A rear kitchen extension in Dulwich is really the design of one room: the garden-facing kitchen-dining-living space that opening the back of a family house or villa creates. On the wider semi-detached houses and the larger villas around Dulwich Park, this is a rear-of-house project rather than the terraced side-return infill that suits East Dulwich's closet-wing terraces, so we start from how the household actually cooks and gathers. The run of units, the island or table, the sightlines from cooking to garden and the circulation back into the existing house all set the plan before the footprint is drawn. A kitchen that works badly is a poor return on an expensive extension however generous its glazing, so the internal layout, not the outline, is where we begin and where the value of the project is won or lost.
Servicing is where a kitchen extension differs most from any other rear addition, and it is easy to underestimate. Moving the kitchen to the back of the house means relocating soil and waste drainage to reach the existing manholes, setting the falls that Building Regulations require, and planning the run for a sink, dishwasher and any utility fittings. Cooker extraction needs a ducted route out to an external wall or through the roof, gas and electrical supplies have to be extended safely to the new appliance positions, and those positions fix the plumbing before a single wall is built. We resolve the drainage strategy, the extraction route and the services layout at design stage, because retrofitting them around a finished room — chasing walls, lifting a new floor, re-routing a soil pipe — is where cost, delay and disruption tend to escalate.
Daylight is the reason a kitchen extension is worth doing, and in a deep plan it is a genuine technical problem rather than a given. When a single-storey addition projects into the garden, the back of the original house can be left darker than before, so we bring light in from above as well as through the garden wall — rooflights over the cooking zone, a glazed lantern over the dining table, or a fully glazed rear with sliding or folding doors. Each option is weighed for how far the light actually reaches into the plan and how the room reads from the garden and from the original house behind it, so the finished diner is bright at its centre rather than only along its glazed edge with a shadowed core.
The counterpart to all that glazing is overheating, a real technical constraint on this kind of stock and one that current Building Regulations now test directly. A south or west-facing kitchen-diner with a large lantern and full-height doors can become uncomfortable in summer without mitigation, so we balance the glass with solar-control specification, orientation-appropriate shading or overhang, opening lights for cross-ventilation and the room's thermal mass. There is a real tension here with the daylight ambition, and resolving it is part of the design rather than an afterthought. Getting it right on the drawings keeps the space usable year-round and satisfies the overheating assessment that Building Regulations require, rather than leaving the owner to fit blinds, external shading and fans against a problem the glazing created and then live with for the life of the room.
Foundations deserve early thought because Dulwich's generous garden plots — particularly the villa gardens near Dulwich Park and the deeper semi-detached plots — often carry mature trees, and tree roots are a recognised technical constraint on this kind of plot. Building near a tree can require deeper foundations or a specific foundation type to manage seasonal ground movement where the subsoil is shrinkable clay, and existing drainage runs near roots have to be worked around rather than cut through. These decisions change both the cost and the buildability of a rear kitchen extension, and they interact with the drainage strategy, so we identify significant trees, their root protection areas and the drainage positions during survey rather than discovering them when the ground is opened and trial holes are dug on site.
From there the route is a coordinated one. We survey the house and garden, test the kitchen-diner against the planning, conservation and — where it applies — Dulwich Estate consent position, then develop a design a Southwark case officer can support before producing the planning drawings and, once the principle is settled, the building-regulations package covering structure, drainage, ventilation, insulation and the overheating assessment. Because a rear extension usually sits close to a boundary and excavates near a neighbour's structure, the Party Wall etc. Act 1996 typically applies, so we identify notifiable neighbours early and coordinate the notices with the build programme. The result is a kitchen extension that works as a room, holds its daylight and comfort, and adds space that the household uses every day rather than simply added floor area on a drawing.
