Table 1
Backgrounds of the research participants.
| ID | AGE (YEARS) | GENDER | HEATING SYSTEMSa | YEAR MOVED | BUILDING TYPE: PREVIOUS; CURRENT | INCOME LEVELb |
|---|---|---|---|---|---|---|
| r01 | 55–64 | Female | Electricity, wood stove, ASHP | 2021 | Detached; detached | Middle income |
| r02 | 65–74 | Male | District heat | 2022 | Detached; apartment block | Low income |
| r03 | 55–64 | Male | District heat, ASHP | 2024 | Detached; terraced | Middle income |
| r04 | 45–54 | Female | Electricity, ASHP, two wood stoves | 2023 | Detached; detached | Middle income |
| r05 | 35–44 | Male | Electricity, wood stove, ASHP, solar panel | 2020 | Terraced; detached | Middle income |
| r06 | 35–44 | Female and male | Electricity, ASHP, solar panels, wood stove | 2021 | Semi-detached; detached | Sufficient |
| r07 | 75–84 | Female | GSHP, ASHP, fireplace | 2020 | Apartment flat; detached | Constrained |
| r08 | 35–44 | Male | Electricity, two ASHPs, wood stove | 2021 | Semi-detached; detached | Middle income |
| r09 | 65–74 | Female | WAHP, solar panels, ASHP, wood stove | 2021 | Detached; detached | Middle income |
| r10 | 45–54 | Male | Electricity, wood stove, ASHPs | 2021 | Terraced; detached | High income |
| r11 | 65–74 | Male | District heat | 2022 | Detached; low-rise apartment block | Sufficient |
| r12 | 55–64 | Male | EAHP, floor heating, ASHP, solar PV | 2021 | Apartment flat; semi-detached | Middle income |
| r13 | n.a. | Female | Electricity, wood stove, ASHP | 2020 | Apartment flat; detached | Middle income |
| r14 | 35–44 | Male | Electricity, two ASHPs | 2021 | Terraced; detached | Below middle income |
| r15 | 25–34 | Female | Electricity, ASHP, wood stove | 2022 | Terraced; detached | Middle income |
| r16 | 55–64 | Female | District heat, ASHP | 2021 | Apartment flat; semi-detached | Sufficient |
| r17 | 35–44 | Male | Electricity, ASHP, two wood stoves | 2021 | Terraced; detached | Sufficient |
| r18 | 55–64 | Female | Electricity, ASHP, solar panels | 2011 | Detached; detached | Sufficient |
| r19 | 55–64 | Female | Electricity, solar, wood stove, two ASHPs | – | n.a.; detached | Sufficient |
| r20 | 65–74 | Male | ASHP, wood stove, electricity | 1989 | n.a.; detached | Constrained |
| r21 | 65–74 | Female | Electricity, two ASHPs, two wood stoves, sauna | 1985 | n.a.; detached | Sufficient |
| r22 | 65–74 | Female | WAHP, wood stove | 2023 | Apartment flat; detached | Sufficient |
| r23 | 55–64 | Male | Electricity, two wood stoves, ASHP | 1998 | Semi-detached; detached | Middle income |
| r24 | 55–64 | Male | WAHP, wood stove, electricity | 2011 | Detached; detached | High income |
| r25 | 75–84 | Male | GSHP, ASHP | 2001 | Detached; detached | High income |
| r26 | n.a. | Female | GSHP, wood stove | 2014 | Detached; detached | Middle income |
| r27 | 65–74 | Male | Electricity, wood, EAHP | 1994 | Detached; detached | Low income |
| r28 | 45–54 | Female | ASHP, electricity, wood stove | 2013 | Apartment flat; detached | Middle income |
| r29 | 55–64 | Female | Electricity, ASHP | 2023 | Detached; semi-detached | Middle income |
[i] Note: aASHP = air-source heat pump; EAHP = exhaust-air heat pump; GSHP = ground-source heat pump; WAHP = water-to-air heat pump; PV = photovoltaic.
b‘Sufficient’ income level refers to a situation where a respondent’s income level is not exactly known, but the interview situation did not reveal the existence of significant economic constraints. ‘Constrained’ refers to an income level that is not exactly known, but the respondent is a pensioner, in debt or without a financial buffer.
