Scottish house condition survey: 2018 key findings

2 Key Attributes of the Scottish Housing Stock

14. The Scottish House Condition Survey provides a snapshot of the Scottish housing stock in each survey year. This chapter sets out information on the basic attributes of occupied Scottish dwellings as captured in 2018. Subsequent chapters build on this and provide more details on energy efficiency, fuel poverty, housing quality and disrepair.

15. The following topics are included:

• the construction age and built form of Scottish domestic buildings;
• the dwellings’ location in relation to the gas network and the type of fuel used to heat them;
• the relationship between the dwellings’ attributes and household tenure; and
• the composition of the households who occupy them.

2.1 Dwelling Age and Type

16. The age of construction and the built form of a dwelling has consequences for energy performance, running costs and living conditions. For example, older dwellings built with solid stone walls are typically less effective at preventing heat transmittance between the inside and the outside of a building than properties that have been built using modern construction materials and that, since 1982, have been subject to increasingly rigorous minimum standards of energy efficiency and airtightness.

17. More information on the main dwelling types used in the SHCS is provided in section 7.11.1.

18. At the same time, types of dwellings can differ in terms of the size of the external surface area; dwellings with a smaller area of exposed wall, for example amongst those that are shielded by adjacent properties, typically have lower levels of heat loss than in buildings with fewer sheltered sides.

19. The Scottish housing stock is diverse and varies across the country and between rural and urban areas. However, some common types can be recognised in Figure 1:

• Old (pre-1919) detached houses (4%; around 102,000) and tenement flats (7%; 181,000)
• More modern post-1982 detached houses (11%; 261,000) and tenements (7%; 165,000)
• Post-war terraced houses (14%; 343,000 built between 1945 and 1982)
• Semi-detached houses, common across all age bands and accounting for around 20% of the stock alone.

20. These six broad categories account for 63% of the overall housing stock. However, there is also a good deal of variability within these groups; even among pre-1919 tenement flats of the type common in Edinburgh and Glasgow, there is a wide range of sizes, shapes and areas of exposure (for example in top floor flats the roof is exposed) which affects their energy efficiency and the living conditions experienced by the household.

Figure 1: Number of Occupied Scottish Dwellings by Age Band and Type, 2018

21. The proportion of the stock in each dwelling age band and type is provided in Table 1. Numbers of dwellings of each age group and type are shown in Table 2.

Table 1: Proportion of Occupied Dwellings by Age Band and Type, 2018 (Percentage of Whole Stock)

Age of dwelling	Type of Dwelling
	Detached		Semi-detached		Terraced		Tenement		Other flats		Total
pre-1919	4%		2%		3%		7%		2%		19%
1919-1944	1%		3%		1%		2%		4%		11%
1945-1964	2%		6%		7%		4%		3%		21%
1965-1982	4%		5%		7%		3%		2%		21%
post-1982	11%		5%		3%		7%		2%		27%
Total	22%		20%		21%		23%		13%		100%
Sample size											2,964

Table 2: Number of Occupied Dwellings by Age Band and Type, 2018 (Thousands)

Age of dwelling	Type of Dwelling
	Detached		Semi-detached		Terraced		Tenement		Other flats		Total
pre-1919	102		53		76		181		58		469
1919-1944	36		70		30		39		106		281
1945-1964	43		142		167		107		71		530
1965-1982	110		121		176		84		38		529
post-1982	261		118		82		165		40		667
Total	552		505		532		576		313		2,477
Sample size											2,964

22. The category ‘other flats’ includes houses that have been converted to flats (36,000), towers / slabs (66,000) and so-called “4-in-a-block” flats (211,000).

• “4-in-a-block” flats were commonly built as social housing between 1919 and 1965 (70% of all flats of this type fall in that age category).
• 85% of towers / slabs were built in the 1945 to 1982 period, again often as social housing.
• Converted flats are almost exclusively pre-1919 structures (92%), where a house has been divided into multiple residences.

