News

Updates since January 2026:

Comparison page changes

The comparison page no longer has the extended per-scenario comparisons with their ancestor scenario, but does have new tables comparing fabric elements and radiators across all scenarios. We will look into adding the graphs from the report in here later in the year.

Completed rewrite

The part of HRP that runs in the web browser is now entirely written in a different programming language than it was five years ago! It's been a long transition but along the way we have delivered a lot of reliability and usability improvements. The last piece of this went live around late March and some of our users bumped into problems caused by this last piece of the transition, but they're all ironed out now - we appreciate your patience.

We've also continued work since then to modernise the code and the way we store data. We had to keep the new code working with the old code and this meant not improving a lot of things that would break compatibility; but now there is no old code, so we can clean up a lot of things. Again, this isn't visible to users - but it does get things to a place where we can make larger-scale changes and be sure we're not breaking anything.

Minor changes

• Added per-section heat loss totals on fabric page
• Subdivide 'subtract from' dropdown on fabric page by element type
• Make all fields readonly when scenario is locked or assessment is marked complete
• Include a notice at top of page when there is a lock in place & remove error messages when navigating around an assessment when it's marked as 'Complete'
• Improvement in page load times (there's less to load since the rewrite finished, and we've also set things up so that the 1.5MB library file is only downloaded when it's changed rather than every load)
• Updated fuel costs (apr 2026)

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app.

Updates since October 2025:

New fuels manager

The fuels manager has been rewritten as part of our (now almost complete!) rewrite of HRP over the last years. The new layout is easier to read at a glance.

There's also now a 'last updated' field. It's highlighted in red if there is newer fuel pricing information available, and you can update to the latest fuel pricing data by clicking the "update fuels" button on the top left of the page. We recommend that you do that if you are revisiting an old assessment and re-modelling the situation.

New heating system section

The heating systems section of the Heating page has been rewritten and looks a little different now. There's two major usability enhancements here. The first is that warnings will now appear when the fractions of the different systems do not add up to 1, or when the main/secondary heating system fields are set to values that don't make sense.

The second is that we've added some fields to the libraries to avoid assessors needing to enter that data every time. For example, a gas boiler will only be able to use gas as its fuel now. This removes a longstanding complaint, and all we can say is sorry it took so long to make it happen! We've also added a 'provides water/space/water+space heating' field to the libraries so that you don't have to specify it manually most of the time after adding a system to an assessment. The library updates to make use of this feature are currently being worked on, but will be finished soon.

Minor changes

For households in Scotland, flood risk input is improved and aligns with the Scottish government data.

The import/export page has also been rewritten, but there is no functionality change.

Future plans

In early 2026 we'll be working on producing Home Retrofit Plan reports (Medium Term Improvement Plans in PAS2035 terminology) and outputting more useful information for heat pump installations, both as part of our Community of Practice project.

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app.

Updates since December 2024:

• Each scenario can now have its own set of heating hours. This is most relevant where someone is currently under-heating but plans to switch to a heat pump.
• Rewritten SAP worksheet page which is more comprehensive and clearer about how HRP deviates from SAP
• 'Fuel requirements' page was rewritten and renamed to 'energy use'
• Partial rewrite of heating page (no functionality changes but it appears a little different and more consistent with other parts of the application)
• Fuel cost data update to latest Ofgem price cap + SAP 2024
• There is now always at least one fuel for fans and pumps
• floor elements can have default floor types for the calc so they don't default to a 'custom u-value' of 1 (ot yet taken advantage of in the libraries)
• implement embodied carbon graphs (not yet in report, except fig 7 which has had a change of methodology)
• Assume medium global TMP value in absence of a user decision
• Show embodied carbon data on comparison page measure summary tables
• Add reference field in report generation
• Add select all/deselect all to bulk measures on fabric page
• Various additions and minor reorganisation of the address search page
• Include party walls in 'wall' total on the house graphic
• Make sidebar text a little smaller so more can be shown at once
• Fix report generation scenario selection bug
• 'Standardised heating mode' (used in the report) now assumes a constant mean internal temperature of 20, rather than a particular heating schedule (aligning better with AECB CLR Step 1)

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app.

