Kitchen Specification in London Renovations: Appliances, Layout, and What Gets Overlooked

The kitchen is the most technically complex room in a residential renovation. It concentrates more trades — joinery, electrical, plumbing, gas, ventilation, tiling — in a smaller area than any other space, and the specification decisions interact with each other in ways that are not always obvious. A decision about appliance selection affects ventilation requirements. A decision about worktop material affects joinery tolerances. A decision about island positioning affects structural implications. Getting these right requires more coordination than most kitchen renovations receive.

This guide covers the specification decisions that determine the outcome of a kitchen renovation — with particular attention to what gets overlooked.

Layout fundamentals

The working triangle (hob, sink, refrigerator) remains the organizing principle of kitchen layout, even in large open-plan spaces. The three points of the triangle should be:

• —Between 1,200mm and 2,700mm apart (too small and the kitchen is cramped; too large and it is inefficient)
• —Not intersected by a major through-route — a kitchen where traffic passes between the hob and the sink during cooking is a safety and ergonomics failure
• —Accessible without obstruction from oven doors, dishwasher doors, and drawer pull-outs — this is the most commonly under-checked spatial constraint at design stage

In a galley kitchen, the two runs should be at least 1,200mm apart clear (1,000mm is the regulatory minimum for a single-user kitchen; 1,200mm is the functional minimum for two people).

For an island, allow 900mm clear circulation on all working sides. An island specified at 600mm clearance looks acceptable in a kitchen showroom and feels cramped in a working kitchen.

Appliance specification

The appliance brand and model must be confirmed before joinery is designed. Kitchen furniture is built to the appliance's cutout dimensions; changing the appliance after cabinetry is ordered typically means reordering doors or carcasses.

Hob: induction is now the default specification in quality London renovations. It heats faster than gas, is easier to clean, and does not require a gas connection (relevant in all-electric buildings and buildings where gas infrastructure is being simplified). The principal constraint is electrical supply: a 70cm induction hob typically draws 7.2kW and requires a dedicated 10mm² circuit with a 40A MCB. This must be specified to the electrician at first fix. Specifying induction at second fix on a circuit designed for a 2.5mm² electric hob is not viable.

Gas hobs remain the preference of some professional cooks. They require a gas supply at appropriate capacity (typically 20mm copper from the meter to the hob position), a gas isolation valve within reach below the hob, and a compliant extractor (minimum 150 l/s for a gas hob under Part F).

Oven: built-in single or double oven in a tall housing is the most common configuration. Pyrolytic self-cleaning is standard at quality price points and worth specifying — manual oven cleaning in a built-in oven is impractical in a sealed kitchen environment. Steam combi ovens (Gaggenau, Miele, V-Zug) are specified in high-end projects and require both electrical supply and a mains water connection with waste — this must be coordinated before joinery is installed.

Refrigeration: fully integrated fridges (hidden behind furniture panels) are the correct specification for a kitchen where visual uniformity is a design priority. They are more expensive and have slightly lower capacity than freestanding equivalents at the same width. American-style side-by-side fridges require 900mm of clear width and plumbing for ice makers — confirm both before committing to a position.

Dishwasher: integrated as standard. 600mm is the universal footprint. A second drawer dishwasher (Fisher & Paykel) is increasingly specified in larger kitchens where occupants want to run smaller loads independently.

Sink and tap: undermount sinks (fixed below the worktop) are cleaner and more hygienic than inset sinks in a stone or solid surface worktop. They require a minimum worktop thickness of 20mm and a routed underside recess — confirm with the stone fabricator before ordering. Boiling water taps (Quooker, Zip HydroTap) have become a near-standard specification in quality London kitchens. They require a small under-sink unit (150–200mm deep) and a cold water mains connection; confirm under-sink space before specifying.

Ventilation: the specification that fails most often

Kitchen ventilation is the most commonly under-specified element. Part F requires:

• —Minimum 30 l/s (108 m³/h) intermittent extract adjacent to a hob, or 13 l/s continuous
• —For gas hobs: minimum 150 l/s (540 m³/h) — significantly higher

In practice, recirculating extractors (which filter through carbon rather than ducting to outside) are often installed because ducting to outside is complicated. Recirculating extractors remove grease and odour but do not remove moisture — in a well-sealed kitchen, moisture accumulation from cooking is a real issue. For any quality renovation, a ducted extractor is the correct specification.

Ducting routing is the constraint. In a rear extension kitchen, ducting typically runs through the ceiling void and exits through the flat roof or a rear wall. The duct diameter must be adequate for the extractor's flow rate (a 150mm duct is the minimum for a 600mm wide extractor; 200mm for higher-output models), and the total duct length affects performance — manufacturers publish derating tables for duct length and bends. Each 90° bend is typically equivalent to 1–2m of straight duct.

Agree the duct route with the contractor before the kitchen is designed. Trying to route a 200mm duct through a finished kitchen ceiling is a significant disruption.

Worktop materials

Natural stone (marble, granite, quartzite): the premium specification. Each slab is unique; clients should select the actual slab rather than specifying a generic material type. Marble is softer and more porous than granite — it etches (loses surface sheen) from acid contact (lemon juice, vinegar) and stains if not sealed. Appropriate for clients who accept patina as part of the character. Granite and quartzite are more resistant. All natural stone requires sealing on installation and periodic resealing.

Engineered quartz (Silestone, Caesarstone, Dekton): consistent appearance, very hard, low maintenance. Dekton (an ultra-compact sintered surface) is particularly resistant to heat and scratch. Engineered quartz cannot tolerate UV light at length — it is not appropriate for external or conservatory applications. It looks uniform rather than natural, which is either a virtue or a limitation depending on the client's preference.

Solid surface (Corian): seamless joins, hygienic, repairable (scratches can be sanded out). Less prestigious than stone but technically excellent for high-use environments. An integrated Corian sink and worktop with no visible joint is a clean and practical specification.

Timber: warm and traditional. Requires regular oiling (every 3–6 months depending on use) and cannot be used adjacent to a sink without a stone or solid surface insert. Appropriate as an island top or in secondary positions; less appropriate as primary worktop material in a heavy-use kitchen.

What gets overlooked

Socket positioning: in a kitchen, sockets are needed at worktop height (150mm above worktop) and in islands. At first fix, sockets are placed approximately — if the designer has not specified exact positions relative to the cabinet layout, they will often end up behind appliances or inside corner units. Get a scaled kitchen drawing and overlay socket positions before the electrician first-fixes.

Bin drawer dimensions: a pull-out bin drawer requires 300–450mm of cabinet width and does not work in all positional configurations. Decide on bin storage before joinery is designed.

Water softener: London's hard water causes limescale on all water-contact surfaces — glass, stone, brassware, appliances. A whole-house or kitchen water softener (Harvey, BWT) requires under-sink space, a drain connection, and a salt top-up access point. It is a functional improvement that is very difficult to retrofit once the kitchen is installed. Consider at design stage.

Kickplate lighting: LED strip at plinth level creates a floating effect at night and provides practical orientation lighting. It requires a low-voltage cable to the plinth zone at first fix — easily provided if planned, awkward to retrofit.

Integrated speaker cable: if the client wants in-ceiling audio in the kitchen, the cable must be run at first fix. Retrofitting speaker cable after plastering requires surface trunking or significant disruption.