We've got quite a lot to write about since our last update in January.

New fuel costs

We've updated the fuel costs in HRP to the ones published by BRE for rdSAP in January 2022. These are used for new assessments only. We don't retrospectively update the fuel costs in work-in-progress or completed assessments for data integrity reasons - you want to know the basis upon which calculations were made in the past.

We expect another update from BRE soon and we'll implement that when it comes out.

Cost rounding

In the measures list in the report or CSV 'scope of works' outputs, we are now rounding the costs on elements. Previously these were providing a misleading level of accuracy. If an individual measure's cost is under £500, we round up to the next £5; if it's under £5000, we round up to the next £50; and otherwise (when the cost is above £5000) we round up to the next £500 increment.

Reworked solar hot water view

Our newest software engineer Joe has been working on a new solar hot water calculation page. We've been using this page to experiment with the kind of improvements we want to make to the rest of the app over time. In particular, we now disable inputs if the scenario is locked, validate that the numbers entered in this page are in fact numbers, and the 'enable/disable SHW' checkbox has moved onto the page itself rather than sitting on the sidebar.

In the near future we'll be adding a feature to this page to allow users to use the options listed in SAP rather than needing the values from a test certificate, or guessing them.

Smaller changes

• We removed the 'detailed list' from the lighting, appliances and cooking page. This was unused and we didn't recommend people used it – it gave a spurious level of certainty to the calculations.
• We made the code that saves assessments to the server more resilient to errors.
• Fix report output re aesthetics booleans
• Generation now has a fuel cost (again, in new assessments only). This means that in the 'fuel costs' section the overall cost gets calculated correctly – previously generation has no way of impacting on running costs. This saving will also be shown on the new report (see below).

Reliability

We introduced a bug in early February which caused some building fabric elements to have their areas calculated wrong. We fixed this and informed everyone whose assessments it affected. Every time we find a bug like this we try to work out how we can catch it before it affects anyone through automated methods, and this case is no exception. We have since added an approach to automated testing that would help prevent this bug making it to the live service in future.

Another bug meant that briefly a user could not start a new assessment. We've fixed this one but we've not yet written the tests that would prevent it. So far with HRP, we've been focusing on testing the HRP server software and the model calculations, but it's clear we do need some automated testing for the user interface too. That's one of the top things on our list for the next month.

New report template

We've also been working hard on a new report template for our users over the last couple of months and it's almost ready to launch. We'll be in touch with tech leads at our partner organisations before this goes live to finalise the text for each organisation's report.

Future plans

Our plan with HRP in 2022 is to work on foundational improvements: improving reliability and reworking the application internally so that we can make changes faster in future. We have quite a lot of behind-the-scenes plans for Q2 2022 but in terms of user-visible stuff, we hope to bring online:

• the solar hot water estimator (mentioned above)
• a rework of the 'household questionnaire' aspect of the tool, designed to be more thorough, so we can e.g. make better recommendations about heat pumps
• a new floor U-value calculator, as we're aware this is something that users can struggle with a bit at the moment.