Building regulations 2025 - new non-domestic buildings: energy standard improvements - modelling report

Appendix D Cost Breakdown

The developed costs are based on the expert view of Currie & Brown’s cost specialists, drawing on evidence from their internal cost datasets, recent published cost data and information provided by suppliers.

The cost analysis is intended to reflect typical national costs from Q2 2025 that might be incurred by a public or private developer with reasonably efficient supply chain, design development and construction processes. However, costs incurred by individual organisations will vary according to their design, procurement strategies, the location of their activity (e.g. costs will be higher in more remote locations such as the Western Isles than in the Central Belt) and the detail of their project. These variations design, location and delivery method could result in a cost range of +/- c.30% or more (see Section 4.3). Notwithstanding these variations, the proportional uplifts associated with moving from one specification to another are likely to be relatively similar across different market segments^[10].

To provide context to the cost variations assessed in the study an indicative overall build cost (£ per m²) for each building archetype was estimated using Currie & Brown internal data. This figure is indicative of the level of cost that might be expected for a building built in accordance with the requirements of Section 6 2021. The build cost should be taken as indicative only as it is sensitive to a wide range of design and specification variables in addition to the economies of scale and regional variations discussed previously.

Base costs for future years are those for the 2025 price year, and subject to adjustments for learning for technologies that have not yet reached a mature market position. It should be noted that construction costs can vary considerably and rapidly with market conditions, particularly where activity levels result in a change in the availability of skills and materials. In these situations, it is not unusual to see quite large (several percentage points) change in overall costs over a period of months.

Table 130 includes details of the cost information used for each specification option, including any variations between building type, costs are only shown for those specifications that vary between the considered specification options.