New Drain Installation in London
Extensions, garden rooms, new bathrooms and outbuildings all need waste to go somewhere lawful.
We design, dig, lay and connect new runs with the falls right and the paperwork done.
New drain installation in London: what the price includes
- Design and Building Control. Falls, access points and materials specified to Part H, with inspections booked and passed.
- Connections to existing runs. New chambers cut into live runs without flooding anything, sequencing matters and we’ve done it before.
- Water company approvals. Building near or over a public sewer needs a build-over agreement, we handle the application before anyone digs.
- Soakaways and surface water. Rainwater handled lawfully, soakaway sizing and percolation tests included where needed.
- Built to Approved Document H and signed off. Falls, bedding, inspection access at every change of direction, and connections made properly at the chamber. New drainage is inspected by building control, and work that was never notified is a problem that surfaces at the point of sale rather than at the point of building.
Local conditions we work around
New drainage in London usually has to connect into Victorian combined sewer infrastructure, which brings requirements that catch people out: correct falls, proper interception, and where the connection is to a public sewer, formal approval from Thames Water before the work rather than after. In conservation areas the route and any visible inspection covers are also constrained. We establish the connection point and the consents at survey, because retro-fitting approval is far harder than obtaining it.
Areas we cover
Wherever you are in the list below, the price is the same. Open your area for what tends to go wrong there.
Questions people ask
What does a new drain connection cost?
There is no call-out charge. It is £110 for the first hour, then £45 for each additional half hour, plus the cost of parts, and the same at any hour of the day or night.
Do I need permission to connect to the sewer?
Connecting to a public sewer needs the water company's approval, and building within three metres of one needs a build-over agreement. Skipping this surfaces at conveyancing, expensively. We do the paperwork as standard.
Can you do the groundwork too?
Yes, excavation, bedding, laying, backfill and reinstatement as one contract, one guarantee.
Can I connect to the existing drain myself?
You should not. An unauthorised connection into a public sewer is an offence, and a badly formed junction into a private run causes blockages directly above it for the next twenty years. Connections need forming properly and, where they are into a public sewer, agreeing with the water company.
Do I need a build-over agreement?
If you are building over or within three metres of a public sewer, yes, and it is your water company that grants it, not the council. We identify it at the survey, because discovering it after the foundations are in is expensive.
Foul and surface water together?
Only where the existing system is genuinely combined, which much of inner London is. New build almost always requires separate systems, with surface water to a soakaway or a surface water sewer. Getting it wrong is the most common drainage failure on extensions.