In most London renovations, the garden is the last conversation — not the first. The architect designs the extension. The builder constructs it. And months later, once the dust has settled and the budget has recovered, a garden designer is brought in to work with whatever space and conditions remain.
By that point, the most important decisions have already been made — floor levels, threshold details, glazing positions, drainage routes — without the garden in mind. The result is a home where inside and outside feel like separate projects, because they were.
It does not have to work this way.
What Goes Wrong When the Garden Comes Last
The problems are specific and, for anyone who has lived through a renovation, likely familiar.
Thresholds that lock out a flush connection. Modern sliding doors are fitted with integrated drainage upstands — a small protective shelf at the base that prevents rainwater ingress. Once the door has been specified and installed without the garden designer’s involvement, that shelf physically prevents the patio from being laid level with the interior floor. The seamless indoor-outdoor threshold — the detail most homeowners dream of when commissioning a rear extension — has been designed out of the project before the landscaper ever walks on site. This kind of integration is achievable when doors are specified with the landscape in mind from the start, but becomes impossible as a retrofit.
Floor levels that create awkward steps. Extension slab levels are typically set to match the existing house — but the garden often sits considerably lower. Without early coordination between architect and garden designer, homeowners inherit oversized steps or retaining walls eating into an already compact London garden. In many boroughs, raising external ground levels beyond a certain threshold can itself trigger a planning requirement, which means the problem cannot simply be solved by importing soil after the build.
Glazing that overheats. A south-facing glass extension looks beautiful in the architect’s renders. In July, without external shading or considered planting, it can become unusable. Overheating in single-storey rear extensions is now one of the most commonly documented comfort failures in London residential architecture. Deciduous trees positioned to shade summer glazing while admitting winter light are among the most effective passive cooling strategies available — but their position needs to be planned alongside the extension, not planted as a remedy years later. On east- and west-facing elevations, where the sun sits low and architectural overhangs alone are insufficient, strategically placed planting is often the only practical solution.
Side access lost to the build. Side-return extensions — among the most popular projects for London terraces — routinely close off the only route by which garden materials, mature specimen trees, or machinery can reach the rear garden. A decision made for the building has, without anyone noticing, limited what the garden can ever become. Had the garden designer been consulted at concept stage, that access constraint would have been flagged before any planning application was submitted.
These are not failures of garden design. They are failures of sequencing — decisions made in isolation that could have been resolved in the first weeks of the project.
What Changes When the Garden Is Part of the Brief
The alternative is straightforward: include the garden in the architectural brief from the very first stage.
This means the architect considers the garden relationship when positioning the extension — where glazing frames planting, where the threshold sits, how the building footprint preserves the most useful outdoor space. It means floor levels, drainage, and material transitions are resolved on paper during the concept phase, not improvised on site months later. It means the garden designer sees the layout plans, understands the interior material palette, and knows where the key views fall — before any planning application is submitted.
The RIBA Plan of Work — the industry-standard framework for managing building projects — explicitly anticipates this. Its guidance for Stage 1 recommends considering whether landscape consultants should be appointed alongside the architect from the outset. The Landscape Institute advocates the same early engagement. Yet in most residential projects, the garden designer’s appointment still comes after the building is complete.
When the sequence is corrected, the outcomes are tangibly different. A patio that sits flush with the kitchen floor because the threshold was specified with both sides in mind. Planting that frames the view from the dining table because the window position and the planting scheme were developed in the same conversation. Materials that flow from inside to outside because one team was thinking about both. For a deeper look at how this connection plays out in rear extension design, read Where Home Meets Garden.
The Garden as Environmental Infrastructure
There is a practical argument here that goes beyond aesthetics. The garden is the largest piece of passive environmental infrastructure on the average London plot.
Research on common UK tree species has found that mature canopies can reduce surface temperatures beneath them by an average of 12°C — shading glazed rooms at exactly the time of year when overheating is most acute. Deciduous trees allow solar gain through in winter, when it is needed. Evergreen boundary planting provides wind protection and visual screening year-round. Permeable surfaces and considered planting attenuate rainwater runoff, reducing pressure on drainage systems that are increasingly strained by heavier rainfall.
These are not decorative decisions. They are building performance decisions — and they need to be made at the same time as the glazing specification and the extension orientation. An architect designing a rear extension without understanding what will be planted outside is, in effect, designing half a thermal strategy. As summers grow hotter and London homes increasingly face overheating risk, the garden’s role shifts from ornamental to essential. We explored this broader shift in our article Designing for Climate Change.
One Vision, One Brief
At YKD, we design architecture, interiors, and garden under one guiding vision from the very first stage. The garden designer is part of the concept conversation — seeing the layout plans, understanding the interior material palette, and knowing where the key views fall — before any planning application is submitted. Their planting scheme responds to the architecture, and the architecture has already been shaped with the garden in mind.
This is what makes integrated design different from commissioning three separate professionals in sequence. When one studio holds the brief, every decision — from floor levels to planting positions, from threshold details to material transitions — is made in the same conversation, not reconciled after the fact.
The difference between a home that feels assembled from parts and one that feels whole almost always comes down to whether these conversations happened together or apart. We wrote about this broader pattern of fragmented decision-making — and why it matters — in The Biggest Mistake Homeowners Make Early On.
One Thought, Not Three
A garden is not a finishing touch. It is part of how a home breathes, how light enters, how the seasons are felt. When it is included in the architectural vision from the very beginning — not as an afterthought, but as an equal consideration — the result is a home where inside and outside feel like one continuous experience.
At YKD, the garden is part of the brief from Stage 1 — because a home should feel like one thought, not three.
Image credits: Studio Bright, MATA Architects, Lucas, HA Architecture, Shed, Clare Cousins Architects
