A Wandsworth kitchen extension is decided by the plan of the ground floor as much as by the footprint added to the garden. The terraced house typically runs two reception rooms front-to-back with the kitchen tucked at the rear, often against a narrow side return, and the brief nearly always the same: one open kitchen-diner across the back, connected to the retained period rooms rather than sealed off behind them. That connection is the real design work. It means deciding which walls hold the front rooms' character and which come out, where the cooking zone sits relative to the dining table and the garden doors, and how far the new space can borrow light and volume from the house without stripping the period plan of its rhythm. We resolve that arrangement before any elevation is drawn, because the position of the cooking zone, the run of the units and the line of sight from the front of the house to the garden are settled by it, and every later decision on structure and services follows from where those pieces land.
The machinery is what most often derails a kitchen here, so we fix it first. A serious kitchen needs a ducted extract discharging to outside air, and on a terrace the only elevation available is usually the rear or a side-return flank shared with a neighbour. Around that extract sit a boiler flue, a condensate run, and often a soil vent for a new utility or cloakroom tucked into the plan. On an unconstrained house those are second-fix afterthoughts; where the property falls within a conservation area they become external changes that have to be justified on the drawings. We fix the position, size and appearance of every termination early, because a duct route with too many bends will not deliver the extraction the hob is rated for, and moving it after consent means redrawing the room.
Daylight, not floor area, is the problem at the back of a deep terrace. A kitchen at the rear of a two-reception plan can only be lit from its garden end and from above, so the useful moves are a generous garden opening and a rooflight over the part of the plan furthest from it — frequently the new dining zone or the retained middle room. Where the kitchen combines a rear extension with a side-return infill, a rooflight along the infill glazes the previously dark centre of the house. Each of those is a visible external change on a period roof, so where a conservation area applies we design the glazing and the daylight case as one exercise, testing area, orientation and shading so the room is bright in February rather than unbearable in July, and the rooflight earns its place on the roof by lighting the part of the plan a window never could.
Turning several small rooms into one kitchen-diner is a structural job with a neighbour attached. The wall coming out is often a spine wall carrying the floors above, or a chimney breast that stiffens the terrace, so a structural engineer sizes the beam and — just as importantly — resolves where its load actually goes down to the foundations. In a terrace that beam commonly bears into the party walls shared on both sides, which engages the Party Wall etc. Act 1996 independently of any planning decision. Where the kitchen also takes in a side-return infill, the new structure sits hard on the boundary and the party wall procedure covers that junction too. We identify the notifiable neighbours at design stage so the notices and any award do not hold up the start on site.
Below the finished floor sits the part of the job nobody photographs but everybody feels if it is wrong. An island wants water, waste and power beneath a slab that will usually be insulated and fitted with underfloor heating, so its position has to be committed early: a drainage fall is far harder to move later than a run of cabinets. New below-ground runs have to reach an existing connection, and building over or close to a public drain — common where the kitchen extends across the rear or down the side return — can require a build-over agreement with the water authority. We set the island, the sink, the utility and the appliance runs against the drainage strategy at the outset, so the layout the household actually wants is the one that can be plumbed rather than the one the pipes force on it.
An open-plan kitchen at the foot of the stairs is also a fire question, which building control takes seriously in a tall terrace. Opening the kitchen into the hall or stair removes the separation that protected the escape route, so the usual answers are a fire-resisting lobby, a protected alternative route, or a suppression system such as a mist or sprinkler installation designed in from the start. Building control then wants structure, fire, insulation, ventilation, drainage and stairs all evidenced together. From there the route is a coordinated one: we survey the house, confirm which consents genuinely apply to the address, then produce the planning drawings and, once the principle is settled, the building regulations package for construction. We advise honestly on the constraints and do not promise approval, setting out the notifiable neighbours, the drainage agreements and the conservation questions as risks to be managed on a programme rather than surprises to be met on site.