We have overhauled the SAP Worksheet page so that it should now be much more useful. It includes the units for all figures and a brief explanation of each section.

We will be enabling it progressively over the next few weeks in order to gather feedback, first within PPR, then for Tech Leads in partner organisations, then across the board.

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app!

It's been a little while since the last update so here's a roundup of changes since the summer:

Assessment & organisation management

We rewrote the assessments page and added a search feature to it. In future we'll add in pagination as we're aware that for some users the list of assessments is getting rather long!

We also out the organisations management aspect from the front page and added an organisation page. You can access this via the "Organisations" link on the top right of the tool. Organisation admins now have the ability to invite their own users rather than having to email us about it.

On the project page we added the ability to reassign ownership of an assessment.

Heating hours input

We've finally overhauled what was one of the most annoying parts of data entry - the heating times on the questionnaire page. It'll now let you know if you've made a mistake much much sooner. We're aware that it doens't catch all possible errors still - if you put the times not in order or you leave a row as a gap this is still a problem - but we'll add warnings about those too shortly.

Price updates

We have updated our price data to the OfGEM price gap Jan-Mar 2024.

Address search

We added a few extra fields:

• groundwater flooding status
• overheating status (England only)

And improved:

• the exposure map - now viewable as GIS data with higher reslution
• frost attack risk - now automated based on the tables in NHBC Standards 2019.

We have a larger piece of work on the address search page landing in the next few weeks.

Reports

We changed the external design temperature calculation for heat pumps so instead of assuming a constant temperature for the whole of the UK, it varies per CIBSE A. In built-up areas this will result in more reasonable external design temperatures. This will also appear on the address search page in the next few weeks.

Comparison page

It's slightly easier to use - the data for each scenario and the overall summary is hidden behind a click so that you can more easily find the thing you want without having to scroll the whole page first

House graphic & in-app reporting

And inside the tool, we improved the design of the page header: the house graphic now uses colour to help differentiate the different numbers, and the graphs to the right also use colour and are no longer pixellated. The same design is now used on the commentary page.

We also changed the numbers shown in the app to match up better with what appears in the report: so the headline numbers are now space heating (SHD), EUI and peak heat load.

SHD and EUI are both shown in their normal form plus in their standardised form (with a consistent internal heating target of 21 degrees and with 9 hours of heating on weekdays and 16 hours of heating on weekends to model comfort take-back). The two different measures aren't labelled right now - but the top one is the non-standised figure. We'll add this to the in-app display in the next weeks to make things clearer.

Thanks for reading

And of course, we continue to make improvements to our implementation of SAP and code quality behind the scenes.

We'll shortly be enabling some new sharing controls, plus some general design changes in HRP:

• The biggest design change is purely cosmetic - we're moving to a blue-and-grey pallette in the app from the red-and-beige
• The assessment title and description are now in the top left hand corner of the page, so even if you've scrolled down the sidebar you can see at a glance what assessment you're editing
• We've added a new Project page, where you can edit the name, description, and status of a project
• The Project page also contains access controls, so you can see who has access to a project and (if you're an organisation admin) share and unshare with other people in your organisation

We will be adding some more features to the new page (such as the ability to reassign ownership of a project) in the near future. More announcements about that to come.

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app.

We've made some updates to the standard report format that is used by several organisations. These updates were mainly focused on the text in the report and we felt they were needed to better explaining some of our approach and a couple of key issues in retrofit, in response to client queries and an emerging consensus on best practice in the industry:

• Balancing decarbonising heat and ‘fabric first’ approaches: We now better explain what we mean by ‘fabric first’ and how this relates to ensuring homes are ‘retrofit ready’ through repairs and maintenance, and how recommended retrofit strategies respond to client aims.We encourage the decarbonisation of heat while paying attention to client priorities, budgets, building condition, and comfort and health needs. We’ve also better explained changing heating patterns and radiator sizing practices to support efficiency of both condensing boilers and heat pumps. (Text has been updated in ‘Our Approach’ and section 2.21 to support this).
• The importance of well-performing ventilation systems: We are keen to support good indoor air quality in homes, so we have also updated the text on ventilation within the standard report to support this. We’ve explained our preference for continuously running mechanical ventilation systems (section 4.5). We’ve also added some further explanatory text on woodburners, highlighting their negative pollution and carbon impacts (section 4.5.2).

