sewerage network as a result of building work.

My hon. Friend makes a very good point regarding the variance in the charges levied by water companies for build-over agreements. We all want to see that any such costs are reasonable, proportionate, appropriate and consistent; otherwise we will have saved home owners one expense through the 2011 transfer only to expose them to new costs.

My hon. Friend highlights the importance of guidance. He is right that the solution to these and many of the other issues would be a joint industry-developed code of practice governing the processes of securing a build-over agreement and bringing transparency to the costs involved. A code of practice could also address any issues concerning timing and make it clear where responsibilities lie for repairs to sewers when the construction is being carried out or who retains liability for the quality of the construction and its potential impact on the sewer underneath in the long term.

The Glass and Glazing Federation has already taken the initiative in drawing up a draft. The Government have been talking to the water companies about working with the Glass and Glazing Federation to reach a common approach and I am told that we can expect positive developments soon. I welcome that, but I want to see even greater momentum behind the idea of the code of practice. In advance of the debate, I contacted the Under-Secretary of State for Environment, Food and Rural Affairs, Dan Rogerson, who is responsible for water, forestry, rural affairs and resource management. The Under-Secretary intends to write to Water UK, the organisation that represents the water companies, to encourage that development. I hope that from this debate we will see momentum behind the idea of a code of practice, because given that there is no formal legal requirement for the build-over agreements, which are only set out in guidance, home owners are in a strong position to get credible guidance that prevents water companies from charging excessively for these agreements.