Construction economics at early stage: order of cost estimating, life cycle costing and development appraisal of a proposed office complex

Abstract

Purpose

This study is carried out to demonstrate the computational practicalities of environmental construction economics necessary to offer early-stage cost advice. A case study of a private sector client’s development proposal is used. This is for the acquisition of a vacant freehold land of 1.2 acres brownfield site to develop a Grade A office complex with plans to achieve the BREEAM Excellent rating green building certification.

Design/methodology/approach

A three-stage methodology was deployed: Order of cost estimating, before life cycle costing and then development appraisal. The Order of Cost Estimate is generated using the BCIS online database, following the procedural guideline of the New Rules Measurement (NRM). The life cycle costing was carried out from an environmental perspective to explore two design options – Design A and Design B, in terms of which would offer the best value for money whilst reducing carbon emissions.

Findings

Based on the outcome of the life cycle costing computations, Design B was chosen as the advised development due to minimal differences in net present values and annual equivalents. Further evaluation of Design B, using the residual method of developmental appraisal was carried out, with all necessary assumptions made. From the extensive computations carried out, the project is considered unviable, as it reports a loss. Alternative use of the site or an alternative site is thus recommended to check if a greater return on investment is tenable.

Originality/value

The study narratively interweaves the application of three computational techniques that are core to offering early-stage cost advice.

Citation

Amadi, A.I. (2024), "Construction economics at early stage: order of cost estimating, life cycle costing and development appraisal of a proposed office complex", International Journal of Building Pathology and Adaptation, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/IJBPA-02-2023-0025