Six metres between two gable walls. A lock-up garage at the back, a passage you couldn't get a skip down, and a yard that sees direct sun for about forty minutes in June. No view worth the word. No landscape. Nothing across the street except more of the same brick.
You can still do the sun path. It will be geometrically correct and completely useless, because the thing controlling light on this plot isn't the sun's altitude in March, it's the three-storey flank wall eight metres to the south. The template you learned on a generous site assumes the site has a relationship with something distant. An infill plot doesn't. Its entire context is within touching distance, and most of it is owned by somebody else.
So change the questions. On a constrained site the analysis that earns its place is about adjacency, legality and buildability — what the neighbours are entitled to, what you're allowed to touch, and how a building physically arrives on a plot you can barely walk round. Seven constraints, each with something specific to record while you're standing there, and each with a design consequence you can draw.
1. The Neighbour's Windows Are Part of Your Site Boundary
On a rural site, daylight analysis is about your own rooms. Here, it's about theirs first. Every habitable window looking onto your plot is a potential objection and, if it's old enough, a potential legal right — under the Prescription Act 1832, light enjoyed uninterrupted for twenty years can become an easement, and that is a different and more serious animal than a planning objection.
Record on site: photograph and locate every window on every elevation facing your plot. Cill heights above your ground level, rough widths, and your best guess at what room is behind each one. A bathroom with obscure glazing is not a habitable room; a kitchen window is. Note which ones are the only window serving a room, because those are the ones that hurt. Measure the distance from each to your boundary with a tape, off the boundary fence, and take a photo with the tape in it.
How it converts: the BRE's guide Site Layout Planning for Daylight and Sunlight gives you the tests councils actually apply — the 25-degree section test from the centre of the neighbour's window, and the vertical sky component check where that's breached. Draw that 25-degree line on a section through your plot before you draw a single plan. It gives you a sloping ceiling to your massing on that side, which is usually where the top-floor setback, the mansard, or the pitched roof with the ridge pushed off-centre comes from. The constraint isn't a restriction on the design. It is the design.
2. Draw the Party Wall Line Before You Draw the Plan
On a terraced gap site you are almost certainly building off, against or near somebody's wall, and the Party Wall etc. Act 1996 decides how much freedom you have. Section 6 catches excavation within three metres of a neighbouring structure where you go deeper than their foundations, and within six metres where a 45-degree line from the bottom of their footing would cut your excavation. Both distances change what's viable — not whether you need a notice, but whether you can have a basement, a deep pad foundation, or a piled solution at all.
Record on site: which walls are yours, which are shared, which are the neighbour's standing entirely on their land. Look for the giveaways — a flank wall with no openings and a weathered brick arris sitting exactly on the line, old joist pockets, a straight vertical joint where a previous building was demolished. Photograph existing cracking and movement before you go anywhere near a design, because you'll want that record later. If there's an inspection chamber or an old cellar light, note it.
How it converts: the party wall line sets your structural grid and your construction sequence. If you can't underpin economically, your floor level is fixed near existing ground, which cascades into thresholds, drainage and whether you get a double-height space. And if the adjoining owner's wall is the one you were planning to build against, the notice period is in your programme whether you like it or not.
3. Everyone Can See You
Overlooking is the reason most backland schemes get refused, and it's a geometry problem you can solve on a plan with a protractor before an officer ever raises it.
Record on site: stand where you think the main living space will be and look up. Photograph every window and every roof terrace that can see that point. Then do it the other way — go to the boundary and work out what your windows will see. Rear dormer windows are the ones people miss, because they're invisible from the street and lethal in an objection letter.
How it converts: draw the cones of view onto your plan as hatched zones and place your openings outside them. Some local plans carry a back-to-back separation distance; that's a local policy number rather than a national one, so read the one that applies to your borough rather than repeating whatever figure you heard in studio. Where the geometry refuses to work, you get high-level glazing, rooflights, clerestories above sightline, obscured panels to circulation and a courtyard that borrows light without borrowing views. That is a genuine architectural strategy, not a compromise — the inward-facing plan is what constrained sites have always produced, from Roman atrium houses to Sergison Bates' infill terraces.
4. Somebody Has to Drag the Bins
Refuse and cycle storage kills more small urban schemes at validation stage than anyone admits, because it eats the exact piece of ground you wanted for an entrance.
