The 2019 budget introduced a new capital allowance – the Structure and Buildings Allowance (SBA). It is available for qualifying costs of new commercial buildings where a contract for construction is entered into on or after 29 October 2018. The SBA provides a 2% writing down allowance which effectively gives relief over a 50 year period.
To put this into context, a £100,000 spend on a qualifying building would save a basic rate taxpayer £580 per year in tax (a higher rate taxpayer £840 and a company £380). Therefore, while any tax relief is welcome (if you are a taxpayer) the SBA is unlikely to make any credible difference to the commercial decision to invest in the building.