Site analysis diagrams, England · Hobby project

UK Site Analysis

Pick a site anywhere in England and get fourteen site analysis diagrams, drawn to the same frame and scale: figure-ground, building heights, topography, sun and shadows on 21 March, June and December, sunlight hours, sky view factor, prevailing wind, access, road and rail noise, green and habitats, planning constraints, flood zones, a BRE 25° screening check and views. Buildings and heights come from Environment Agency LiDAR. Turn the site in 3D, pull the diagrams apart into an exploded axonometric, pick a colour style, and download an A3 or A2 board, square images, or DXF and SVG drawings in British National Grid for your CAD.

SitePostcode or place search, then your own drawn boundary or a radius

OutputA3 or A2 board (PDF) · PNG · 14 squares (ZIP) · exploded 3D view · DXF and SVG

CostFree, no sign-in, runs in your browser

Site

1. The site

Site area: -
Perimeter: -

2. The board Title on the board (optional) Frame (every diagram)

Colours Frame shape

The dashed square on the map is what every diagram will show.

The board

Your board of fourteen diagrams appears here after Analyse site.

Data: Environment Agency, MHCLG (planning.data.gov.uk), Defra, Natural England and DfT under the Open Government Licence v3.0; ERA5 wind via Open-Meteo (CC BY 4.0); search by postcodes.io (contains OS data © Crown copyright and database right); roads from OS Open Roads (contains OS data © Crown copyright and database right 2026); map and paths © OpenStreetMap contributors. Hobby project, not official, for reference only. Not a substitute for a survey or professional advice.

How to use it

Search a postcode, a town or a village, or click the map. You can also type coordinates (lat, lon or British National Grid E, N).
Set the site: pick Draw site boundary and click each corner of your site (click the first corner to close it, then drag corners to adjust), or pick Circle for a quick 25 to 200 m radius. Drag the dot to move the whole site.
Give the board a title if you like, leave the frame on Auto or pick a size, and pick a colour style and a square or round frame; both can change after the analysis.
Press Analyse site. The data loads live from government servers, usually in under half a minute. Then download the PDF, the PNG board, the fourteen squares, the exploded view, or DXF and SVG in British National Grid metres.

The fourteen diagrams

01 Figure-groundBuildings in black on white, and how much of the ground within the frame's radius they cover.
02 Building heightsEvery LiDAR block raised as a plan-oblique, shaded by height above ground, the three tallest labelled. Heights at half scale.
03 TopographyGround levels from the LiDAR terrain model with hill shading, contours in metres above Ordnance Datum, spot levels and the fall of the site.
04 Sun and shadowsShadows at 12:00 on 21 March, 21 June and 21 December, the three sun paths, and the share of the site in shade on each date.
05 Sunlight hoursHours of direct sun on open ground on 21 March as a colour map, with the site averages for March, June and December and the share of the site with two hours or more on 21 March.
06 Sky view factorHow much sky you see at head height across the frame, from 0 (enclosed) to 1 (open sky).
07 Prevailing windWind roses for the year and for summer from ten years of ERA5 reanalysis at 10 m.
08 Access and movementBus stops and rail, Underground, metro and tram entrances from NaPTAN, roads and street names from OS Open Roads, footpaths from OpenStreetMap when it answers, and 5 and 10 minute walks along those roads; if no road data loads, straight-line distances, labelled as such.
09 Road and rail noiseDefra's modelled noise, LAeq,16h by day and Lnight, road and rail combined, on a 10 m grid.
10 Green and habitatsTree canopy found in the LiDAR, and Natural England's priority habitats.
11 Planning constraintsConservation areas, listed buildings, scheduled monuments, registered parks and gardens, World Heritage Sites, green belt, National Landscapes and national parks, Article 4 directions and tree preservation orders. Where a council publishes nothing on planning.data.gov.uk, the diagram says so instead of reporting none.
12 Flood zonesFlood Zones 2 and 3 for rivers and the sea, and the share of the site in each.
13 BRE 25° screeningThe height above the site at which a new building would cut the 25° line from neighbouring facades that face the site, with windows assumed 2 m above ground. A screening check, not a daylight assessment.
14 Views and opennessHow far you see from the middle of the site at street level and from 30 m up, and the directions that stay open.

