Should I go all-electric or keep gas?

All-electric increasingly standard — induction outperforms gas in responsiveness and control; ovens equivalent; eliminates flue and gas safety risks; improves EPC. Keep gas only if user strongly prefers gas wok cooking or property is off-mains-electricity-upgrade. New builds frequently designed all-electric; renovations split 60/40 toward electric in 2026.

What pressure does a boiling-water tap need?

Minimum 1.5 bar dynamic (3 bar preferred). Quooker, Fohen, InSinkErator all specify minimum operating pressure. If house pressure is below 1.5 bar (common in older London properties), install booster pump or accumulator (£950–£2,800). Don't install boiling tap on inadequate pressure — short-cycles, fails, voids warranty.

Can I move the sink position?

Yes but waste routing is the constraint. Each metre moved away from soil stack requires verified 1:40 fall and possibly AAV. Beyond 3m horizontal run without venting violates Part H. Common London move: sink from rear wall (under window) to island — needs detailed waste routing under floor. Plan at first-fix; don't decide late.

Kitchen Plumbing Services Design London 2026 | Builderr

How Should Plumbing and Services Be Designed in a London Kitchen?

London kitchen plumbing first-fix: 15mm hot+cold supplies to sink, dishwasher, fridge (ice maker), boiling-water tap; 32mm waste from sink and dishwasher to soil stack (max 3m before AAV or vent); isolator valves at every appliance; mains pressure 1.5–3.0 bar minimum. Gas (if retained): 22mm flexible to hob, 15mm to oven — Gas Safe registered installer mandatory. Plan services first; cabinets follow.

Plumbing first-fix

Hot and cold supplies: 15mm copper or barrier pipe to sink (with isolators each side), dishwasher (15mm cold + isolator), fridge with ice/water dispenser (15mm cold + isolator + pressure-rated tap), boiling-water tap if installed (15mm cold + isolator + cartridge boiler under counter). Mains pressure verification: many London 1900s properties run at 0.5–1.0 bar — inadequate for boiling-water taps (need 1.5+ bar), pressure-balanced showers, and high-flow taps. Solution: mains pressure booster pump (£950–£2,800) or accumulator tank. Hot water: combi boiler delivers 12–18 L/min adequate; pressurised cylinder system (Megaflo) delivers higher flow with no flow restrictor. Island sink: 15mm supplies through floor void; loop the loop to avoid airlocks.

Waste and drainage

Sink waste: 40mm trap then 32mm or 40mm waste pipe to soil stack within 3m horizontal run (Building Regs Part H). Beyond 3m requires anti-siphon (AAV) or independent vent. Dishwasher waste: tee into sink waste downstream of trap (between trap and soil) with non-return valve. Washing machine + dishwasher on same standpipe: needs 75mm trap depth and AAV. Island sink waste: trickiest part of island design — needs floor void deep enough for 40mm pipe + 1:40 fall + connection to soil stack. Suspended timber floor: usually possible (200mm joist depth). Solid concrete floor: requires saw-cutting trench or routing within insulation/screed depth — verify at design stage.

Gas, electrical and isolators

Gas (if retaining): 22mm steel pipe to hob with bayonet socket + cooker hose, 15mm to gas oven, gas isolation valve inside cupboard accessible. Gas Safe registered installer commissions and certificates. Many London renovations now eliminating gas — all-electric induction + electric oven simplifies install and improves EPC. Electricity: dedicated 32A radial for hob (induction draws 7.4–11.2 kW peak — needs own breaker), 16A for oven (sometimes shared with hob on a 32A), 13A spurs for fridge, dishwasher, microwave, fridge, boiling tap. Sockets above worktop minimum 4 doubles, more is better — kettle, toaster, mixer, blender, charging dock. USB-C outlets in 2 of those. Isolator switches at every appliance — visible, labelled — for service and emergency.