2.1.1 Dwelling Size (Floor Area)

23. The size of the internal floor area has implications for the heating requirements of a dwelling. Larger dwellings require greater heat inputs and therefore cost more to heat. This has a direct impact on fuel poverty (see Chapter 4).

Figure 2: Mean Floor Area (m2) by Dwelling Type and Age, 2018

24. Pre-1919 dwellings tend to be larger than the other two age categories across dwelling types with the exception of pre-1919 detached properties which on average are comparable in size to more recently built ones (Figure 2). Semi-detached houses built after 1919 are on average around three-quarters of the size of those built pre-1919. Terraced houses built after 1919 are around seven-tenths the size those built pre-1919.

25. The overall average for post-1982 dwellings is somewhat higher compared to those built between 1919 and 1982. This is largely driven by differences in detached houses, which are both larger in size and more common in the post-1982 stock (see Table 2).

26. Rural dwellings are, on average, 33% larger than urban dwellings based on internal floor area, as shown in Table 3. The difference is smallest for dwellings built between 1919 and 1982 at 13%. Among older dwellings, rural properties are around 31% larger, while among the post-1982 stock the difference is 49%.

Table 3: Average Internal Floor Area (m2) by Urban/Rural Location, 2018

Dwelling Age	Location			Rural % larger
	Urban	Rural	All
Pre-1919	99	129	107	31%
Sample size	338	183	521
1919-1982	86	98	88	13%
Sample size	1,358	277	1,635
Post-1982	93	139	102	49%
Sample size	596	212	808
All Age Bands	90	120	95	33%
Sample size	2,292	672	2,964

2.2 Gas Grid Coverage and Rural/Urban Location

27. Approximately 18% of dwellings in Scotland are estimated to be outside the coverage of the gas grid^[10]. As shown in Table 4, the majority (91%) of urban dwellings are within the coverage of the gas grid, whereas almost two-thirds (64%) of those in rural areas are not.

Table 4: Gas Grid Coverage Overall and by Urban/Rural Location, 2018

Gas Grid Coverage			Location
			Urban		Rural
	000s	%	000s	%	000s	%
On Gas Grid	2,032	82%	1,883	91%	149	36%
Off Gas Grid	445	18%	180	9%	265	64%
Total	2,477	100%	2,063	100%	414	100%
Sample size		2,964		2,292		672

28. Connection to the gas grid allows households to use gas for heating and hot water. As gas is currently the cheapest of the major commercial fuels, gas grid access can be a significant determinant in the required cost of heating a home to a satisfactory temperature.

29. Figure 3 shows the number of dwellings in rural and urban areas by property type.

Figure 3: Dwelling Types in Rural and Urban Areas (000s), 2018

30. Just over half (52%; 217,000 households) of all rural dwellings are detached, and 22% (90,000) are semi-detached. Only 8% of rural dwellings are flats; 33,000 in total.

31. The most common dwelling type in urban areas is the tenement flat (563,000), accounting for around 27% of urban housing. Around 59% of urban stock is detached, semi-detached and terraced houses, in total accounting for almost 1.2 million of the 2 million urban dwellings.

2.3 Heating Fuel

32. This section examines the distribution of dwellings in terms of the primary heating fuel used and a range of other characteristics, such as age and type of dwelling. The relationship between the type of fuel used, the energy efficiency rating and fuel poverty will be explored further in later chapters.

33. Overwhelmingly the most common heating fuel is mains gas: 81% of Scottish households (around 2.0 million) use mains gas for heating, 10% use electricity and 6% use oil (Table 5), these are similar to 2017.

Table 5: Primary Heating Fuel, Households (000s) and %, for All Stock and by Sector, 2018

	All Stock		Private		Social
Primary Heating Fuel	000s	%	000s	%	000s	%
Mains gas	2,002	81%	1,471	81%	530	81%
Electricity	247	10%	152	8%	95	14%
Oil	145	6%	145	8%	-	-
Communal Heating	32	1%	5	0%	27	4%
LPG bulk or bottled	27	1%	*	*	*	*
Solid mineral fuel	8	0%	*	*	*	*
Biomass	16	1%	16	1%	-	-
Sample size	2,964		2,231		733

“*” denotes cases where attributes appear too rarely to provide an adequate basis for reporting. “–“ denotes no sampled cases. See section 7.1.6 for table conventions.

