Investing in possibilities The feasibility of adaptable office buildings

1. Investing in possibilitiesThe feasibility of adaptable office buildings Peter de Jong Hilde Remøy Wiechert Schenk Real Estate & Housing – Faculty of Architecture – Delft University of Technology

2. Index • Introduction • Adaptable office buildings • The market • Recommendations

3. 14% vacancy • Sustainability

4. Objective The feasibility of anticipating future programmatic change of commercial office buildings: Legal feasibility Technical feasibility Financial feasibility Commercial feasibility

5. The adaptable office building

6. Legal feasibility • Spatial planning act • Building decree

7. Technical feasibility Structure Measurement Floor layout Horizontal and vertical extendibility (Emergency) Exits Structure flexibility

8. Technical feasibility Skin Different requirements of building physics Windows and balconies Visual design Not load bearing, easily demountable, replace or adapt to be decided if transformed

9. Technical feasibility Services Installations differ in type Installations positioned vertically versus horizontally The installations as well as the shafts are not reusable: no integration with the construction!

10. How to Design measures: measurement, layout, positioning of exits have no influence on construction costs Technical measures: construction typology influences the building costs

11. Two building types Single corridor Central core

12. Single corridor Construction: load bearing outer walls and hollow core beams Measurement: depth 14.4m, structural grid 1.8m

13. Single corridor Design measures: Structure Housing units: gallery entrance • Technical measures: • Horizontal extendibility: Columns in the facade • Vertical extendibility: Up to two floors can be added

14. Single corridor Technical measures • Structure 120 minutes structural strength in case of fire Construction type: Columns and monolithic post-stressed floors Standard construction type Preferable construction type

15. Central core Structure sturdy core and a structural grid of columns Measurement 9m. from facade to core Facade Not load bearing

16. Central core Design steps Housing units: entrances around the core Construction: Columns in the facade Measurements: Depth between 7.2 and 12m Technical measures 120 minutes structural strength in case of fire

17. Financial feasibility Financial consequences of the adaptable single corridor building: 3% extra of the total investment costs.

18. Conclusion ‘the adaptable office’ Legal feasibility: Precondition in the development phase of the office building Technical feasibility Multi functional structure, replaceable skin and services. Central core building are already adaptable Single corridor buildings are not jet adaptable Financial feasibility 3% of the total investment costs.

19. Conclusion ‘the adaptable office’ ‘You cannot predict or control adaptability. All you can do is make room for it’(Brand,1994).

20. Location Housing market Office market

21. Location Mixed-use locations, centrally located

22. Arguments Sustainability Risk management Future value

23. Sustainability Extension of the lifetime of a building The construction is responsible for 30% of the pollution in a lifespan of 20 years. BREEAM-NL regards adaptability as sustainability enhancing Sustainability is more than energy saving measures: it must be part of the design concept

24. Risk management The possibility of functional adaptability will decrease the risk of structural vacancy Documentation of the adaptable possibilities will make transformation more comprehensible

25. Future value

26. Summary It is legally and technically feasible to develop adaptable office buildings …though only the structure seems to be reusable Central core buildings are easily adaptable, investments of 3% extra increase the adaptability of the single corridor type Mix-use locations are most interesting Adaptability carries only marginal costs and are therefore a commercially interesting investment