Gas pipework alterations and meter moves in north and east London

There are two parts to the gas in your home. The service pipe brings gas from the main in the street to your meter. That belongs to the gas network, which in north London is Cadent. The installation pipework runs from the meter to your boiler, cooker and fires, and that is the householder's or landlord's to maintain (HSE). A Gas Safe registered engineer works on the installation pipework.

If your renovation needs the meter in a new place, Cadent's service alteration process applies. You apply online or by phone, discuss with your gas supplier whether the meter needs changing, accept a quote, and Cadent surveys the site. Cadent says it takes on average 6 to 8 weeks from payment to the work, subject to survey and council permits. Cadent has a price estimate tool on its site for an indicative cost.

Cadent asks for the distance of internal pipework needed to reconnect the boiler to the meter's new position. Once the meter has moved, a Gas Safe registered engineer reconnects and tests your pipework. Book that early so it lines up with Cadent's date.

Rear extensions on terraces in Walthamstow, Leyton and Tottenham often move the kitchen, and sometimes swallow the old external meter box. Gas pipe cannot just be buried in a new floor or boxed in without thought. It needs to be the right size for the appliances it feeds, protected where it passes through walls, and installed so it can be tested in future. A new combi needs more gas than an old boiler, and an undersized pipe from the meter is a common reason a new boiler underperforms. The survey for a new boiler checks this.

HSE says landlords must keep installation pipework in a safe condition. The yearly gas safety check covers appliances and flues, not the pipework itself, so HSE recommends asking the engineer to do a tightness test on the whole system and look over the pipework at the same visit. It also recommends a pipework check when tenants move out, because old cookers are often pulled off and valves left shut. In older London houses, pipework can be decades old, partly hidden under floors and patched by different people over the years. A tightness test at the meter tells you quickly whether the whole system holds gas.

If you are renovating, ask for the gas pipework to be planned and tested before plaster, screed or flooring goes down. Gas Safe Register advises checking where gas pipes run so they are not hit during DIY or building work. Mark the route on a photo or drawing for the future. Testing before the floor is finished is far easier than lifting a new floor later to find a leak.