34. Gas and electricity are the main fuel types present in 95% of social housing. A further 4% (27,000 households) use some form of communal heating which is very uncommon in the private sector. Conversely, oil is rarely used to heat social housing, with no sampled cases in 2018, but was the primary fuel of 8% of private dwellings.

35. 85% of dwellings built between 1919 and 1982 use gas as their primary heating fuel (Table 6).In comparison, 78% of dwellings built after 1982 and 72% of dwellings built pre-1919 use gas. Older dwellings more commonly (18%) use other fuel types (than gas or electricity).

36. Primary heating fuel also varies by type of dwelling. As shown in Table 6 households living in detached houses are least likely to use mains gas for heating: 68% of them do, compared to 81% of households for Scotland as a whole and 89% of those households living in terraced houses. This is due to the greater prevalence of alternative heating fuels amongst pre-1919 detached houses. Less than a third (30%) of pre-1919 detached houses use gas as their primary heating fuel; 8% use electricity and 62% use some other fuel source. As shown in Figure 3 this is largely due to the higher proportion of detached dwellings in rural areas and Table 4 demonstrates that dwellings in rural areas are less likely to be within the coverage of the gas grid.

37. “Other” fuels (than gas or electricity) are most commonly used in detached houses. Flats have the highest levels of electricity as primary heating fuel (15%).

Figure 4: Primary Heating Fuel by Age and Type of Dwelling, 2018 (per cent of dwellings in age/type category using fuel type)

Table 6: Primary Heating Fuel by Age and Type of Dwelling, 2018

Dwelling Type	Dwelling Age	Primary Heating Fuel			Sample size
		Gas	Electric	Other
All Dwelling types	All age bands	81%	10%	9%	2,963
	pre-1919	72%	10%	18%	520
	1919-1982	85%	8%	6%	1635
	post-1982	78%	13%	9%	808
Detached	All age bands	68%	6%	26%	807
	pre-1919	30%	8%	62%	149
	1919-1982	77%	4%	19%	298
	post-1982	77%	6%	17%	360
Semi	All age bands	86%	9%	5%	659
	pre-1919	68%	9%	23%	64
	1919-1982	89%	7%	4%	439
	post-1982	86%	12%	2%	156
Terraced	All age bands	89%	7%	4%	633
	pre-1919	77%	*	*	89
	1919-1982	91%	7%	3%	451
	post-1982	92%	*	*	93
Flat	All age bands	81%	15%	4%	864
	pre-1919	88%	*	*	218
	1919-1982	82%	13%	5%	447
	post-1982	69%	*	*	199

Note: There was one N/A response for Primary Heating Fuel which has been excluded from the table.

2.4 Household Type

38. In this report we describe households in terms of three main types which are derived from the more detailed classification used in the Scottish Household Survey^[11]:

• Families. These are households which contain at least one child aged under 16. The resident adults may be of any age.
• Older households. One- or two-member households which include at least one resident aged 65 or older.
• Other households. These are all other household types which are made up of adults only and have no resident children.

39. More details about the definitions are provided in section 7.11.2. This grouping was introduced in the 2015 Key Findings report and is different from the one used in previous reports, where the pensionable age for women was 60 and 65 for men. From 2015 onwards, 65 is adopted as the common age threshold for both men and women for older households reflecting the gradual increase in the state pension age for women.

40. There is a broad association between household types and the type of dwellings they occupy, as shown in Figure 5 and Table 7. While families and older households are more likely to live in houses (74% and 67% respectively), other households are more evenly split between houses and flats (57% and 43% respectively).

41. Families have the highest proportional occupancy of post-1982 houses: 26% of households with children live in post-1982 houses, compared with 13% of older households and 19% of other types of households. The highest occupancy of pre-1919 flats is observed among other types of households, 14%, compared to 6% for families and 6% for older households.

