Is Building in CLT Cost Competitive?

A lot of construction decisions hinge on a narrow interpretation of the cost of delivery of each part of the project. However this is not the whole story, other factors can be just as or more important in determining the cost of a building; for example finance costs, the project management and administration costs, the building’s running costs (including heating), the ease of maintenance and the “liveability” of the building.

A Stora Enso study in 2018, looking at the costing of multi storey residential buildings showed that the “construction cost difference between timber and concrete….is small”; quantifying that cost difference at 3% (+/-2%) ie 1-5%. Off-setting the higher cost they found that there were compensating savings with practical advantages including:

· Lighter and cheaper foundations

· Programme advantages arising from achieving a weatherproof structure earlier eg earlier fit out

· Lower prelims due to faster build time

· Savings on finance costs and earlier income stream from faster build time.

Overall, they found that the construction time was about 20% quicker with CLT compared to a concrete build.

In another study of offices and commercial buildings, Stora Enso found that while the average reduction in the speed of the programme was of the order of 25-30% the reduction in the time taken to build the superstructure was 50% or more.

They concluded that this gain in speed would give the developers “reduced loan periods and less interest paid”, quicker returns to investors and the ability to complete more projects with the same team. In short, the benefits included reduced management costs, improved returns and process efficiencies.

These advantages were being achieved against a background of build costs being “comparable to traditional methods”.

Antony Fanshawe

23 March 2021