Automate: so HEM is better AND faster than SAP.
The Home Energy Model (HEM) is a new methodology for modelling how UK homes use energy, and will be introduced with the upcoming Future Homes Standard (FHS). HEM uses more realistic half hourly calculations than current methodology SAP (Standard Assessment Procedure - a simple monthly estimate), which makes HEM more useful for designing homes that are comfortable, low cost and carbon.
We spoke to 100s of Domestic Energy Assessors over the last 2 years while we were building with HEM. They told us their SAP software required manual data entry, and had limited and flaky integrations to import data from CAD tools like Sketchup or Revit. Their building regulations work was time consuming and increasingly commoditised. Under this paradigm, HEM only added cost and complexity.
Assessors can use Vulcan's CAD import and visual editor to create a HEM assessment in minutes - a huge time saving from the hours it can take to manually enter and check data today. Vulcan's goal is to makes HEM fast and easy to use - so Assessors can drop SAP for good.
Ultimately, we want to automate Energy Assessor "data wrangling" work so they can spend more time helping their clients (housebuilders, homeowners, local authorities and others) make better decisions.
Our 4 Design Laws for Automation
We're thinking very deliberately about automation of HEM workflows.
Law 1: Deterministic first
Enabling our users to import files from CAD programmes is important for productivity - but CAD inputs can be ambiguous.
Deterministic automation using geometric heuristics enables more reliable workflow integration. For example users can choose to enable use of a 3D representation of negative space for a one-shot HEM import. Users that build a CAD workflow around HEM can benefit from this.
With more cleanup, users can import external massings (enabling shared inputs with PHPP) or detailed geometric meshes from a housebuilder Revit model. More complex shapes can be delayered, trimmed, merged or snipped on import using defined rules, or precisely edited later in the user interface.
Law 2: Catch mistakes early
Vulcan use the official HEM schema to validate simulation inputs, but this is permissive and allows inaccuracies. This is why we enhance visual cues to surface mistakes early, for accurate HEM inputs with less work.
Visual data entry ensures Vulcan's users can quick validate and correct inputs. We show 'critical' flags when information is missing to run a HEM model, and 'warning' flags for unexpected inputs such as walls that don't add up or connect. Users can batch fixes to building elements.
Law 3: Humans in Control
We recently introduced AI (LLMs) into Vulcan to explain how to use HEM and work with Vulcan. Our model reference embeddings containing HEM's technical documentation and schema, plus Vulcan's operating handbook. Customers can see references to these sources and directly access them. Our AI's home is a chat interface that allows users to speak directly to the Vulcan team in-app. This means customers can choose if they work with human or AI support, and means Vulcan can help its customers make the most of their AI use.
We are designing workflows to utilise AI for tool use (both in-app and via MCP). We believe a human with good UX is faster and more precise at common tasks than a non-deterministic agent - but agents show promise for longer running or repetitive tasks. Agent-appropriate energy modelling tasks can include input validation and fixes, or setting up and analysing scenarios as part of design optimisation. We want our customers to have control and be able to audit how agents solve problems.
Law 4: Local and Limitless
Vulcan uses local files, embeddings, and compute for simulations. At the same time, our software is easily accessible via modern browsers. This makes workflow integration easier through direct exposure of config files, removes storage or simulation limits, reduces latency, and respects privacy.
Energy Assessors, Join Vulcan
HEM doesn't have to be hard to use. We plan to make it faster and more useful than SAP, so you can switch fast.
So give us your ugliest CAD files and let us make your work easier. Join Vulcan.