Passivhaus social housing: Cost research
The Trust and its partners have previously developed information about the costs of Passivhaus social housing units, both in terms of capital costs and in terms of running costs. However, the capital cost figures are now out of date, as they represent the first few schemes undertaken by their respective clients, and as such include an additional cost for innovation, which should come down over time. The Trust are currently updating this research, and have summarized below our interim findings. We anticipate a report of the research to be published later in 2017.
Capital Costs
There can be an additional capital cost for Passivhaus homes, if you keep everything else (design standards) the same. If, however, you are willing to adjust the design to be more efficient for Passivhaus (form, orientation, windows etc.) then it can be possible to achieve the Passivhaus standard at no extra cost. This has been achieved by Exeter City Council on their latest two schemes, because they set their brief to achieve this, and adjusted the designs accordingly.
Silverberry Close, Exeter. Gale and Snowden
Operational costs
There will be a significant saving in energy costs for occupants of a Passivhaus home. Some residents quote about average annual heating bills of approximately £150 for a typical 2 bed terrace, although this obviously depends on the lifestyle and behavior of the occupants. In Exeter, they have found that some tenants have not needed to use their heating at all for several years. All that money remains in the pockets of the tenants, and can be spent locally! Obviously, this does not benefit the Council directly, but the experience of Hastoe Group is that they achieve lower voids and lower rent arrears (almost zero in both cases) for Passivhaus homes because the comfort and cost benefits are so great that tenants don’t want to risk losing their property.
 document.jpg "Wimbish Passivhaus, Parsons + Whittley for Hastoe HA")
Wimbish Passivhaus & Bunrham Overy Staithe, Hastoe Housing Schemes
Whole Life Costs
Whole-life costing analysis accounts not only for capital costs, but also for the total operational (fuel bill) and maintenance costs, which are summed over the lifetime of the building. Fuel price rises, tax and inflation can also be incorporated into the analysis when appropriate. In 2014 a paper published by Encraft demonstrates that in most scenarios (and even if it costs 10% more to build), a Passivhaus will have lower whole-life costs than a traditional new build. Choice of building services is critical, however, and selecting those with lower maintenance and replacement costs is highly recommended.
We are currently working to update information on capital costs for social housing and will then move on to capital cost information for single dwelling homes. If you have cost information that you would be willing to share, then please email kym@passivhaustrust.org.uk. Ideally we are looking for projects that are certified, but would be willing to include non-certified schemes that are complete and meet the standard
Once the report is complete, the Trust plans to begin capital cost research of other building types such as educational buildings and non-domestic schemes, and to develop further the research into whole life costings, and sales values.
Further Information
Passivhaus Knowledge Base - Featured Guidance: Costs
Why more housing providers should be building to Passivhaus
