I gave myself three months. Drawings, planning, done, building by summer. That timeline now makes me laugh. The reality of architectural services in London ran on a completely different clock, and nobody had set my expectations properly until I was already in it.
When I signed up for architectural services london, I thought the slow part would be the building. Actually the design and approval stages took far longer than I imagined, and the building was the quick bit at the end. I had the whole thing backwards in my head.
The architect was upfront once I asked directly. She said most of the time goes before a single brick is laid. Design, revisions, planning, party walls, building regs. I just hadn’t understood that when I set my hopeful little three month plan.
Why the Design Stage Takes So Long
I thought design was a week of drawing. It was more like two months. Not because anyone was slow, but because good design is iterative.
We went back and forth. First sketches, my feedback, revisions, a 3D model, more feedback. Each round improved it, but each round took time. Rushing it would have meant building the wrong thing.
The architect offered unlimited amendments at the design stage, which sounded generous until I realised how many we actually used. That patience is what got the design right. It just isn’t fast.
The Planning Wait Nobody Speeds Up
Once the design was settled, the planning application went in. Then we waited. And waited. The council has a statutory period of around eight weeks, and they use most of it.
There is no shortcut here. No architect, however good, can make the council decide faster. What a good one does is make sure the application is strong enough to be approved first time, so you don’t go round again.
Ours had designed to what our borough approves, so we got a yes on the first attempt. That was the real time saving. A refusal would have added months, not weeks.
Party Walls and Other Hidden Delays
Then came the party wall process, which I had never heard of. On our terrace we had to notify neighbours on both sides and wait for their responses.
One neighbour consented quickly. The other took weeks and eventually needed a surveyor to sort an agreement. That alone added the better part of two months to the timeline.
None of this is the architects fault, and a good one runs these processes in parallel where possible. But you cannot skip them, and they eat time you didn’t budget for.
What Actually Moved Quickly
Here is the irony. The building itself, the bit I had braced for, went relatively fast. Because the drawings were detailed and the planning was sorted, the builder just got on with it.
A straightforward loft conversion or rear extension can be built in a few months once everything is in place. The construction is the visible, satisfying part, and it rarely drags if the prep was done properly.
All that slow design and approval work upfront is what makes the build quick and smooth. I had resented the early delays. By the end I understood they were buying me a clean construction stage.
Setting Realistic Expectations
If I did it again, I would plan for the whole thing taking the best part of a year, not a season. Design two months, planning two to three months, party walls overlapping, then a few months to build.
That sounds long, but it is normal for a proper London project done well. The people who get burned are the ones who, like me, assume it will be quick and then panic at every delay.
A good architect tells you this at the start. Mine did, the moment I asked. I just wish I had asked before setting my own fantasy timeline.
What to Ask About Timing Upfront
Ask for a realistic timeline broken into stages, not just a total. You want to see how long design, planning, and party walls each take.
Ask what could cause delays specific to your project. Conservation status, awkward neighbours, shared drains all add time, and a local architect knows which apply to you.
Six to eight months from first meeting to a finished extension, and most of that was before the build even started. The architectural services weren’t slow. My expectations were just wrong. Once I understood where the time actually goes, the whole process felt far less stressful.