Drainage has become an increasingly important aspect of IOS development due to stricter environmental and planning standards.

Most local authorities now require Sustainable Drainage Systems (SuDS) to manage surface water runoff and minimise flood risk. Drainage design can be heavily influenced by the site’s topography, ground permeability, flood risk designations and any environmental constraints.

Drainage infrastructure generally account for 10-20% of total developments however can be significantly higher where large attenuation facilities are required.

Drainage costs can include:

• Attenuation tanks

• Swales

• Interceptor systems

• Drainage channels

• Balancing ponds

• Outfall connections

Security is fundamental to IOS operations because occupiers are typically storing valuable vehicles, plant, machinery, containers, or materials.

A comprehensive security package can add tens or even hundreds of thousands of pounds to total development costs, depending on site scale and complexity.

Security costs can include:

• Perimeter Fencing: Often either Palisade or Weldmesh fencing. Costs typically range between £140 and £280 per linear metre depending on level of security.

• CCTV and Monitoring: Modern facilities increasingly incorporate HD and thermal imaging, automatic number plate recognition (ANPR) and remote monitoring systems.

• Access Control: Premium developments frequently include electronic gates, keypad entry systems, vehicle barriers and remote access technology. The cost of installing effective security gates generally ranges between £10,000 and £20,000 depending on whether manual or automatic.

Historically, many IOS sites operated with limited utility infrastructure. However, occupier expectations are evolving. Now, many businesses require access to:

• Electricity: Costs can range from a several thousands of pounds to six figures depending on power requirements and any needed network reinforcements.

• Water: Costs driven by availability of local water and sewage infrastructure.

• Telecommunications and Fibre Broadband: Costs driven by local infrastructure,

• Electric Vehicle (EV) charging infrastructure: Estimated costs of between £15,000 and £20,000 per unit.

The cost of utility provision varies significantly depending on the site's existing facilities and its proximity to existing networks.

Further costs can also be experienced in the development of an IOS site, examples may include:

• Future Proofing: Installation of battery storage, solar generation and smart site technologies. Whilst resulting in higher upfront costs, such developments may enhance tenant demand and long-term asset value.

• Planning: Planning remains one of the most challenging aspects of UK IOS development due to local authority caution around environmental considerations, noise and visual impacts. Costs include highway, flood risk, environmental and ecological assessments whilst professional fees can easily reach £50,000 to £250,000+ on more complex schemes.

It is important to recognise that planning approval is not guaranteed. Many developers invest significant sums in surveys, design work, and professional advice before receiving planning consent.

As a result, planning risk remains one of the key challenges within the IOS sector.