Hot2000 is a tool used by energy advisors in Canada to help homeowners make decisions on energy retrofits and qualify for federal incentives. However, this tool is only available for Windows. As a Mac user, I saw the need to build a tool that allows people without Windows PCs to run their Hot2000 (.h2k) files quickly. Without knowing how to define success for this project, I wanted to build something quick, small and simple and put it out in the world.

Simple UX experience for the web.

When running the h2k files the modelling results are captured in the HOT2000 generated report. The reports are generated as HTML files, making it easy to share the results on the web. Therefore, the simplest approach I could think of is to upload file -> download report.

Building the tool

I began building the tool in January 2024 and had a working version by March of the same year. Since I had to take full-time care responsibilities for my one-year-old, I worked on this tool one day a week for a few hours. The web tool was made using a simple stack (Ubuntu, Flask, Python, HTML, Javascript). A Windows worker bot made with Python periodically checks the server where the web tool is hosted. Once a new file has been detected, the bot downloads the files, runs the file in HOT2000, stores the report and uploads those back to the server.

Launch 🚀

I made a post on the Energy Advisors board on Reddit, which has received about 691 views as of now. I also posted it on LinkedIn, but it got less traction with only 191 impressions, at the time of writing this post. After being publicly available for six days, we have received four file uploads to the service. Two successfully were run by the workbot resulting in a report for download. In two cases the worked but failed to generate a report. I will provide more details about this later.


On the Reddit post, I received feedback on the tool which was positive. I saw that there were two concerns one with privacy and another relating to the legality of using HOT2000 for this tool.

  • Addressing the privacy;
  • My sense is that the user who highlighted this thinks that the information in the h2k file is sensitive (debatable). However, that being said, I do agree we would like to make sure any information that is generated should be distributed to the user submitting the file. The only way you can find the resulting report is by having the link. This link is created using an encryption technique which is impossible to backward engineer. This makes it impossible to guess and is standard practice in sharing sensitive information (like Google Docs share links for example).
  • There are many other precautions I have taken to protect passwords, server access, and Windows bot. I won’t go into great detail, however, the practises I use are standard in the security community.
  • HOT2000 licensing information
  • My reading of the licensing information doesn’t exclude the use of this software in this way. That being said, I’m giving people access to the “public” version of HOT2000. Giving more people access to this tool, outside Windows users, is in the spirit of what this “public” version stands for. My sense is that whether you like it or not many users may have linux systems, and or Mac systems. These systems are barred from using this software that is required by the government to be used for energy audits etc.

Issues we ran into

As stated above we saw that we had a 50% success rate on generating the report. I anticipated that people may upload older files, and the worker bot can upgrade old files. However three issues I ran into were unforseen:

    1. If the file is referencing a “reference house file” we have to use the “base reference house.” This causes the bot to fail, and setting it to the base house may cause different energy modelling results. Right now, we are setting the base house, but we might want to track down how to get these reference houses.
    1. An issue with the design of the file. HOT2000 can do a quick check on the files to see if it makes sense. I’m not sure how to deal with the specific building design issues that the software raises, but I sense that the best UX experience is to let people know that there was an issue and that they should fix the h2k file themselves.
    1. Wrong units in the report. One user reported that the heat loss was in weird units. This is a bug in the latest version of HOT2000. I sense that we should give people the option to select which version they want to use, while also selecting the default version to be the older version of HOT2000 which does not have this issue.

Defining Success and next steps?

Within two months we had a working version of HOT2000 on the web. And, if you make a file in HOT2000 that runs, without the use of reference buildings it seems to work fine.

We got valuable learnings from this one-week experiment. And some clear next steps to continue this work:

  • My sense is that I’d like to make the bot better to deal with the issue above and report any issues it can’t fix back to the user on the page of their unique link. And, if we upgraded the file, or set the file to the base reference building, it would be stated on this page (estimated time 20hrs).
  • I’d also like to give the user the ability to select a version of HOT2000 (estimated time 6 hrs),
  • Report the issue to NRCan that I found in the latest version of HOT2000. (estimated time 30 min).
  • Lastly, what I’d like to do is add a “delete this file” button. This way users can generate the report, download it, and delete it afterwards (estimated time 3 hrs).

In the next version that I release, I’d like to define the following success metrics. What I’d like to shoot for in the next release; With the new bot I’d like to see after 100 files we see 80% of all files have a report and, 90% of the failures are correctly reported to the user.

Given the time estimates and my budget of 3 hrs a week, the total effort estimation should be approximately 10.3 weeks (5% additional budget). Based on the start time of this project next week, the estimated time of completion will be to release of new version of the tool in the third week of July.

Given that most of the time would be in work on the bot, I will leave that last, and work up to it making the other features first.