We provide the AECB REALcosting software as described on their page (link opens in another tab) www.aecb.net/carbonlite/phpp-software/realcosting-phpp-v9-6/

REALcosting is now merged into PHPPtools and can do almost everything REALcosting does. REALcosting can add co-benefits and calculate changes in house dimensions from external insulation, which makes more accurate thermal bridge calculations. Features of REALcosting include
• quick and simple to use, writes PHPPs for you
• has 11 standard construction build-ups you can edit
• built in Thermal Bridge Library
window tool for entering complex windows quickly and simply
• simple reporting with extra detail if needed
• breakdown of energy use and costs by building element
• includes fully working example of a semi-detached house

Watch our 5 min tour of REALcosting features:

All Climate data is brought together in one convenient place:


Standard constructions mean you don’t start from scratch:


A window tool makes it easy to enter multiple windows, which can save hours, it enters the dimensions of each pane, ‘1’s and ‘0’s and the average d reveal: (Now also available as a separate addin for PHPP! Please ask us for this if interested.)


A thermal bridge library helps you enter typical thermal bridges easily:


Costs are easily summarised in a table for your reports (below). With the dialog you can show quantities, rates used and a library of costs so you can edit them. Space is given for you to add add extra items and you can remove any not relevant.


Results are divided into Energy and Cost. The energy for heating, Space Heat Demand, is given here as a yearly total on the Results tab and is also broken down by building element. Costs are given in todays money, Net Present Value, including the cost of the build, heating, maintenance and the cost of running the MVHR or MEV. A breakdown of costs by time and building element is given on the ‘Time’ tab.


3 Purchase Options

1) Buy the software, do the training, and use it yourself with your own PHPPs
Recommended for those who may be involved in regular retrofits and have the PHPP software. We’re offering a 20% discount, the software is now £128, either the standard or incremental version, (down from £160) and £160 for both. If you’d like to use it on more than one computer, additional computers can be used for £40 each and will be for the same choice of version(s) as the first. REALcosting creates completely normal PHPPs, these can be checked as you normally would.

2) Consultancy – we do the work for you
You can take advantage of this software without buying it. This is a good option for those with limited time, perhaps those without PHPP, or where projects are complex or where results are needed for just one project. You also get the benefit of our expertise. Please contact us for details.

3) Budget hybrid option for those without PHPP
With this option you buy the software slightly cheaper at £80, do the training, fill out REALcosting spreadsheets and send them to us to produce the PHPP’s. Details of the software are as for option 1.
This is a good option for those that might be doing occasional work with REALcosting and do not want to buy PHPP. Or perhaps you have PHPP but are fairly new to it and would like us to check over it. It does involve a little consultancy time in checking the input information is sensible and the PHPP. The advantage of this is that you don’t need to buy PHPP and the consultancy hours are much less because you are doing most of that data entry yourself.


REALcosting Software contents and Minimum Requirements

The licence is non-expiring and it includes

  • the software including the Thermal Bridge library
  • credit for a half day of training. This is partly by videos, partly by online seminar. Videos give you flexibility of timing and the ability to repeat parts.
  • updates if any corrections to the present version are needed
  • manual and a support package

REALcosting software requirements are:

  • PC computer (because of the programming language used)
  • The software is tested with PHPP v9.6a, currently the latest version, if you have an earlier version of 9 I would be happy to check compatibility for you, please ask. Or you can upgrade to 9.6a for free via the Passivhaus Institute.
  • You should have some training in PHPP, this is available separately via the AECB. This is needed because REALcosting writes PHPPs which you should know how to check and modify.
  • You will also need access to drawings for the building in order to be able to read areas off. If you don’t have access to those you can use your own measurements, however we recommend you still sketch it out.


Frequently Asked Questions, FAQs

Do I get any technical support?

We now include technical support free of charge, you can also ask as many questions as you like during the training.

Do you offer consultancy if I need it?

Yes, some buildings are more complex than in the training, Tim Martel provides extra consultancy, please contact tim@aecb.net for further information.

How do I change the costing information?

This is very straightforward, you can just change the values in the yellow cells of the costing table, they are meant to be updated from time to time.

How accurate is it?

REALcosting has been thoroughly checked and tested over the 3 years used for the AECB and during further extensions of the software, and it continues to be used on live projects. We recommend that you attend the training and check the PHPPs created. Programming errors are unlikely and as we say it has been tested to prove it gives the results we expect, but if you find anything astray we will correct it free of charge. REALcosting energy calculations have a sound basis in using PHPP, cost calculations are indicative, however you can refine them through discussions with your builder.

Can I have more than 6 scenarios?

At the moment, not yet within the same REALcosting file. You can of course duplicate the file and, using the same base case, enter 5 new scenarios.

Could it be available for Mac in the future?

This is very unlikely, the software relies on Visual Basic which is built into Excel on PCs, Apple Macs do not have this feature.

Why does the semi-detached house give different a result to the CLR course figure?

CLR course figures were calculated in an earlier version of the software which used PHPP 2007 which was current at the time when the software started development. We have gone through several major revisions of PHPP since then, 8.5, 9.0 and 9.6a which modify PHPP results.

Can we add more co-benefits?

So far we have included two, both optional, how much the extra comfort is worth to the occupier per year and the increase in house value. The government suggest the increase in house would typically increase in value by 14% here for example https://www.gov.uk/government/news/energy-saving-measures-boost-house-prices. The increase in house value may be recognised more over time and as a conservative estimate you may choose not to include it. Part of the difficulty for many co-benefits is that it is difficult to put a price on them. If you come up with another co-benefit and a justifiable way of calculating it we will add it in to the next version.