The value of the HQM ONE indicators
HQM’s indicator scores can be used to draw out performance in particular areas including: running costs, health and wellbeing and environmental impact. Each of these indicators has backstops for scores of 3 or higher. These backstops give confidence that a home with a high indicator score is meeting key requirements relating to that rating. For example, to achieve a My Wellbeing of 3, a home needs to meet good standards for ventilation, thermal comfort, indoor air quality, daylight levels, sound insulation and indoor and outdoor space.
There are three sub-scenarios within this scenario, which are all based on the same 2-bedroom house, located on the same site within a medium-sized development. Each house has the same basic design and construction and some shared features that are outlined in the assumptions section. To show how HQM’s indicators work, each of these houses has also focussed on different features that particularly support one of HQM’s indicator scores:
- Scenario 1a focuses on low running costs
- Scenario 1b focuses on health and wellbeing
- Scenario 1c focuses on a reduced environmental impact
Shared Features of Each Sub-Scenario
Location and Space
- Semi-urban location with reasonable transport links typical of a more urban setting
- Local amenities include one supermarket within walking distance
- Low flood risk as a result of location or control/resilience measures undertaken
- Large communal garden space is accessible to occupants of the development
- 1 cycle storage space per home
- Airtightness testing has been carried out at post-construction stage
- Feedback and lessons learnt from construction process are communicated with parties involved with the project team to improve quality for future projects
Building on the shared features, each home’s differing features are outlined below (for details of what each statement requires, please see HQM ONE manual).
The key shows the proportion of credits that have been scored for each issue. Each issue contributes a different amount of credits to reflect how much value they are adding to the home’s overall levels of quality and sustainability. To help give some context to what each issue is worth, the ‘credits %’ column shows how much the credits contribute to scoring a 5-star Outstanding rating (i.e. at least 400 out of 500 credits). To take the first entry in this scenario’s table as an example, scenario 1b is receiving a low amount of credits for HQM’s ecology issues, which contain 9% of the total credits available in HQM that are required to achieve a 5-star home. In contrast, scenario 1c is achieving a high number of credits for this issue.
The star ratings achieved for each scenario are similar or the same and HQM has been designed for this to happen. Projects can focus on different areas to draw out specific value, while still being recognised for their overall quality. The minimum requirements provide the quality baseline for every home with an HQM certificate and the different indicator scores and optional credits provide flexibility.
A higher star rating was achieved for the ‘Reduced environmental impact’ scenario. This is because there are more points available that contribute to the ‘My footprint’ score, which means a higher number of credits are needed to achieve the same percentage score boundary for the indicators.
- For example, the score boundary for a 4 in all indicators is 48%. This percentage represents a higher number of credits for the My footprint score because there are more points that make up that 48% and more credits that need to be achieved as a result. This means that a project scoring 48% of the ‘My footprint’ points may achieve a higher star rating than a project scoring 48% of the ‘My cost’ points
Many credits contribute to more than one indicator but to different extents. This is to recognise the different benefits that features can have.
- For example, energy efficiency has a very high impact on My footprint and My cost indicator scores because it can significantly reduce Carbon emitted for the home’s energy needs as well as energy bills.
Some of these scenarios scored enough points to achieve a level 3 for indicator scores but were capped at a level 2 because they did not meet the relevant backstops required for the higher level. For instance, the Health and Wellbeing scenario (1b) could have achieved a My Cost score of 3 if it met the backstop for good standards of water efficiency.
Some backstops and indicator points overlap. For example, the level 3 backstops for My Cost are water efficiency and flood risk (low risk location or prevention and resilience measures are in place). Water efficiency is required by My footprint 3 and flood risk was a general assumption that applies to the location for all scenarios described above.
Some credits chosen in the sub-scenarios contribute to meeting more than one indicator score but for the purposes of these scenarios, we have focussed on credits that have more significant impact on each indicator. For example, good daylight levels can contribute to reduced running costs through reduced energy usage for lighting but have not been met for the ‘running cost’ scenario. These are illustrative examples to show that there are different credits that can be focussed on to achieve a variety of benefits.