Alongside these bigger thematic updates, we’ve taken the opportunity to improve and tweak other aspects of the standard text and labelling of graphics, clarifying in response to feedback. In doing this we’ve also taken the opportunity to pick up on typos. We’ve also added the following:

• A note on the second page about the provenance and development of the Home Retrofit Planner software.
• Section 3.3, ‘Quick Wins’: added information on lighting and laundry, updated text on renewable energy use and monitoring.
• Section 5.2, ‘Next Steps’: Updated text on help available from People Powered Retrofit. (There is an opportunity for other organisations to do the same).
• Glossary: Added text on air to air heat pumps, boiler upgrade scheme (BUS), MEV, dMEV, MVHR, VAT. Updated text on ASHP, GSHP, LETI, RHI.

We hope that all of this makes the report a more useful document to both clients and the householders supporting them. As ever, feedback is always welcome - and if you spot any typos, let us know!

Further updates will be coming soon - especially in Section 4 on context and in measures libraries. We’ll share with partner organisations for comment before these are implemented.

We will shortly be rolling out some changes to HRP's navigation sidebar. You can see the old version on the left and the new version on the right of this image:

The changes we've made are as follows:

• The current page and scenario are highlighted clearly on the sidebar.
• The buttons to copy/delete/lock a scenario are just below the scenario name.
• When making a new scenario, you're prompted for its name straight away rather than having to go into the 'dwelling data' page to alter it. New scenarios are now created by clicking the 'new' button under the scenario that you want to base the new scenario off.
• You can have multiple scenario sections open in the sidebar at once.
• Opening or closing a scenario section on the sidebar doesn't automatically navigae to that scenario - now you have to click on the page you want to navigate to in order to go there.

As usual, if you have any queries, questions or complaints, please reach out to us on support@retrofitplanner.app!

A smaller batch of bugfixes and smaller improvements this month, since the last update was in March. We'll be posting these quarterly from now on, to sync up with our technical leads meetings.

• Use latest SAP fuel figures (Feb 2023)
• Wall elements that have zero for area are marked as 'deleted' for clarity.
• Clarified text on heating page about instantaneous water heating - this toggle is for heating at the point of use, e.g. for electric showers, but users were previously using it for boilers. Hopefully the new text is clearer.
• Solar hot water page cleaned up -most of the time the calculations on the SHW page are excessive, and users often miss filling out the inputs which were lower down the page. We've switch to a layout where only inputs are presented, but you can toggle the display of the full SAP worksheet-like calculations too if that's useful.
• Show more info in the title bar of the browser - previously just said "Home Retrofit Planner", now will include the scenario, project title, etc.
• The commentary page has changed behind-the-scenes in a way we hope will make data loss issues related to this page a thing of the past. Please tell us if you encounter issues with it!

Also, please don't navigate away from the image gallery while uploads are in progress; the uploads might not complete.

Our induction process for new retrofit surveyors up until now has been to add them to a 'training' group on the app. Then after the training phase is complete, we remove them from that group and add them to their organisation's group. As we've grown in size, this training group has become a bit unmanageable for us. We haven't had a good system for tracking who should and shouldn't be in it, and people have ended up in more than one group. Some users have found this confusing.

So, we've decided to remove the training group. This won't make any difference to most of our active users because most of them aren't in it. However you might have had a test or experimental assessment in this group. If so, it's not lost! You still have access to it, it's just a private assessment now.

As usual, if you have any queries or questions, please reach out us on support@retrofitplanner.app!