Figure 5: Proportion of Households in Each Dwelling Type and Age Band, 2018

Table 7: Proportion of Households in Each Dwelling Type and Age Band, 2018

Dwelling Type and Age Band		Older Households	Families	Other Households	All Household Types
Houses	Pre-1919	10%	10%	8%	9%
	1919-1982	44%	38%	30%	36%
	Post-1982	13%	26%	19%	19%
	Subtotal	67%	74%	57%	64%
Flats	Pre-1919	6%	6%	14%	10%
	1919-1982	18%	17%	19%	18%
	Post-1982	9%	3%	10%	8%
	Subtotal	33%	26%	43%	36%
Total		100%	100%	100%	100%
Sample size		974	667	1,323	2,964

2.5 Tenure

42. Statistics on tenure in the SHCS are based on the achieved sample of dwellings in the physical survey and are not calibrated against figures produced as part of the Scottish Government Housing Statistics for Scotland^[12] publication or the Scottish Household Survey^[13] publication (which is based on a larger sample and different weighting methodology). For estimates of the total number of dwellings by tenure, readers are referred to the Housing Statistics for Scotland publication which uses information from social landlords’ returns which comprehensively cover the social housing sector and therefore provides more accurate estimates of the total stock.

43. In this section we explore data from the SHCS sample which provides more detailed information on the composition of each tenure type.

2.5.1 Household Type and Tenure

44. There are some clear differences in household type across tenure, as shown in Figure 6.

Figure 6: Proportion of Households in Each Tenure Group by Household Type, 2018

Note: Dashed lines represent the proportion of household type in Scotland as a whole.

45. Owner occupiers with mortgages are predominantly families (43%) and other households (52%), while those who own their properties outright are dominated by older households (62%) and other types of households (34%).

46. The majority of those who live in the private rented sector (PRS) belong to other households (64%) and only 11% are older households. A quarter of renters in both the private (25%) and the social sector (24%) are households with children, which reflects their share in the national population.

2.5.2 Dwelling Type and Tenure

47. Figure 7 shows that rented properties in the Housing Association (HA) and the private rented sector are more likely to be flats. Flats account for 65% of Housing Association (HA) stock and 64% of dwellings rented from private sector landlords.

48. Owner-occupied dwellings are more likely to be houses: 78% of dwellings owned outright and 77% of those with a mortgage, compared to 49% of dwellings owned by Local Authorities, 35% of Housing Association stock and 36% of private rented properties.

Figure 7: Proportion of Dwellings in Each Tenure Group by Age Band and Type of Dwelling, 2018

49. Almost all properties (89%) owned by Local Authorities were built between 1919 and 1982, while less than half (42%) of the Housing Associations stock was built in this period. Private rented sector dwellings are older, with 42% built before 1919, compared with a third built between 1919 and 1982 (Table 8).

Table 8: Proportion of Dwellings in Each Tenure Group, by Age Band and Type of Dwelling, 2018

Dwelling Age and Type		Owned	Mort- gaged	LA	HA	Private rented
Houses	Pre-1919	13%	12%	*	*	12%
	1919-1982	45%	36%	44%	15%	17%
	Post-1982	20%	29%	*	*	7%
	Subtotal	78%	77%	49%	35%	36%
Flats	Pre-1919	8%	9%	3%	8%	30%
	1919-1982	10%	9%	45%	28%	16%
	Post-1982	4%	5%	3%	29%	18%
	Subtotal	22%	23%	51%	65%	64%
Total		100%	100%	100%	100%	100%
Sample size		1,091	846	459	274	294

2.6 Household Income Band

50. As we might expect, income and tenure are closely correlated. For social sector residents the distribution is skewed towards lower income groups, as shown in Figure 8, while households with mortgages have the largest share of higher income groups.

51. The distribution of households by income in the PRS is broadly similar to that for outright owner occupiers. It is generally wider than the social housing sector, including significant shares of both higher and lower income band households.

Figure 8: Proportion of Households in Each Tenure Group by Weekly Household Income Band, 2018