How to Check UK Planning Constraints Inside Autodesk Forma Site Design

Forma Site Design's automated context for the UK covers terrain, building footprints and heights, roads and property boundaries, plus weather data for its environmental analyses. That is enough to test massing options and compare sun hours, wind comfort and noise while the design is still fluid.

Planning constraints are a different class of evidence. Flood zones come from the Environment Agency's Flood Map for Planning. Conservation areas, Article 4 direction areas, Tree Preservation Orders and national environmental designations are published by councils and Natural England through planning.data.gov.uk. Listed buildings sit on Historic England's National Heritage List. Ground movement risk comes from the British Geological Survey's GeoSure data. None of these arrive with the Forma site by default, and stitching them together by hand takes an afternoon that most early-stage budgets do not have.

The Atlasly extension does that stitching for the site limit you have already drawn, and keeps each answer tied to its source so it can be checked.

Open a project in Forma Site Design and select Extensions in the left panel, then Add extension. Extensions that have not yet been published to Autodesk's Marketplace are shared by ID and installed from the Unpublished tab: paste the Atlasly extension ID, select Add, then Agree to the terms. Extensions install per project, so repeat this for each project where you want the panel.

Once installed, Atlasly appears in the Extensions tab of the left panel. Draw or select a site limit before opening it; without one the panel falls back to the project location and says so.

The panel needs no Atlasly account. It uses Atlasly's public site tools, the same ones exposed to Claude, ChatGPT and other assistants through the hosted MCP endpoint.

If a site limit is already drawn, the check runs the moment the panel opens. Otherwise choose a search radius of 250, 500 or 1,000 metres and select Check constraints. The panel retrieves eight official sources live, which usually takes fifteen to forty seconds, and shows an elapsed timer while it works.

The result opens with a verdict line, for example 5 of 8 need attention, followed by chips for high, check, none found and no data, and then the read: one sentence naming what consent will turn on, the likely consent route, and the statutory notes that follow from it. Below that a site map draws the search radius, your site limit and the evidence layers in their own colours; a legend toggles each layer, and a layer that blankets the whole frame, such as a city-wide Article 4 area, is drawn as a dashed outline so it does not hide the rest.

The ledger lists each constraint with a short value, a planning implication and, where you drew a site limit, how the evidence relates to it. That relation is measured rather than described: a layer that overlaps your boundary reports the share it covers, such as covers 41% of your site, sampled on a regular grid across the boundary. A layer outside the boundary reports the distance to its nearest edge. Expanding a row shows the evidence text, any coverage caveat, the source records and the retrieval date.

Flood Zone 3 means a flood risk assessment is required and the sequential test applies; for more vulnerable uses the exception test may apply too. Flood Zone 2 also requires a flood risk assessment. Zone 1 is the lowest fluvial and tidal probability but says nothing about surface water, which the panel reports separately when the source answers.

A conservation area brings design, demolition and tree-works controls and usually a heritage statement. Listed buildings nearby make the setting of heritage assets a material consideration, and Grade I or II* assets raise the bar. An Article 4 direction withdraws some permitted development rights; the council text says which classes. Tree Preservation Orders mean works to protected trees need consent, but many councils have not yet published their orders to the national dataset, so the panel reports no data rather than none, and points you to the council register.

National environmental designations trigger ecological assessment and consultation. Registered historic landfill within the radius calls for a contamination desk study. A BGS shrink-swell class of 3 or higher points to a ground investigation and engineered foundations.

A constraints list describes the site. The question a designer actually has is what it does to the scheme, and Forma is the one place where both halves are present at once.

The panel reads the masses in your proposal and reports three things: how much of the built footprint sits inside each flagged constraint, the height of the tallest mass, and the share of the site limit you have covered. It is stated the way a designer would say it, for example 62% of your built footprint sits inside conservation areas, alongside 4 masses, 2,140 m² of footprint, tallest 24 m, covering 43% of the site limit.

That read is recalculated whenever the model changes, using the evidence already retrieved, so moving a block and seeing the exposure change costs nothing and needs no second check. Heights are measured from each mass's own base, so they describe the massing rather than an absolute datum.

The findings imply a scope of work, and the panel writes it out rather than leaving it to be inferred. Flood Zone 2 or 3 means a flood risk assessment and the sequential test. A conservation area or nearby designated assets means a heritage statement and an assessment of significance. A Tree Preservation Order means a tree survey and an arboricultural impact assessment to BS 5837. A national environmental designation means a preliminary ecological appraisal. Registered historic landfill means a Phase 1 contaminated land desk study. A BGS shrink-swell class of 3 or higher means a ground investigation before foundation design.

One item is always on the list and never appears in a constraints dataset: 10% biodiversity net gain, which is mandatory for most new development in England, with householder, self-build and de minimis schemes the exceptions.

Each line names the evidence that put it there, which is what makes the list defensible in a fee proposal rather than a generic checklist. It is a scope to confirm with the planning authority, not a determination.

Copy appraisal puts the whole thing on the clipboard as formatted text: the read, the consent route, the scope, the massing implications, then every finding with its source and retrieval date and the screening caveat. It pastes into a feasibility report, a design and access statement or a pre-application enquiry without reformatting.

Copy share link produces a URL that reopens the same check, against the same red line, in any browser. The recipient needs no Atlasly account and no Forma seat, which makes it the quickest way to put the evidence in front of a client, a planning consultant or a colleague. The evidence is retrieved live each time the link is opened, so the page reflects the day it is read rather than the day it was sent, and it says so.

If Forma's panel blocks clipboard access, the panel falls back to a selectable text box rather than failing silently.

The panel ends with the questions this particular check left open, each opening Atlas AI with the question ready to run. They follow the findings rather than a fixed list: a site in a flood zone is asked whether it passes the sequential test, a site in a conservation area is asked what has actually been approved there and at what height, a site under an Article 4 direction is asked which permitted development rights are left. Alongside them sit the local plan policies for the authority, cited by paragraph, and the full site package with DXF, DWG and IFC exports for Revit.

Each of those links carries the boundary you drew in Forma, so Atlasly opens on your red line and draws it on the map instead of reverse-geocoding an address to a point. Planning history, precedents and policy answers are then specific to the site rather than to a pin near it.

The site package is the handover artefact. Its DXF carries the constraint boundaries, contours and surrounding buildings on named layers, and imports into Revit through Insert and Import CAD in metres. Your Forma massing reaches Revit through the Forma Connected Client as usual, so the constraint layers and the scheme meet in the same model. The Atlasly guide to exporting site analysis data to AutoCAD and Revit covers the import settings.

Saving the site to an Atlasly project also enables Site Watch, which re-runs the checks and flags changes in the planning record over time.

The underlying retrieval is a point-radius screen around the site centre, so it says whether evidence exists near the centre. The site-limit lines, coverage shares and footprint exposure are a planar check against the boundary you drew, not an official parcel intersection, and the shares are sampled on a regular grid, which makes them accurate to a few percent rather than surveyed. None of it replaces a planning search, a flood risk assessment or professional review.

Coverage is UK only: England in full, Scotland and Wales in part. Forma projects with another country code are declined before any check runs. Some sources time out on busy days; the panel then reports that fact for that source rather than guessing.

Inside the Forma scene, Autodesk's renderer draws overlay layers in a single style, so painted layers share one colour; the panel's own map is what separates them by colour. Overlays are visual only and are cleared by Forma when the panel closes.