Limits

Every diagram is drawn only from data the tool loaded. If a server does not answer, or a layer has nothing near the site, the diagram says so in words instead of guessing. The tool covers England only, where the Environment Agency LiDAR exists.

Buildings are found in the LiDAR, not taken from a map: ground 2.5 m or more above the terrain model where the laser's first and last returns agree (a roof, not a tree). Joined buildings become one block; sheds, dense evergreen trees or vehicles can slip in, and small buildings or glass roofs can be missed. Checked against OS OpenMap Local buildings on 28 October 2026, the outlines overlap with an intersection over union of 0.77 in a Hertfordshire city centre and 0.62 in the village of Ashwell, where small and tree-covered buildings are harder to find. Heights are the 85th percentile of the roof surface, with a taller part such as a tower kept as its own block; roofs are drawn flat. The LiDAR survey dates vary from place to place, so recent buildings may be missing or demolished ones still shown.

Coordinates are British National Grid. Points from latitude and longitude (search results, planning data, the map) are converted with the standard Helmert transformation, good to a few metres, not the OSTN15 grid. Every diagram has grid north up; true north differs from grid north by up to about 3° across England and the board states it.

Sun positions use the NOAA equations at clock time (GMT, or BST in summer). Drawn shadows fall on a level plane at the site's mean ground; the share of the site in shade is a separate 3D sun-ray test. Sunlight hours and sky view count buildings and terrain, not trees, and treat the site as cleared. They are not a daylight or sunlight assessment to BRE BR 209 or any other standard.

The BRE 25° check assumes a window centre 2 m above ground on every neighbouring facade that faces the site square on, within 60 m. Real window positions, room uses and the rest of the BRE tests (vertical sky component, daylight distribution, sunlight) are not known or not run. It is a screening check only.

Wind is ERA5 reanalysis at 10 m on a grid of about 25 km, for open ground: not street-level wind and not a wind microclimate study. Noise is Defra's Round 4 strategic noise model for 2022, not a measurement, and levels below its mapped range show as blank. Flood zones are the copy on planning.data.gov.uk, which carries its own date; it covers rivers and the sea, not surface water or groundwater. Check the Environment Agency's current Flood Map for Planning before relying on it.

Planning data comes from planning.data.gov.uk, which collects it from Historic England, Natural England, the Environment Agency and each council. Coverage of council datasets (conservation areas, Article 4 directions, tree preservation orders, listed building outlines) varies; the diagram tells "none found here" apart from "this council publishes none" where it can. Always check with the local planning authority.

Transport stops come from a NaPTAN snapshot of 28 October 2026. Roads, street names and the walking network come from OS Open Roads (October 2026 release, shipped with the tool). Open Roads holds roads only, not footpaths, alleys or cut-throughs, and walks follow road centre lines, so real walks can be shorter. Footpaths and building names are added from OpenStreetMap through the public Overpass API only when it answers, which it often does not.

Hobby project, not official, for reference only. Not a substitute for a survey or professional advice.

Data and licence

Buildings, terrainLiDAR Composite DTM and First Return / Last Return DSM, 1 m, Environment Agency, Open Government Licence v3.0, loaded live by WCS
Planning, floodplanning.data.gov.uk, Ministry of Housing, Communities and Local Government, with data from Historic England, Natural England, the Environment Agency and local planning authorities; Open Government Licence v3.0
NoiseStrategic noise mapping Round 4 (2022), road and rail, Defra, Open Government Licence v3.0
TransportNaPTAN, Department for Transport, Open Government Licence v3.0, snapshot 28 Oct 2026 shipped with the tool
WindOpen-Meteo historical weather API, ERA5 reanalysis (Copernicus Climate Change Service), CC BY 4.0
Searchpostcodes.io, ONS Postcode Directory and OS Open Names: contains OS data © Crown copyright and database right; Royal Mail data © Royal Mail copyright and database right; ONS data © Crown copyright and database right (OS OpenData, Open Government Licence)
SunNOAA solar position equations, computed in your browser
3Dthree.js, MIT licence, loaded from jsDelivr

Contains public sector information licensed under the Open Government Licence v3.0. © Environment Agency copyright and/or database right 2026. Contains Natural England data © Natural England. Every board prints the full credits and the disclaimer, and the DXF and SVG files hold them as text. A free hobby tool, not professional advice, and not affiliated with any government body, Ordnance Survey, the BRE or OpenStreetMap.