Record on site: where do the neighbours' bins go out, and where does the lorry actually stop? Walk the route with your phone timer. Note the gradient, any steps, gate widths, and whether the passage is shared with a right of way. Find your local authority's waste and recycling guidance for new development — it will state a maximum carry distance from storage to collection point, and it varies by borough.
How it converts: bin and cycle store are the first two boxes you place on the plan, not the last. On a narrow plot they usually decide which side the front door goes, whether you get a recessed entrance, and how much frontage is left for a window. Put them in at the start and your ground floor is honest. Put them in at the end and you lose a room.
5. How Does the Building Physically Arrive?
This is the constraint nobody teaches and every contractor asks about first. A plot you can only reach through a 900mm passage cannot be built the way a plot with a driveway can.
Record on site: the width and headroom of every route onto the plot. The carriageway width outside and whether parking is controlled. Overhead cables and tree canopies. Whether a crane could stand in the street, and what it would have to oversail — because oversailing a neighbour's airspace needs their agreement, not just the council's. Is there room for a skip, a welfare unit, a material drop? Photograph the pinch point with a person in shot for scale.
How it converts: straight into structural strategy and component size. If nothing longer than 2.4m gets in, you're looking at timber frame in panels, or blockwork, or a steel frame in short bolted sections rather than one long beam. If there's no crane standing room, the design that needed a 9m transfer beam is dead. Thinking about this at concept stage is the difference between a scheme that gets built and one that gets value-engineered into something you don't recognise.
6. Follow the Water
Record on site: lift every manhole cover you can safely lift, in the plot and in the street. Note the direction of flow, whether it's foul, surface water or combined, and take a rough invert depth with a tape and a torch. Photograph it. Check the water company's sewer records for anything running under the plot, because building over a public sewer needs a build-over agreement and can move a whole footprint sideways. Look at the fall of the ground, and at where surface water currently ponds — infill plots are often the bit of the block nobody built on for a reason.
How it converts: invert levels set your lowest possible finished floor level. That determines whether a sunken courtyard or lower-ground room is achievable by gravity or needs a pump, and pumps are a maintenance conversation clients hate. Combined with the party wall depth constraint, drainage usually settles your section before your plan.
7. Read the Refusals Next Door
The best-value hour of research on any infill site is free and done at a desk. Your council's planning portal holds every application on every adjoining address, including the ones that failed.
Record: search the neighbouring addresses and the whole block. Download the officer reports — not just the decision notices — for anything refused in the last decade, and any appeal decisions from the Planning Inspectorate. Note the exact wording of the refusal reasons. If two backland schemes on your street were refused for overlooking and loss of outlook, you now know the specific thresholds this authority applies, in their own language, with the evidence they weighed. Approvals are just as useful: a granted scheme next door is a precedent you can name in your design and access statement.
While you're in the archive, pull historic OS maps. They'll often show the original plot line, a building that was bombed or cleared, or a yard use that tells you something about what's in the ground. On a site with no visible history, the map is the context.
What a Tutor Actually Wants to See When There's Nothing to Draw
The fear on a site like this is that the analysis board will look empty. It won't, if you've stopped drawing the things that aren't there and started drawing the things that are.
What reads well is close-range and specific: a section with the neighbour's window and the 25-degree line on it. An overlooking plan with view cones. A delivery-route axonometric. Three manhole covers with inverts. A page of refusal reasons from next door, quoted. That's a scheme with an argument behind every move, and it beats a beautifully rendered 500m catchment map that proves only that you can operate a GIS plugin. If you want the graphic craft of getting that onto a board, we've written about turning site analysis findings into diagrams that read on a crit board separately — but the content has to be there first.
And record what you can't photograph. Which end of the plot is quiet. Where the traffic noise reflects off the flank wall. Whether the yard smells of the restaurant extract two doors down at six in the evening. Where the one patch of sun lands at four o'clock and for how long. That last one is worth two visits at different times of day, and it's usually the thing the finished building is organised around.
No View Is a Brief
The instinct on a plot like this is to treat the absence of context as a deficiency — something to apologise for in the first line of the report. Don't. A site with no outlook is a site that tells you exactly where the light has to come from and exactly where the building has to look. Inward. Upward. At itself.
What we've found teaching this is that the students who freeze are the ones still looking for something picturesque to respond to, and the ones who fly are the ones who accept that the party wall, the bin route, the neighbour's kitchen window and the sewer invert are the context. All seven of those constraints are conversations with somebody else — a neighbour, an officer, a contractor, a water company. Have them early, on paper, and the design that survives them is usually better than the one you'd have drawn on an empty field.
