A kitchen extension in Dartmouth Park is designed on the assumption that the rear elevation will be seen. On the sloping streets between Highgate, Kentish Town and Hampstead Heath, the backs of Victorian and Edwardian houses and the gardens behind them are visible from the houses below and across, so the familiar argument that a rear addition is hidden and therefore uncontroversial simply does not hold. Camden applies its Dartmouth Park Conservation Area guidance when assessing proposals within the conservation area, and that guidance takes the garden setting and the rear fabric of these houses seriously. Whether a specific NW5 address sits inside the boundary should be confirmed before anything is assumed, but where it does, the extent of the glazing, the roof form of the addition and the way new work meets old brickwork all belong in the first sketch rather than the last one.
The question we are asked first is how much glass the rear can carry. A full-width sliding screen, a run of slim steel-framed doors, a lantern over the dining end and a discreet band of rooflights are all achievable, but they are not interchangeable, and each changes how the extension reads from the garden and from the properties looking back at it. A flat roof with a slim parapet keeps the addition low and subordinate to the host house. A lantern lifts daylight into the middle of a deep plan but raises the extension's profile and, on a hillside, presents its glass to anyone standing higher up. Frame proportion matters as much as glazed area: a smaller number of tall, well-proportioned openings above a solid brick base usually sits better against a Victorian rear wall than an uninterrupted wall of glass. We test the options in elevation and in section before committing.
Glass that works beautifully in November can be unbearable in July. Once the glazing is sized, we check the orientation of your particular rear elevation — which has to be confirmed address by address rather than assumed for the area — and then design the shading, the glass specification and the ventilation as one thing. In practice that means a considered solar-control specification rather than clear glass everywhere, a reveal or overhang that shades high summer sun without stealing winter light, openable area distributed so that air can cross the plan rather than only at the garden end, and enough purge ventilation to shed heat on a hot evening. Building regulations cover ventilation and insulation alongside structure and drainage, and Camden has adopted Dartmouth Park energy-efficiency guidance, which should be checked for how it bears on a particular proposal — so we treat the comfort and fabric of a new extension as design work rather than a specification chosen at tender.
Drainage decides more kitchen layouts than taste does. The back of a Victorian terrace typically carries a soil stack, a rainwater downpipe and a gully within a metre or two of the wall you intend to open up, frequently with an inspection chamber in the ground you intend to build over and a drain run shared with the neighbours. Building over or near a shared drain or public sewer requires the drainage undertaker's agreement, and that is a programme item rather than a formality. The new kitchen's waste, the rainwater coming off the extension roof and any surface water from the reworked garden edge all need somewhere to go with a workable fall, and the finished floor level, the insulation zone and any underfloor heating sit on top of that decision. We survey what is actually there before the sink, the hob and the run of units are placed.
Extract is the other service that is far easier to solve on paper than on site. A serious cooking hood needs a duct with a real route and a real termination, and on a Dartmouth Park rear elevation that termination is visible — a grille cut through character brickwork late in the build is precisely the detail a case officer and a neighbour both notice. Ducting an island hood is harder again, because the run has to pass through the new floor build-up or the roof, which has to be resolved before the structure is designed rather than after it. Houses here sit close together, so the noise of an extract terminal near a neighbour's window is a genuine consideration. We fix the duct route, the terminal position, the gas and electrical runs and the appliance ventilation alongside the layout, so the services are designed in rather than chased in.
Around all of this sits the neighbour relationship and the consent route. Camden assesses daylight and sunlight to neighbouring windows using the established BRE tests, and an extension kept low near the boundary, with its roof stepped away from a neighbouring flank window, usually stays within them. Right to light is a separate civil matter that a planning consent does not resolve, so where the new rear wall approaches a neighbour's window we flag it early rather than let it surface after works start. Building on the line of junction, or excavating within three or six metres of a neighbour's structure, engages the Party Wall etc. Act 1996 independently of the planning decision. We survey, test the design against these constraints, produce the planning drawings and then the building regulations package — and we give an honest reading of the risk. We do not promise approval.
The finished project should feel like it was always part of the house. That is a matter of proportion and of detail: the height at which the new roof meets the original wall, whether the brickwork matches or deliberately does not, how the threshold to the garden is formed and drained, and where the daylight actually falls at the back of the plan once the original rear rooms are opened into the new space. Opening up a Victorian rear wall means a structural opening and a beam that has to land on something, and that structure has a habit of dictating ceiling heights and duct routes if it is not coordinated early. We resolve the structure, the services and the elevation together, so that the room you occupy is the room that was drawn.
