If you scroll through London Design & Build’s project gallery, you’ll notice something most extension photos don’t bother showing you: proper before-and-after pairs, side by side, on the same house. Not a glossy render next to a finished shot — an actual “here’s what it looked like” next to “here’s what it looks like now.” That’s a small thing, but it tells you something about how the company thinks about this work: the goal isn’t just adding square footage, it’s making sure the extension feels like it was always meant to be there.
That’s a harder thing to achieve than it sounds, and it’s a big part of why the design and build model exists in the first place — particularly for something as structurally involved as a double storey extension.
It’s Not Just a Bigger Single Storey Extension
A lot of homeowners think of a double storey extension as simply “the single storey option, but taller.” Structurally, that’s not really true. You’re loading two floors at once rather than one, tying new brickwork and steelwork into the existing house at multiple points, and in most cases removing at least one internal wall downstairs to get that open, connected living space people actually want. Every one of those decisions needs to be right from the start, because mistakes here don’t stay small — they ripple through the whole design.
Where Fragmented Projects Fall Down
The traditional route is still common: hire an architect, then separately find a structural engineer, then separately find a builder. It can work, but it leaves a lot of room for things to not quite line up. An architect draws something without necessarily knowing what a structural engineer will say about it. The engineer, brought in afterward, might require more steel than the design allowed for, changing ceiling heights or costs nobody budgeted for. By the time a builder prices the final version, it’s often a different project to the one the homeowner fell in love with at the first meeting.
A joined-up team removes most of that risk, because the same people responsible for the design also have to make it work on-site — so buildability gets factored in from the very first sketch, not discovered three revisions later.
How London Design & Build Actually Approaches This
Looking at how the company describes its own double storey projects, a few things stand out. They talk specifically about making sure an extension “feels like a natural part of your home, not an add-on” — with materials, proportions, and overall style planned to blend with the existing house rather than standing apart from it. That’s a genuinely different design brief to “just build the extra space,” and it’s the kind of detail that only really gets addressed properly when architects and builders are working from the same brief throughout.
They also make a specific point about their process starting with feasibility and site assessment before any serious design work happens, so what gets drawn is grounded in what the actual property and plot can support — not redrawn later once someone discovers a problem.
Two Things They Call Out Specifically: Communication and Quality
On their site, London Design & Build singles out two commitments that go beyond the technical side of the build. The first is communication — every client gets a dedicated project manager who provides clear updates throughout, so you always know what’s happening rather than guessing based on noise from the garden. The second is quality — using materials and craftsmanship built to last and genuinely impress, not just meet minimum standard.
Those two things matter more on a double storey extension than a smaller project, simply because the build takes longer, involves more trades, and the finished result is more visible and permanent in how it changes the house.
The “LDB Difference”: Price, Transparency, Reliability
The company frames its approach around three specific commitments: price, transparency, and reliability. On price, their stated position is that once a contract is agreed, they stick to it, keeping the project on budget without cutting corners. On transparency, they commit to no hidden costs and no last-minute surprises on pricing, timelines, or design choices. On reliability, the promise is delivering on time and on the original agreement, handling details with care to keep the process smooth.
Whether any company lives up to commitments like these is obviously something you judge by asking previous clients and reviewing actual project outcomes — which is exactly why a project gallery with real addresses and real case studies, rather than stock photography, is worth paying attention to when you’re comparing options.
Planning Permission Still Needs Proper Handling
Regardless of who you build with, a large proportion of London extensions require planning permission, and a meaningful share of applications get rejected when they’re submitted without expert guidance behind them. Building regulations approval is needed for the vast majority of extension work too, separate from planning. A double storey extension specifically tends to draw more scrutiny than a single storey one, given its greater impact on a neighbour’s light and the overall street scene, so local knowledge of how a specific council tends to respond genuinely matters.
Structural Engineering Isn’t Optional Here
Wall removals and multi-storey loading both require proper structural calculations as standard — not a guess, not something to sort out once building control asks questions. Having structural engineers genuinely embedded in the design process from day one, rather than reviewing someone else’s finished drawings afterward, is what catches problems while they’re still cheap and easy to fix on paper.
In Conclusion
A double storey extension is one of the more significant structural and financial commitments a London homeowner can make to their property, and the difference between a joined-up design and build team and a fragmented one shows up most clearly on projects exactly this size. London Design & Build offer a free site visit to talk through what’s genuinely achievable for your property if you’re considering a double storey extension. Get in touch and see their project gallery for yourself before deciding what’s right for your home.
