8. ECONOMIC CONSIDERATIONS FOR ADAPTABILITY IN BUILDINGS
8.4 Lifecycle extendibility of adaptable buildings
The application of adaptable techniques, tools and products is highly appreciated in the manufacturing, service and production industries when the products are driven from mass production to mass customisation. These innovative techniques (i.e. loose fit, plug and play) are often exploited in built environment facilities to extend their lifecycles. The ability to respond to future change is considered as innovative architecture (RIBA 2009) and adaptable buildings have high potential to respond to future changes. In this realm, design for change of use is assumed to be innovative and a good long-term investment. These issues were tested by analysing the opinions of the 32 architects and 42 quantity surveyors who responded to WBS2 and WBS3, respectively. See Figures 8-6 and 8-7 for more details.
Figure 8-6: Architects’ views on the statement “designing buildings for change of use represents innovative architecture”
Figure 8-7: Quantity surveyors' views on the statement “designing buildings for change of use represents a good long-term investment”
Only three architects and two quantity surveyors disagreed with the assertion that designing new buildings to facilitate future change of use represents innovative architecture, with the strong majority of both groups considering that the statement was either definitely or probably true. Thus, this study concludes that designing buildings to facilitate future change of use represents innovative architecture, which provides good long-term investments to its owners/developers. Moreover, the respondents were asked about their attitudes on
‘increasing the floor to ceiling height of a typical building (e.g. from typical residential to commercial heights) would be a good way of increasing its future convertibility’. Their attitudes on this issue are illustrated in Figures 8-8 and 8-9.
Figure 8-8: Architects' views on increasing floor to ceiling height increasing building convertibility
Figure 8-9: Quantity surveyors’ views on increasing floor to ceiling height increasing future convertibility
Similarly, there was support for the statement that increasing floor to ceiling height increases future convertibility. However, this support was not as strong as for the previous assertion.
Altogether, 32 (n1) architects and 42 (n2) quantity surveyors views were taken into consideration. The results explain that 10 of the 74 respondents strongly agreed, 31 agreed, 21 were neutral and 12 disagreed with the above statement. However, these views were taken from two different samples and it is necessary to analyse the variance of their ideas.
Thus, the t-test was used to compare the mean values of two samples with 72 (n1+n2-2) degrees of freedom. The null hypothesis was ‘there is no difference between the views received from architects and quantity surveyors for the above statement’. The calculated t-value was 3.65 and this exceeds the tabulated t-values (t-test table) for p = 0.05 and 0.01, as well as 0.001. Thus, the result has a 99.99% level of significance.
In short, this section concludes that practitioners’ views on increasing the future convertibility of buildings include designing higher floor to ceiling heights. The next section elaborates the practical options for increasing the floor to ceiling heights of buildings.
8.4.1 Practical options for increasing floor to ceiling height
As elucidated before, the possibility for building change of use is evaluated in terms of floor to ceiling height. The ultimate need is to make the building more adaptable for future change of use, which primarily depends upon its designed floor to ceiling height. More importantly, other design parameters (plan depth, design loads, structural span, etc.) need to be considered in a flexible manner for prospective change of use. Typical scenarios for increasing the floor to ceiling height of a multi-storey building were considered in WBS2.
First, respondents were asked about their views on the statement: ‘running building services through the structural beams in a multi-storey framed building is an effective way of maximising finished floor to ceiling height without increasing the overall height of a building’.
For the results, see Figure 8-10.
Figure 8-10: Architects’ views on increase floor to ceiling height by integrating services and structural systems
Highly positively, 5 respondents strongly agreed with the above statement and 21 of the 32 respondents agreed. However, 5 were neutral and 1 respondent was not sure about his/her answer to the statement. Second, the respondents were requested to give their views on the statement: ‘increasing the structural floor to floor height and thus the overall height of the building is the most frequent way of increasing the finished floor to ceiling height’. Two strongly agreed with this statement and 17 respondents agreed with it; 9 had a neutral attitude about this statement, 3 disagreed and again 1 was not sure (see Figure 8-11).
Figure 8-11: Architects’ views on increasing floor to ceiling height by increasing structural floor to floor height
The majority of the respondents to WBS2 believed that integrating services and structural systems is an effective way to increase the floor to ceiling height of a building. On the other hand, they stated that increasing the structural floor to floor height and thus the overall height of the building would be the most frequent way of increasing the finished floor to ceiling height. However, the most popular choice (increasing the total height of the building) would not often be appreciated in the planning and building regulations process. Thus, the respondents to WBS2 and WBS3 were questioned on their attitudes on ‘increasing the overall height of a building in a town centre is not usually an option due to planning restrictions’. Of the 32 architects, 15 agreed with the statement. However, 10 disagreed: 1 of whom strongly disagreed (see Figure 8-12).
Figure 8-12: Architects' views on planning restrictions affecting the increase of building heights in town centres
Moreover, question 6 of WBS3 (see appendix D3) was used to understand quantity surveyors’ views on how planning restrictions would affect the height increases of buildings in town centres. Of the 42 quantity surveyors, 3 strongly agreed that increasing the overall height of a building in a town centre is not usually an option due to planning restrictions. A further 20 agreed and 10 disagreed with this statement, whilst 9 responded neutrally. The results are illustrated in Figure 8-13.
Figure 8-13: Quantity surveyors' views on planning restrictions affecting the increase of building heights in town centres
Again, the t-test was used to compare the mean values of both architects’ and quantity surveyors’ attitudes on the above issue. The calculated t-value was 0.73 and this exceeds the tabulated values (t-test table) for p = 0.25. Thus, the result has a 75% level of significance.
This section explained the lifecycle extendibility (potential for change of use) of buildings with high floor to ceiling heights. The most frequent and effective ways to increase the floor to ceiling heights of new buildings were proposed through empirical evidence. The next section explains the economic considerations for adaptability in buildings.